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HomeMy WebLinkAboutPINNACLE TOWNHOMES - PDP - 34-00A - SUBMITTAL DOCUMENTS - ROUND 2 - GEOTECHNICAL (SOILS) REPORTTA RECOMMENDED PREEVEiJTATIVE MAiNTENANCE POLICY FOR JOINTED CONCRETE PAVEMENTS Distress Type Distress Severn Recommended Maintenance ( Distress I l Type Distress I Severity Recommended Maintenance Blow-up low None Polished Aggregate No Seventy Levels Defined Groove Surface or Cver'ay Medium Fuli-0epth Concrete PatcIV Stab Replacement High Comer Break Low Seal Cracks Popouts. No Severity Levels None Defined Medium Full -Depth Concrete Patch High Divided Slab Low Seal Cracks Pumping No Severity Levels Defined Underseal, Seal cracksljoints and Restore Load Transfer Medium Slab Replacement High Durability Cracking Low None Punchout Low Seal Cracks Medium Full -Depth Patch Medium -till Concrete Patch High Slab Replacement High Faulting Law None Railroad Crossing Low No Polity for this Project Medium Grind Medium High High _ Joint Seal Low None Scaling Map Cracking Law None I Crazing Medium Reseal Joints Medium Slab Replacement, Full -depth Patch, or Overlay High High Lane/Shoulder Drop-off Low Regrade and Fill Shoulders to Match Lane Height Shrinkage Cracks - No Severity Levels Defined None Medium High Linear Cracking Longitudinal, Transverse and Low Clean & Seal all Cracks t pallin g Comer Low None Diagonal Cracks Medium Medium Partial-0epth Concrete Patch High Full -Depth Patch High Large Patching and utility Cuts Low None Spalling (Joint) Low None Medium Seal Cracks or Replace Patch Medium Partial -Depth Patch High High Reconstrct Joint Small Patching Low None Medium Replace Patch High lrerracon TABLE D1 RECOMMENDED PREVENTATWE MAINTENANCE POLICY FOR ASPHALT CONCRETE PAVWENTS Distress Distress I Recommended Maintenance Distress Distress Reccmmendr_d Maintenance Type Severity Type Severity Alligator Low None Patching & Low None Cracking Utility Cut Patching Medium Full -Depth Asphalt Concrete Patch Medium Full -Depth Asphalt Concrete Patch High High Bleeding Low None Polished Low None Aggregate Medium Surface Sanding Medium High Shallow AC Patch High Fog Seal Block Low None Potholes Low Shallow AC Patch Cracking Medium Clean & Seal All Cracks Medium Full -Depth Asphalt Concrete Patch High High Bumps & Sags Low None Railroad Crossing Low T Policy for This Project Medium Shallow AC Patch Medium High Full -Depth Patch High Corrugation Low None Rutting Low None Medium Full -Depth Asphalt Concrete Medium Shallow AC Patch Patch High High Full -Depth Patch Depression Low None Shoving Low None Medium Shallow AC Patch Medium Mill & Shallow AC Patch High Full -Depth Patch High Edge Low None Slippage Low None Cracking Cracking 1.1edium Seal Cracks Medium Shallow Asphalt Concrete Patch High Full -Depth Patch High Joint Reflection Low Clean & Seal All Cracks Swell Low None Medium Medium Shallow AC Patch High Shallow AC Patch High Full -Depth Patch Lane/Shoulder Drop -Off Low one Weathering Low 8 Ravelling Fog Seal h1 edium Regrade Shoulder Medium High High Longitudinal & Low Nora Transverse Cracking Medium Clean & Seal All Cracks High 1rr�rr�rnn ----- - ---- - . UNIFIED SOIL CLASSIFICATION SYSTEM Soil Classification Criteria for Assigning Group Symbols and Group Names Using Laboratory Taste Group Symbol Group Name s Coarse -Grained Soils more than Gravels more than 50% of coarse Clean Gravels Less than 506 finest Cu > 4 and 1 < Cc <3' G:"! Well -graded gravel'. 50% retained an fraction retained on No. 200 sieve No. 4 sieve Cu < 4 and/or 1 > Cc > 3` GP Poorly graded gravel` Gravels with Fines more than 12% finest Fines classify as ML or MH G1%1 Silty gravel,G,H Fines classify as CL or CH GC Clayey gravelF•G•" Sands 50% or more Clean Sands Les; Cu > 6 and 1 < Cc < 3' SW Well -graded sand' of coarse fraction than 5% fines' passes No. 4 sieve Cu < 6 and/or 1 > Cc > 3' SP Poorly graded sand' Sands with Fines Fines classify as ML or MH SM Silty sand"-'`' • more than 12% fines° Fines Classify as CL or CH SC Clayey sandG•'u Fine -Grained Soils Silts and Clays inorganic PI > 7 and plots on or above "A line' CL Lean clay'•`•"' 50% or more Liquid limit less passes the than 50 PI < 4 or plots below "A" line' NIL Silt'LL•M No. 200 sieve ' organic Liquid limit -oven dried Organic clay"-`-" < 0.75 OL - Liquid limit - not dried Organic silt`-L•M•o Silts and Clays inorganic PI plots on or above "A" line CH Fat clay"•LM Liquid limit 50 or more PI lots below "A" line MH Elastic Silt%•LM organic Liquid limit - oven dried Organic clayKL"'•' - < 0.75 OH Liquid limit - not dried Organic silt'LL•'"•O Highly organic soils Primarily organic matter, dark In color, and organic odor PT Peat ABased on the material passing. the 3-in... ' !`If soil contains 15 to 29% plus No. 200, add (75-mm) sieve - 'If SCu=D`0 /D10 Cc = (D30) _ "with sand" or "with gravel", whichever 1s ' field sample contained cobbles or D10 x D,0 predominant. boulders, or both, add :with cobbles.or. AIt soil contains > 30% plus No. 200 boulders, or. both" to group name. predominantly sand, add "sandy" to group 'Gravels with 5 to"I2% fines require dual; .r-'If soil contains >-15% sandy"add ."with ' , _.- : - name. . symbols: sand' to group name. '"If soil contains > 30% plus No. 200, GW-GM well -graded gravel with silt Olt fines classify as CL-ML, use dual symbol predominantly gravel, add "gravelly' to group GW-GC well -graded gravel with clay GC -GM, or SC-SM. name. GP -GM poorly graded gravel with silt "If fines are organic, add "with organic fines" "PI > 4 and plots on or above "A" line. GP -GC poorly graded gravel with clay to group name. GPI < 4 or plots below "A" line. "Sands with 5 to 12% fines require dual 'If soil contains > 15% gravel, add "with 'PI plots on or above "A" line. symbols: gravel" to group name. 'PI plots below "A" line. SW-SM well -graded sand with silt 'If Atterberg limits plot in shaded area, soil is SW -SC well -graded sand with clay a CL-ML, silty clay. SP-SM poorly graded sand with silt SP-SC poorly graded sand with clay "Gna-Q.ain,a I�� pain.° „-..n. ena Iran°an I oar yralnaa • as l: lot-Oi "ar.aanlal " a"ta LL C!.! -loan •J .� ���� it - C.71 ILL - !C) �L Ea.aC<n el V - °na V in�..�a1-LLo.>I(�l-ell ••-I G� �f I �•� I � I I 0�0 I � � I �MH OR OH MIL ik OL t o to to :° !.: •° !o c! 7c _" so LIQUID LIMIT (LL) lrerraconj a REPORT TERMINOLOGY (Eased on ASTM D653) Expansive Potential The potential of a soil to expand (increase in volume) due to absorption of moisture. Finished Grade The final grade created as a part of the project. Footing A portion of the foundation of a structure that transmits loads directly to the soil. Foundation The lower part of a structure that transmits the loads to the soil or bedrock. Frost Depth The depth of which the ground becomes frozen during thew inter season. Grade Beam A foundation element or wall, typically constructed of reinforced concrete, used to span between other foundation elements such as drilled piers. Groundwater Subsurface water found in the zone of saturation of soils, or within fractures in bedrock. Heave Upward movement. Lithologic The characteristics which describe the composition and texture of soil and rock by observation. Native Grade The naturally occuring ground surface. Native Soil Naturally occurring on -site soil, sometimes referred to as natural soil. )ptimum Moisture Thewater,content;at which a soil :can.be compacted to a maximum dry unit Content weight by;:a:giv.en.:.compact ive.effort::, Perched Water Groundwater, usually of limited area maintained above a normal water. elevation by the presence of an intervening relatively impervious continuing stratum. Scarify To mechanically loosen soil or break down existing soil structure. Settlement Downward movement. Skin Friction (Side The frictional resistance developed between soil and an element of structure Shear) such as a drilled pier or shaft. . Soil (earth) Sediments or other unconsolidated accumulations of solid particles produced by the physical and chemical disintegration of rocks, and which may or may . not contain organic matter. Strain The change in length per unit of length in a given direction. Stress The force per unit area acting within a soil mass. Strip To remove from present location. Subbase A layer of specified material in a pavement system between the subgrade and base course. Subgrade The soil prepared and compacted to support a structure, slab or pavement system. Irerracon REPORT TERMINOLOGY (Based on ASTM D653) Allowable Soil The recommended maximum contact -stress developed at the interface of the Bearing Capacity foundation element and the supporting material. Alluvium Soil, the constituents of which have been transported in suspension by flowing water and subsequently deposited by sedimentation. Aggregate Base A layer of specified material placed on a subgrade or subbase usually beneath Course slabs or pavements. Backfill A specified material placed and compacted in a confined area. Bedrock A natural aggregate of mineral grains connected by strong and permanent - cohesive forces. Usually requires drilling, wedging, blasting or other methods of - extraordinary force for excavation. Bench A horizontal surface in a sloped deposit. Caisson (Drilled pier A concrete foundation element cast in a circular excavation which may have an or Shaft) enlarged base. Sometimes referred to as a cast -in -place pier or drilled shaft. Coefficient of A constant proportionality factor relating normal stress and the corresponding Friction shear stress at which sliding starts between the two surfaces. Col/uvium Soil, the constituents of which have been deposited chiefly by gravity such as at the foot of a slope or cliff. Compaction The densification.:of.a soil:by means:of_ mechanical manipulation. Concrete Slab -on- A concrete surface layercast:,directly upon a base, subbase or subgrade, and Grade typically used as a floor system. Differential: Unequal settlement or heave.between, or within foundation elements of a Movement structure. Earth Pressure The pressure or force exerted by soil on any boundary such as a foundation wall. ESAL Equivalent Single Axle Load, a criteria used to convert traffic to a uniform standard, (18,000 pound axle loads).. Engineered Fill Specified material placed and compacted to specified density and/or moisture conditions under observations of a representative of a geotechnical engineer. Equivalent Fluid A hypothetical fluid having a unit weight such that it will produce a pressure against a lateral support presumed to be equivalent to that produced by the actual soil. This simplified approach is valid only when deformation conditions are such that the pressure increases linearly with depth and the wall friction is neglected. Existing Fill (or Materials deposited through the action of man prior to exploration of the site. man-made fill) Existing Grade The ground surface at the time of field exploration. lferracon J LABORATORY TESTS SIGNIFICANCE AND PURPOSE TEST I SIGNIFICANCE PURPOSE California Used to evaluate the potential strength of subgrade soil, Pavement Bearing subbase, and base course material, including recycled Thickness Ratio materials for use in road and airfield pavements. Design Consolidation Used to develop an estimate of both the rate and amount of I Foundation both differential and total settlement of a structure. Design Direct Used to determine the consolidated drained shear strength of Bearing Capacity, Shear soil or rock. Foundation Design & Slope Stabilitv Dry Density Used to determine the in -place density of natural, inorganic, fine-grained soils. Index Property Soil Behavior Expansion Used to measure the expansive potential of fine-grained. soil and to provide a basis for swell potential classification. Foundation & Slab Design Gradation Used for the quantitative determination of the distribution of particle sizes in soil. Soil Classification - Liquid & Plastic limit, Plasticity Used as an integral part of engineering classification systems to characterize the fine-grained fraction of. soils, and to specify the fihe-.grained,fraction:of.construction materials. Soil Classification Index Permeability Used to determine the capacity of soil or rock to conduct a liquid or gas. Groundwater. Flow Analysis pH Used to determine the degree of acidity or alkalinity of a soil. Corrosion Potential Resistivity Used to indicate the relative ability of a soil medium to carry osion Potent electrical currents. al R-Value Used to evaluate the potential strength of subgrade soil, Pavement subbase, and base course material, including recycled Thickness materials for use in road and airfield pavements. Design Soluble Used to determine the quantitative amount of soluble Corrosion Sulphate sulfates within a soil mass. Potential Unconfined To obtain the approximate compressive strength of soils that Bearing Capacity Compression possess sufficient cohesion to permit testing in the Analysis unconfined state. for Foundations Water Used to determine the quantitative amount of water in a soil I Index Property Soil Behavior Content mass. .lferracon r DRILLING AND EXPLORATION DRILLING & SAMPLING SYMBOLS: R : Ring Barrell - 2.42" I.D., 3" O.D., unless otherwise noted SS : Split Spoon - 1_" I.D., 2" O.D., unless otherwise noted PS : Piston Sample ST : Thin -Walled Tube - 2" O.D., unless otherwise noted WS : Wash Sample PA : Power Auger FT : Fish Tail Bit HA : Hand Auger RB : Rock Bit DS : Diamond Bit = 4", N, B BS : Bulk Sample AS : Auger Sample PM : Pressure Meter HS : Hollow Stem Auger DC : Dutch Cone WB : Wash Bore Penetration Test: Blows per foot of a 140 pound hammer falling 30 inches on a 2-inch O.D. split spoon, except where noted. WATER LEVEL -MEASUREMENT SYMBOLS: WL :Water Level WS : While Sampling WCI : Wet Cave in WD :While Drilling DCI : Dry Cave in BCR : Before Casing Removal AB : After Boring ACR : After Casting Removal Water levels indicated on the boring logs are the levels measured in the borings at the time indicated. In pervious soils, the indicated levels may reflect the location of groundwater. In low permeability soils, the accurate determination of groundwater levels is not possible with only short term observations. DESCRIPTIVE SOIL CLASSIFICATION: Soil Classification is based on the Unified Soil Classification system and the ASTM Designations D-2487 and D-2488. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; they are described as: boulders, cobbles, gravel'or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are described as: clays, if they are plastic, and silts if they are slightly plastic or non -plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition.* to gradation, coarse grained soils are defined on the basis of.their relative in -place density and fine grained soils on the basis of their consistency. Example: - Lean clay with sand, trace gravel, stiff (CL); silty sand, trace gravel, medium dense ISM). CONSISTENCY OF FINE-GRAINED SOILS: Unconfined Compressive Strength, Ou, psf Consistency < 500 Very Soft 500 - 1,000 Soft 1,001 - 2,000 Medium 2,001 - 4,000 Stiff 4,001 - 8,000 Very Stiff 8,001-16,000 Very Hard RELATIVE PROPORTIONS OF SAND AND GRAVEL Descriptive Term(s) (of Components Also Percent of Present in Sample) Dry Weight Trace < 15 With 15 - 29 Modifier > 30 RELATIVE PROPORTIONS OF FINES Descriptive Term(s) (of Components Also Percent of Present in Sample) Dry Weight Trace < 5 With 5-12 Modifier > 12 RELATIVE DENSITY OF COARSE -GRAINED SOILS: N-Blows/ft. Relative Density 0-3 Very Loose. 4-9 Loose 10-29 Medium Dense 30-49 Dense 50-80 Very Dense 80+ Extremely Dense GRAIN SIZE TERMINOLOGY Major Component of Sample Size Range Boulders Over 12 in. (300mm) Cobbles 12 in. to 3 in. (300mm to 75mm) Gravel 3 in. to #4 sieve (75mm to 4.75mm) Sand n4 to #200 sieve (4.75mmto 0.075mm) Silt or Clay Passing #200 Sieve - (0.075mm) lferracon J M1 r r 2 n O z N O a 4 z 6 8 10 0.1 APPLIED PRESSURE, TSF 10 Specimen Identification Classification Yd, pcf WC,% • 5 3.Oft SILTY CLAYEY SAND 107 17 Notes: CONSOLIDATION TEST Project: Pinnacle Townhomes Irerracon Site: SW of Prospect and Lemay Fort Collins, Colorado Job #: 20015202 Date: 10-10-01 0.80 0.78 0.76 0.74 0.72 0 � 0.70 0 0 0.68 . 0.66 0.64 0.62 0.60 0.1 1 10 PRESSURE, psf 0 3 0 Specimen Identification Classification pcf WC% r u 4 6 8 1 1 APPLIED PRESSURE, TSF Specimen Identification Classification Yd, pcf WC,% 1*1 3 3.Oft SANDY LEAN CLAY 95 24 Notes: CONSOLIDATION TEST Project: Pinnacle Townhomes Irerraccin Site: SW of Prospect and Lemay Fort Collins, Colorado Job #: 20015202 Date: 10-10-01 E PRESSURE, psf Specimen Identification Classification Yd, pcf WC% 1*1 1 3.Oft SILTY CLAYEY SAND 115 12 Notes: CONSOLIDATION TEST Project: Pinnacle Townhomes Irerracon Site: SW of Prospect and Lemay Fort Collins, Colorado Job #: 20015202 Date: 10-10-01 r r 10 APPLIED PRESSURE, TSF Specimen Identification Classification Yd, pcf WC% • 1 3.Oft SILTY CLAYEY SAND 115 12 Notes: CONSOLIDATION TEST Project: Pinnacle Townhomes Irerracon Site: SW of Prospect and Lemay Fort Collins, Colorado Job #: 20015202 Date: 10-10-01 Ck. - 0 . nllllu■lllln�■■ ,1�■�llnln��inl�� .11■■nll�l�■®�i�u���►\I�ill�i■Innl�■■lu�ll�■■ 11■■non■�I�,�II�i■lu'1.1��►ilnlll�■■IIIIIII■� • IN M M 11■■n11111■®IIIIIII\■nIn11■�ii1111■■n11111■� limmillillimmullillsoill EL SAND COBBLES SILT OR CLAY fine coarse medium fine Specimen Idenbification Specimen Identification M.- VW "141 rerrac'on off coarse U.S. SIEVE OPENING IN INCHES ULS.'SIEVE NUMBERS HYDROMETER txlo, .5x10' 9x1o' t_k10 .yx10 m Cr plo 6- al• 6 ° 3 6iu 14 io 20 eu 40 cu 60 wu I 11 I I II I I 14 III I I l t I t III I' 11 1 :1 1 1 1 1 GRAIN SIZE IN MILLIMETERS COBBLES GRAVEL SAND SILT OR CLAY coarse fine coarse medium fine Specimen Identification Classification LL I PL I PI Cc I Cu • 1 4.Oft LEAN CLAY with SAND(CL) 43 17 26 y 1 9.Oft SILTY SAND with GRAVEL ♦ 2 3.Oft SANDY LEAN CLAY(CL) 37 15 22 * 3 9.0ft SILTY SAND with GRAVEL S O 4 3.Oft SANDY LEAN CLAY(CL) 46 18 28 g Specimen Identification D100 D60 D30 D10 %Gravel %Sand %Silt %Clay 8 • 1 4.Oft 4.75 0.0 22.0 78.0 u x 1 9.Oft 19 1.459 0.286 13.0 72.0 15.0 r ♦ 2 3.Oft 4.75 0.15 0.0 48.0 52.0 * 3 9.Oft 19 I 2.352 0.376 27.0 58.3 14.7 N O 4 3.0ft 4.75 I 0.0 36.0 64.0 R GRAIN SIZE DISTRIBUTION Project: Pinnacle Townhomes N Irerraccin Site: SW of Prospect and Lemay Fort Collins, Colorado Job #: 20015202 Date: 10-10-01 LOG OF WELL NO. 5 Page 1 of 1 CLIENT ARCHITECT / ENGINEER Pinnacle Fort Collins, LLC SITE SW of Prospect and Lemay PROJECT Fort Collins, Colorado Pinnacle Townhomes SAMPLES TESTS WELL Oo DESCRIPTION DETAIL m o w z F Z p to m i w p z LU a F x TOP OF CASING: 4955.1 ft a w U rn � c_ U w F O a� ¢O 3 CJg" (9 GROUND SURFACE ELEV.: 4951.7 ft o z W C5 m c) o 0. _., a o ^. 0.5 6" TOPSOIL 4951 47/31/53 SANDY LEAN CLAY trace GRAVEL 1 SS 12 10 12.6 Tan, brown, dry to moist, stiff to very stiff 3 4948.5 SILTY CLAYEY SAND trace GRAVEL 2 ST 12 19.7 99 14.5 Tan, brown, dry to moist, mediium dense to 3 SS 12 4 10.4 loose 4947 -'• 5 SILTY SAND with GRAVEL Tan, brown, moist to wet, medium dense 4 SS 12 1 19 12.2 10 4941.5 .' ; 10 WEATHERED SILTSTONE/SANDSTONE Tan, brown, moist, poorly cemented SWELL = 5 SS 12 45 21.5 15 4936.5 ; . 15 175 psf SILTSTONE/SANDSTONE Tan, gray, moist, cemented to well cemented 19.5 4932 6 SS 6 15010.5116.7 BOTTOM OF BORING 5 u Z 0 U a C w The stratification lines represent the approximate boundary lines behreen soil and rock types: in -situ, the transition may be gradual. 0 WATER LEVEL OBSERVATIONS, ft BORING STARTED 9-25-01 5.0 EDIT 5.1 AB OBING CO ME 5-01 DFOREMAN 9 2ARS Irerracon 75 WL RIG WL Water Checked 9/26/01 APPROVED DAR JOB # 20015202 LOG OF WELL NO. 4 page 1 of 1 CLIENT ARCHITECT / ENGINEER Pinnacle Fort Collins, LLC SITE SW of Prospect and Lemay PROJECT Fort Collins, Colorado Pinnacle Townhomes SAMPLES TESTS WELL 0 DESCRIPTION DETAIL JO } az ~o U c C L c H Z F o �?o D_ Cf)r w o TOP OF CASING: 4956.9 ft °- O a 00 w p a z < O >. tr O S �- C9 GROUND SURFACE ELEV.: - 4954.0 ft o z rnm �O o a JaA 0.5 6" TOPSOIL 4953.5 SANDY LEAN CLAY trace GRAVEL 1 SS 12 10 15.2 Tan, brown, dry to moist, stiff to very stiff 46/28/64 2 ST 12 25.4 93 4 asso SILTY CLAYEY SAND trace GRAVEL 3 SS 12 4 21.3 5 Tan, brown, dry to moist, mediium dense to 4949'.;" loose 5 SILTY SAND with GRAVEL Tan, brown, moist to wet, medium dense Y 11110 4 SS 12 25 21.0 4944... " . •• 10 WEATHERED SILTSTONEJSANDSTONE 114 Tan, brown, moist to wet, poorly cemented 4940 SILTSTONE/SANDSTONE 5 SS 12 50 20.2 : 15 Tan, gray, moist, cemented to well 4939 cemented 15 BOTTOM OF BORING The stratification lines represent the approximate boundary lines between soil and rock types: in -situ, the transition may be gradual. WATER LEVEL OBSERVATIONS, ft Irerracon BORING STARTED WL SL 6.0 6.3 AB CO ME DFOREMAN 9-2 WL � 7Z BORING 75 ARS WL Water Checked 9/26101 APPROVED DAR JOB # 20015202 LOG OF WELL NO. 3 Page 1 of 1 CLIENT ARCHITECT / ENGINEER Pinnacle Fort Collins, LLC SITE SW of Prospect and Lemay PROJECT Fort Collins, Colorado Pinnacle Townhomes SA+APL"ES TESTS WELL c� DESCRIPTION DETAIL p _' o J m C u o Z _ = N W C1 W > O Z CW Z Z Uj .3 Hm~ Q7LL W TOP OF CASING: 4956.5 ft a W. u> > a c� W f O a� FW a0 M� -' -' �0� (9 GROUND SURFACE ELEV.: 4953.3 it o D z N m t> o a o to . �P 0.5 6" TOPSOIL 4953 SANDY LEAN CLAY trace GRAVEL 1 SS 12 11 11.4 Tan, brawn, dry to moist, stiff to very stiff 2 ST 12 25.0 92 4 4949.5 0.0011 SILTY CLAYEY SAND trace GRAVEL 3 SS 12 4 31.4 Tan, brown, dry to moist, medium dense to 5 loose 6 4947.5 ;• •. SILTY SAND with GRAVEL SZ Tan, brown, moist to wet, medium dense X. 4 SS 12 22 9.7 10 12.5 4941 WEATHERED SILTSTONE/SANDSTONE Tan, brown, gray, moist to wet, poorly cemented 5 SS 12 34 18.9 15 4938.5 15 BOTTOM OF BORING z ' 5 0 u a c wThe stratification lines represent the approximate boundary lines between soil and rock types: in -situ, the transition may be gradual. a WATER LEVEL OBSERVATIONS, ft BORING STARTED 9-25-01 WL 6.5 WD 7.6 AB CO DFOREMAN 9-2ARS 3Z Irerracon WL ROBING CM -75 WL Water Checked 9/26101 APPROVED DAR I JOB # 20015202 LOG OF WELL NO. 2 Page 1 of 1 CLIENT ARCHITECT / ENGINEER Pinnacle Fort Collins, LLC SITE SW of Prospect and Lemay PROJECT Fort Collins, Colorado Pinnacle Townhomes SAMPLES TESTS WELL cD DESCRIPTION DETAIL p _' OJ m y o x rw cl U c } C w z F" ?o a F rn Co w o . wH ��a TOP OF CASING: 4957.0 it w N j a U a O ¢ O C 05 0 GROUND SURFACE ELEV.: 4953.4 It o z a U) m U o n T a o 6" TOPSOIL 4953 SILTY CLAYEY SAND trace GRAVEL 1 SS 12 16 5.0 Tan, brown, dry to moist, medium dense to loose 37/22/52 2 ST 12 13.7 105 Lenses of Sandy Lean Clay: Brown, moist, soft 3 SS 12 4 17.5 s 8 4945.5 . • ' _ SILTY SAND with GRAVEL Tan, brown, moist to wet, medium dense to dense 4 1 SS 1 8 50/0.7 27.5 to • :. 13 4940.5. WEATHERED SILTSTONE/SANDSTONE Tan, brown, moist to wet, poorly cemented s Ss 12 26 22.1 15 4938.5 15 BOTTOM OF BORING 3 z D e WThe stratification lines represent the approximate boundary lines between soil and rock types: in -situ, the transition may be gradual. 'c R WATER LEVEL OBSERVATIONS, ft Irerracon BORING STARTED 9-25-17' WL 8.0 WD IT 7.2 AB BORING COMPLETED9 2ARS WL J Y RIG WL Water Checked 9/26/01 APPROVED DAR I JOB # 20015202 t4t LOG OF WELL NO. 1 Page 1 of 1 CLIENT ARCHITECT / ENGINEER Pinnacle Fort Collins, LLC SITE SW of Prospect and Lemay PROJECT Fort Collins, Colorado Pinnacle Townhomes SA PLES TESTS WELL 0 O DESCRIPTION DETAIL m e o Hu �Oo F f- _ = fn W W i O Zr/1 0 RW Z ��N � TOP OF CASING: 4959.1 tt o- w U cn M n w a� � Z <0 0- a5� 0 IGROUND SURFACE ELEV.: 4956.4 It o Z x rn ca O o a 7 0- o .. '. 0.5 6" TOPSOIL 4956 SILTY CLAYEY SAND trace GRAVEL 1 SS 12 13 10.0 Tan, brown, dry to moist, medium dense to loose 2 ST 12 20.6 105 Lenses of Sandy Lean Clay: Brown, 3 SS 12 2 29.9 moist, soft 43/26/78 5 7 YZ 4949.5 SILTY SAND with GRAVEL - Tan, brown, moist to wet, medium dense 4 SS 12 32 8.8 10 13 4943.5 WEATHERED SILTSTONE/SANDSTONE Tan, brown, moist to wet, poorly cemented 5 SS 12 25 19.8 15 4941.5 15 BOTTOM OF BORING z 3 z a Y+ The stratification lines represent the approximate boundary lines between soil and rock types: In -situ, the transition may be gradual. a WATER LEVEL OBSERVATIONS, ft BORING STARTED 9-25-01 WL 7.0 WD 7.2 Al CO DFOREMAN 9-2 3Z Irerracon WL ROBING CME-75 AIRS WL Water Checked 9/26/01 APPROVED DAR I JOB # 20015202 7 95) 25) TOM: SEWER MANHOLE RIMS LEGEND ELEV. = 4952.95 FIGURE 3: GROUNDWATER CONTOUR MAP PINNACLE TOILNHOMES APPROX. TEST BORING LOCATION SOUTP OF E. PROSPECT ROAD, NORTI-I OF SPRING CREEK NOTE: FORT COLLINS, COLORADO (4956.94) TOP OF CASING ELEVATION (FT) GROUNDWATER CONTOURS WERE ESTIMATED USING THE 'SURFER' FrejKtNe'70015702 Pejeet"�"g" DAR �n Toren-G-a 9.3 DEPTH TO GROUNDWATER Designed Bg, DAR c�'-'�11 u male, I' PROGRAM FROM GOLDEN 11 (4947.641 GROUNDWATER ELEVATION SOFTWARE BASED ON DATA DAR 301 N. HOW06 Street Date: 9/16/01 COLLECTED FROM TB NOe. 1-5 ON Approved ey, DAR Fort Colllna, Colorado W571 Drawn N, ,�4947-- GROUNDWATER CONTOURS 9/26/01. ACTUAL CONDITIONS MAY SD VARY. F"• Name' 5202FIG3 Figtr• No. 3 LEGEND APPROXIMATE TEST BORING LOCATION DIAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUC71ON PURPOSES. (VAyN Jl�l FIGURE 2: SITE PLAN PINNACLE TOUNNOMES SOUTH OF E. PROSPECT ROAD..NORTW OF SPRING CREEK FORT COLLINS, COLORADO Project Nngr, DAR l re r ra c o n 301 N. Hawes Street Fort Collins, Colorado 80521 Fo�ecl No.2CJ015?O? Derlgned By, DAR Scale, 1 r W, Checked Mp DAR Da1C. cinalo1 Approved 59, DAR Dramn By: 5DC Flie Name, 5202FIG2 FI[ove No. 2 0 m' m :✓ 4 SITELOCATION 'e SNlALlO\^! RD �NNIq{ .. O IVY m a F60Or SWALLOW BND fFco T iSPRINGV� p EN TFCftpLN !s s GROVEWOOD FIC--URE is VICINITY NAP PINNACLE TOLLNHONES SOUTH C: E. PROSPECT ROAD, NORTH OF SPRING CREEK FORT COLLINS, COLORADO Prolxt Ngr: DAR lrerracan Project No.20015 UUU J Deslgnad ey: DAR Seale` I ChaCked 5j: DAR Date: 13/21 301 K Howes Street By: DA4 Draw Sy: V DIAGApproved IS FOR GENERAL LOCATION ONLY, Fort Collins, Colorado 50521 Fila Na.ne: 5202r-IGI Figva No. .I AND ISM ` NO S NOT INTENDED FOR CONSTRUCTION PURPOSES. Geotechnical Engineering Report Pinnacle P.U.D. - Townhomes Project No. 20015202 Terracon should be well compacted and free of all construction debris to reduce the possibility of moisture infiltration. Downspouts, roof drains or scuppers should discharge into splash blocks or extensions when the ground surface beneath such features is not protected by exterior slabs or paving. Sprinkler systems should not be installed within 5 feet of foundation walls. Landscaped irrigation adjacent to the foundation system should be minimized or eliminated. GENERAL COMMENTS Terracon should be retained to review the final design plans and specifications so comments can be made regarding interpretation and implementation of our geotechnical recommendations in the design and specifications. Terracon also should be retained to provide testing and observation during excavation, grading, foundation and construction phases of the project. The analysis and recommendations presented in this report are based upon the data obtained from the borings performed at the indicated locations and from other information discussed in this report. This report does not reflect variations, which may occur between borings or across the site. The nature and extent of such variations may not become evident until construction. If variations appear, it will be necessary to reevaluate the recommendations of this report. The scope of services for this project does not include either specifically or by implication any environmental assessment of the site or identification of contaminated or hazardous materials or conditions. If the owner is concerned about the potential for such contamination, other studies should be undertaken. This report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance . with generally accepted geotechnical engineering practices. No warranties, express or implied, are intended or made. In the event that changes in the nature, design, or location of the project as outlined in this report, are planned, the conclusions and recommendations contained in this report shall not be considered valid unless Terracon reviews the changes, and either verifies or modifies the conclusions of this report in writing. 17 Geotechnical Engineering Report Terracon Pinnacle P.U.D. — Townhomes Project No. 20015202 Additional Design and Construction Considerations Exterior Slab Design and Construction Exterior slabs -on -grade, exterior architectural features and utilities founded on or in backfill may experience some movement due to the volume change of the backfill. Potential movement could be reduced by: • minimizing moisture increases in the backfill • controlling moisture -density during placement of backfill • using designs which allow vertical movement between the exterior features and adjoining structural elements • placing effective control joints on relatively close centers Underground Utility Systems All piping should be adequately bedded for proper load. distribution. It is suggested that clean, graded gravel compacted to 75 percent of Relative Density ASTM D4253 be used as bedding. Where utilities are excavated below groundwater, temporary dewatering will be required during excavation, pipe placement and backfilling operations for proper construction. Utility trenches should be excavated on safe and stable slopes in accordance with OSHA regulations as discussed above. Backfill should consist of the on -site soils or imported material approved by the geotechnical engineer. The pipe backfill should be compacted to a minimum of 95 percent of Standard Proctor Density ASTM D698. Corrosion Protection Results of soluble sulfate testing indicate that ASTM Type I Portland cement is suitable for all concrete on and below grade. However, if there is no, or minimal cost differential, use of ASTM Type II Portland cement is recommended for additional sulfate resistance of construction concrete. Foundation concrete should be designed in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4. Surface Drainage Positive drainage should be provided during construction and maintained throughout the life of the proposed project. In areas where sidewalks or paving do not immediately adjoin the structure, we recommend that protective slopes be provided with a minimum grade of approximately 5 percent for at least 10 feet from perimeter walls. Backfill against footings, exterior walls, and in utility and sprinkler line trenches 16 Geotechnical Engineering Report Pinnacle P.U.D. — Townhomes Project No. 20015202 Material Terracon Minimum Percent fASTM D698) Scarified subgrade soils........................................................... :............. 95 On -site and imported fill soils: Beneathfoundations..................................................................95 Beneathslabs............................................................................95 Beneath pavements...................................................................95 Aggregate base (beneath slabs)............................................................95 Miscellaneous backfill (non-structural areas).........................................90 On -site clay for backfill or grading purposes should be compacted within a moisture content range of 2 percent below, to 2 percent above optimum. Imported or on -site granular soils should be compacted within a moisture range of 3 percent below to 3 percent above optimum unless modified by the project geotechnical engineer. Excavation and Trench Construction Excavations into the on -site soils may encounter caving soils and groundwater, depending upon the final depth of excavation. The individual contractor(s) should be made responsible for designing and constructing stable, temporary excavations as required to maintain stability of both the excavation sides and bottom. All excavations should be sloped or shored in the interest of safety following local, and federal regulations, including current OSHA excavation and trench safety standards. The soils to be penetrated by the proposed excavations may vary significantly across the site. The preliminary soil classifications are based solely on the materials encountered in widely spaced exploratory test borings. The contractor should verify that similar conditions exist throughout the proposed area of excavation. If different subsurface conditions are encountered at the time of construction, the actual conditions should be evaluated to determine any excavation modifications necessary to maintain safe conditions. As a safety measure, it is recommended that all vehicles and soil piles be kept to a minimum lateral distance from the crest of the slope equal to no less than the slope height. The exposed slope face should be protected against the elements. 15 Geotechnical Engineering Report Pinnacle P.U.D. — Townhomes Project No. 20015202 Terracon All exposed areas which will receive fill, once properly cleared where necessary, should be scarified to a minimum depth of eight inches, conditioned to near optimum moisture content, and compacted. It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment. . Depending upon depth of excavation and seasonal conditions, groundwater may be encountered in excavations on the site. Pumping from sumps may be utilized to control water within excavations. Well points may be required for significant groundwater,flow, or where excavations penetrate groundwater to a significant depth. Subgrade Preparation Subgrade soils beneath interior and exterior slabs, and beneath pavements should be scarified; moisture conditioned and compacted to a minimum depth of 8 inches. The moisture content and compaction of subgrade soils should be maintained until slab or pavement construction. Fill Materials and Placement Clean on -site soils or approved imported materials may be used as fill material and are suitable for use as compacted fill beneath interior or exterior floor slabs. Imported soils (if required) should conform to the following: Gradation Percent finer by weight (ASTM C1361 6".........................................................................................................100 3"....................................................................................................70-100 No. 4 Sieve.....................................................................................50-100 No. 200 Sieve................................................................................50 (max) • Liquid Limit.......................................................................30 (max) • Plasticity Index.................................................................15 (max) Engineered fill should be placed and compacted in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift. Recommended compaction criteria for engineered fill materials are as follows: 14 Geotechnical Engineering Report Pinnacle P.U.D. — Townhomes Project No. 20015202 Terracon Longitudinal and transverse joints should be provided as needed in concrete pavements for expansion/contraction and isolation. Joints should be constructed in accordance with ACI procedures. Preventative maintenance should be planned and provided for through an on -going pavement management program in order to enhance . future pavement performance. Preventative maintenance activities are intended to slow the rate of pavement deterioration, and to preserve the pavement investment. Preventative maintenance consists of both localized maintenance (e:g. crack sealing and patching) and global maintenance (e.g. surface sealing). Preventative maintenance is usually the first priority when implementing a planned pavement maintenance program and provides the highest return on investment for pavements. Recommended preventative maintenance policies for asphalt and jointed concrete pavements, based upon type and severity of distress, are provided in Appendix C. Prior to implementing any maintenance, additional engineering observation is recommended to determine the type and extent of preventative maintenance. Earthwork General Considerations The following presents recommendations for site preparation, excavation, subgrade preparation and placement of engineered fills on the project. All earthwork on the project should be observed and evaluated by Terracon. The evaluation of earthwork should include observation and testing of engineered fill, subgrade preparation, foundation bearing soils, and other geotechnical conditions exposed during the construction of the project. Site Preparation Strip and remove existing fill, debris, and other deleterious materials from proposed building and pavement areas. All exposed surfaces should be free of mounds and depressions that could prevent uniform compaction. The site should be initially graded to create a relatively level surface to receive fill, and to provide for a relatively uniform thickness of fill beneath proposed building structures. 13 Geotechnical Engineering Report Terracon Pinnacle P.U.D. — Townhomes Project No. 20015202 Each alternative should be investigated with respect to current material availability and economic conditions. Rigid concrete pavement, a minimum of 6 inches in thickness, is recommended at the locations of dumpsters where trash trucks park and load. Aggregate base course (if used on the site) should consist of a blend of sand and gravel, which meets strict specifications for quality and gradation. Use of materials meeting Colorado Department of Transportation (CDOT) Class 5 or 6 specifications is recommended for base course. Aggregate base course should be placed in lifts not exceeding six inches and should be compacted to a minimum of 95% Standard Proctor Density (ASTM D698). Asphalt concrete should be composed of a mixture of aggregate, filler and additives, if . required, and approved bituminous material. The asphalt concrete surface materials should conform to approved mix designs stating the Superpave properties, optimum asphalt content, job mix formula and recommended mixing and placing temperatures. Aggregate meeting Colorado Department of Transportation Grading S, SX or SG specifications is recommended for all asphalt concrete surface materials. Mix designs should be submitted prior to.construction to verify their adequacy. Asphalt material should be placed in maximum 3-inch lifts and should be compacted to a minimum of 92 to 96% of Maximum Theoretical Density (ASTM D2041). Where rigid pavements are used, the concrete should be obtained from an approved mix design with the following minimum properties: • Compressive Strength @ 28 days.............................................4000 psi minimum • Strength Requirements.........................................................................ASTM C94 • Minimum Cement Content........................................................... 6.5 sacks/cu. yd. • Cement Type..................................................................................Type I Portland • Entrained Air Content.................................................................................6 to 8% • Concrete Aggregate........................................ASTM C33 and CDOT Section 703 AggregateSize.............................................................................1 inch maximum • Maximum Water Content.........................................................0.49 lb/lb of cement • Maximum Allowable Slump........................................................................4 inches Concrete should be deposited by truck mixers or agitators and placed a maximum of 90 minutes from the time the water is added to the mix. Other specifications outlined by the Colorado Department of Transportation should be followed. 12 Geotechnical Engineering Report Pinnacle P.U.D. — Townhomes Project No. 20015202 Terracon Terracon estimated traffic criteria for pavement thickness design including the projected 20- year average daily traffic or volume, and approximate percentage of trucks. From these estimated or assumed values, Terracon computed the 18-kip equivalent single axle load (ESAL) at 51,100 for light traffic paved areas and 146,000 for. heavy volume or truck access/drive areas. Local drainage characteristics of proposed pavement areas are considered to vary from fair to good depending upon location on the site. For purposes of this design analysis, fair drainage characteristics are considered to control the design. These characteristics, coupled with the approximate duration of saturated subgrade conditions, results in a design drainage coefficient of 1.0 when applying the AASHTO criteria for design. For flexible pavement design, a terminal serviceability index of 2.0 was utilized along with inherent reliability of 75% and a design life of 20 years. Using the correlated design R-value of 10, appropriate ESAL/day, environmental criteria and other factors, the structural numbers (SN) of the pavement sections were determined on the basis of the 1993 AASHTO design equation. In addition to the flexible pavement design analyses, a rigid pavement design analysis was completed, based upon AASHTO design procedures. Rigid pavement design is based on an evaluation of the Modulus of Subgrade Reaction of the soils (K-value); the Modulus of Rupture of the concrete, and other factors previously outlined. The design K-value of 100 for the subgrade soils was determined by correlation to the laboratory tests results. A modulus of rupture of 600 psi (working stress 450 psi) was used for pavement concrete. The rigid pavement thicknesses for each traffic category were determined on the basis of the AASHTO design equation. Recommended alternatives for flexible and rigid pavements, summarized for each traffic area, are as follows: Recommended Pavern nE Thickness (Inches} Asphalt AsphaltCoricrete Aggregate Concrete, Portland c Trafiic:Area Alternatnre ,.. Base Surface Cement ;Total = ,:Surface ..:Grading S or 5x Con(se Gra. jog 5 or Concrete j .... , Automobile A 3.0 6.0 9.0 Parking B 2.5 3.0 5.50 Areas C 5.0 5.0 Truck A 3.5 7.0 10.5 Access Drive B 3.0 3.0 6.0 Areas c 6.0 6.0 11 Geotechnical Engineering Report Terracon Pinnacle P.U.D. — Townhomes Project No. 20015202 subsurface materials, a soil profile type S., should be used for the design of structures for the proposed project (1997 Uniform Building Code, Table No. 16-J). Floor Slab Design and Construction Some differential movement of a slab -on -grade floor system is possible should the subgrade soils become elevated in moisture content. To reduce potential slab movements, the subgrade soils should be prepared as outlined in the earthwork section of this report. For structural design of concrete slabs -on -grade, a modulus of subgrade reaction of 100 pounds per cubic inch (pci) may be used for floors supported on existing soils. Additional floor slab design and construction recommendations are as follows: • Positive separations and/or isolation joints should be provided between slabs and all foundations, columns or utility lines to allow independent movement. • Control joints should be provided in slabs to control the location and extent of cracking. • Interior trench backfill placed beneath slabs should be compacted in accordance with recommended specifications outlined below. • A minimum 8-inch layer of free -draining gravel should be placed beneath basement floor slabs in conjunction with the underslab drainage system. • In areas subjected to normal loading, a minimum 4-inch layer of clean -graded gravel should be placed beneath interior slabs. • Floor slabs should not be constructed on frozen subgrade. • Other design and construction considerations, as outlined in the ACI Design Manual, Section 302.1 R are recommended. Pavement Design and Construction —for On -Site Parking Areas Design of pavements for the on -site private pavement areas, (i.e. City of Fort Collins' non - jurisdictional roadways) have been based on the procedures outlined in the 1993 Guideline for Design of Pavement Structures by the American Association of State Highway and Transportation Officials (AASHTO). Areas within proposed pavements on the site will be divided into categories based upon anticipated traffic and usage. 10 Geotechnical Engineering Report Pinnacle P.U.D. — Townhomes Project No. 20015202 Terracon into the roadway underdrain system, then empty into spring creek or discharge into an approved area. Authorization may be required by the City of Fort Collins -Storm Water Division as to the desired point of discharge. Others are providing final design parameters and details. Lateral Earth Pressures For soils above any free water surface, recommended equivalent fluid pressures for unrestrained foundation elements are: • Active: Cohesive soil backfill (on -site clay)........................................45 psf/ft Cohesionless soil backfill (on -site sand)................................35 psf/ft • Passive: Cohesive soil backfill (on -site clay) .......................... :........... 250 psf/ft Cohesionless soil backfill (on -site sand)..............................350 psf/ft • Adhesion at Base of Footings.................................................500 psf Where the design includes restrained elements, the following equivalent fluid pressures are recommended: • At rest: Cohesive soil backfill (on -site clay)........................................60 psf/ft Cohesionless soil backfill (on -site sand) ................................ 50 psf/ft The lateral earth pressures herein do not include any factor of safety and are not applicable for submerged soils/hydrostatic loading. Additional recommendations may be necessary if submerged conditions are to be included in the design. Fill against grade beams and retaining walls should be compacted to densities specified in Earthwork. Compaction of each lift adjacent to walls should be accomplished with hand - operated tampers or other lightweight compactors. Overcompaction may cause excessive lateral earth pressures, which could result in wall movement. Seismic Considerations The project site is located in Seismic Risk Zone I of the Seismic Zone Map of the United States as indicated by the 1997 Uniform Building Code. Based upon the nature of the M Geotechnical Engineering Report Terracon Pinnacle P.U.D. — Townhomes Project No. 20015202 Foundation walls should be reinforced as necessary to reduce the potential for distress caused by differential foundation movement. The use of joints at openings or other discontinuities in masonry walls is recommended. Foundation excavations should be observed by the geotechnical engineer. If the soil conditions encountered differ significantly from those presented in this report, supplemental recommendations will be required. Basement Construction Groundwater was encountered on the site at approximate depths of 5 to 7-feet below existing grades. Full -depth and/or garden -level basement construction is considered feasible for the majority of the site provided that basement slabs are placed a minimum of 4- feet above the groundwater level and/or installation of an underdrain system in conjunction with interior perimeter drainage systems for each unit are installed. To reduce the potential for groundwater to enter basements, installation of dewatering systems is recommended. The dewatering systems should, at a minimum, include an :underslab gravel drainage layer sloped to an interior perimeter drainage system. The drainage systems should consist of a properly sized perforated pipe, embedded in free - draining gravel, placed in a trench at least 12-inches in width. The trench should be inset from the interior edge of the nearest foundation a minimum of 12-inches. In addition, the trench should be located such that an imaginary line extending downward at a 45-degree angle from the foundation does not intersect the nearest edge of the trench. Gravel should extend a minimum of 3-inches beneath the bottom of the pipe. The drainage system should be sloped at a minimum 1/8 inch per foot to a suitable outlet, such as a sump and pump system. The underslab drainage layer should consist of a minimum 6-inch thickness of free -draining gravel meeting the specifications of ASTM C33, Size No. 57 or 67. Cross -connecting drainage pipes should be provided beneath the slab at 15 intervals, and should discharge to the perimeter drainage system. In an effort to lower groundwater levels throughout the site to allow for lower level construction, it is recommended an area underdrain system be installed. The area underdrain system should be placed in the sewer line utility trench and day light/gravity flow to the south toward spring creek. The individual units' interior perimeter drainage systems should be connected to the roadway underdrain system. Terracon recommends each individual unit have its own sump pit and sump pump, and then be connected to a single collection line from the entire complex which would then discharge 8 Geotechnical Engineering Report Terracon Pinnacle P.U.D. — Townhomes Project No. 20015202 • spread footings and/or grade beams bearing on undisturbed soils or structural fill. Slab -on -grade construction is considered acceptable for use, provided that design and construction recommendations are followed and an interior perimeter drainage system is installed. Foundation Systems Due to the presence of low swelling subsurface soils on the site, spread footing foundations bearing upon undisturbed subsoils and/or engineered fill are recommended for support for the proposed structures. The footings may be designed for a maximum bearing pressure of' 1500 psf. In addition, the footings should be sized to maintain a minimum dead -load pressure of 500 psf. The design bearing pressure applies to dead loads plus design live load conditions. The design bearing pressure may be increased by one-third when considering total loads that include wind or seismic conditions. It is recommended the bottom of the footings be placed a minimum of 3-feet above the groundwater level and an interior perimeter drains are installed and connected to- the subsurface underdrain system. To achieve this requirement in areas where groundwater was encountered_ at relatively shallow depths, it may be necessary to place engineered fill material to raise site grades as well as the installation of an area underdrain system. Based on our review of the proposed civil engineering drawings prepared by Shear Engineering Corporation, the proposed top of wall (T.O.W.) elevations vary from 4961 at the northwest corner and drop to approximately 4956 at the southeast corner. Assuming the basement footings will be placed approximately 8 to 9-feet below T.O.W. elevations, and correlating with the groundwater piezometric surface flow.diagram, Figure 3, the footings would be approximately 1-1/2 to 2-1/2 feet above existing water levels. Exterior footings should be placed a minimum of 30 inches below finished grade for'frost protection and to provide confinement for the bearing soils. Finished grade is the lowest adjacent grade for perimeter footings. Footings should be proportioned to reduce differential foundation movement. Proportioning on the basis of equal total settlement is recommended; however, proportioning to relative constant dead -load pressure will also reduce differential settlement between adjacent footings. Total settlement resulting from the assumed structural loads is estimated to be on the order of 1 inch or less. Additional foundation movements could occur if water from any source infiltrates the foundation soils; therefore, proper drainage should be provided in the final design and during construction. 7 Geotechnical Engineering Report Pinnacle P.U.D. — Townhomes Project No. 20015202 Groundwater Conditions Terracon In the previously drilled test borings in 1985, groundwater was encountered at approximate depths of 1-1/2 to 5-feet below the surface. In the recently drilled 5 additional test borings/piezometers, groundwater was encountered at approximate depths of 5 to 7-1/2-feet below existing site grades. Piezometers were installed to obtain stabilized groundwater elevations and to allow for future groundwater level measurements. These observations represent groundwater conditions at the time of the field exploration, and may not be indicative of other times, or at other locations. Groundwater levels can be expected to fluctuate with varying seasonal and weather conditions, as well as volume of Spring Creek. The following table provides the ground surface, top of casing elevations and the stabilized groundwater levels obtained from each piezometer as measured on October 3, 2001. Test Borg rApproximatez9 M SFr , mar Approximater��� " G outd ater rF q '° ' ,`._ z Gr9gndwater�Pt Ka a sir sEimated .x k` PiezometeryNo'� x �� r 3 s" a TSnrtace; �_ . v> y s v Elevation E s Top Of Eas g s?Surement; r, yA �� Etevaor�fromaTxO #ro[rtaGio�incia Measurement _ r "� x Groundwater . ra;'ro.: ;, � 1 �u �•« a�,�a,x.,. ,t =.�.,...� .Suriace��:� C ��Eleuatcon 1 4956.4 4959.1 :� 9.8 494937 7.1 2 4953.4 4957.0 7.3 10.8 4946.2 3 4953.3 4956.5 6.8 9.9 4946.6 4 4954.0 4956.9 6.4 9.4 4947.5 5 4951.7 4955.1 5.1 1 8.5 4946.6 The estimated piezometric surface was developed for the site based on the groundwater measurement data collected on October 3, 2001. The groundwater contour map for the site based on the piezometric data is included with this report as Figure 3. The piezometric surface was estimated using linear interpolations between piezometers and was based upon groundwater elevations in each piezometer. As illustrated from Figure 3, the groundwater flow was estimated to be in the east to slightly southeast direction. This tends to follow the gradient of Spring Creek, which borders the southern portion of the site. ENGINEERING ANALYSES AND RECOMMENDATIONS Geotechnical Considerations The site appears suitable for the proposed construction from a geotechnical.engineering point of view. The following foundation systems were evaluated for use on the site: Geotechnical Engineering Report Terracon Pinnacle P.U.D. — Townhomes Project No. 20015202 SUBURFACE CONDITIONS Geology The proposed site is located within the Colorado Piedmont section of the Great Plains physiographic province. The Colorado Piedmont, formed during Late Tertiary and Early quaternary time (approximately two million (2,000,000) years ago), is a broad, erosional trench, which separates the Southern Rocky Mountains from the High Plains. Structurally, the site lies along the western.flank of the Denver Basin. During the Late Mesozoic and Early Cenozoic Periods (approximately seventy million (70,000,000) years ago), intense tectonic activity occurred, causing the uplifting of the Front Range and associated downwarping of the Denver Basin to the east. Relatively flat uplands and broad valleys characterize the present-day topography of the Colorado Piedmont in this region. The site is underlain by the Cretaceous Pierre formation. The Pierre shale underlies the site at approximate depths of 10 to 13-feet below the surface. The Pierre shale is overlain by alluvial sands and clays of Pleistocene and/or Recent Age. Soil Conditions The subsoils at the site consisted of sandy lean clay, silty clayey sand and silty sand with gravel extending to the bedrock below. Siltstone/sandstone bedrock was encountered in each of the 5 additional test borings at approximate depths of 10 to 13-feet below existing site grades and extended to the depths explored. These soil conditions are relatively consistent with those encountered during the 1985 geotechnical engineering exploration at the site. Field and Laboratory Test Results Field and laboratory test results indicate the clay soils are medium stiff to very stiff in consistency, exhibits low to moderate swell potential, and moderate load bearing characteristics. The sand and gravel stratum is medium dense to dense in relative density and exhibits moderate bearing characteristics. The bedrock stratum is moderately hard to hard with increased depths and exhibits moderate swell potential and moderate to high bearing characteristics. The stratification boundaries shown on the enclosed boring logs represent the approximate locations of changes in soil types; in -situ, the transition of materials may be gradual. The soil profile for this portion of the site is generally consistent with the soil conditions presented in our previous subsurface exploration report. 5 Geotechnical Engineering Report Terracon Pinnacle P.U.D. — Townhomes Project No. 20015202 resistance value is a useful index in estimating the consistency, relative density or hardness of the materials encountered. Groundwater conditions were evaluated in the 5 additional drilled test borings at the time of drilling and when checked 1 day after drilling. Laboratory Testing All samples retrieved during the field exploration were returned to the laboratory for observation by the project geotechnical engineer and were classified in accordance with the Unified Soil Classification System described in Appendix C. Samples of bedrock were classified in accordance with the general notes for Bedrock Classification. At that time, the field descriptions were confirmed or modified as necessary and an applicable laboratory - testing program was formulated to determine engineering properties of the subsurface materials. Boring logs were prepared and are presented in Appendix A. Laboratory tests were conducted on selected soil samples and are presented in Appendix B. The test results were used for the geotechnical engineering analyses, and the development of foundation and earthwork recommendations. All laboratory tests were performed in general accordance with the applicable ASTM, local or other accepted standards. Selected soil and bedrock samples were tested for the following engineering properties: • Water Content Compressive Strength • Dry Density • Plasticity Index • Consolidation • Water Soluble Sulfate Content • Expansion SITE CONDITIONS The site for the proposed construction is located south of East Prospect Road, north of Spring Creek, and west of Lemay Avenue. Existing residential structures are presently located along the northern boundary of the site. South of the existing abandoned houses is an area of open, undeveloped vacant land vegetated with native grasses and weeds. The majority of the site is relatively flat, yet exhibiting positive surface flow in the south direction toward Spring Creek, which meanders along the southern perimeter of the property. Existing single-family residential -type structures border the property to the east and west. 4 Geotechnical Engineering Report Pinnacle P.U.D. — Townhomes Project No. 20015202 Terracon the installation and anticipated flow rates generated from the underdrain system and from standard interior perimeter drainage systems, it is our opinion adjacent property owners will not be adversely affected, and the cone of influence will be minimal, primarily within each of the respective complex footprints. SITE EXPLORATION The scope of the services performed for this project included a site reconnaissance by an. engineering geologist, a subsurface exploration program, laboratory testing and engineering analyses. Field Exploration A total of 5 additional test borings were drilled on September 25, 2001 to approximate depths of 15 to 20-feet below existing site grades at the locations shown on the Site Plan, Figure 1. All of the test borings drilled at the site were advanced with a truck -mounted drilling rig, utilizing 3-1/4-inch diameter hollow -stem augers. At the completion of the drilling operations the test borings were converted to piezometers for purposes of future groundwater monitoring. The piezometers were cased with 2-inch diameter Schedule 40, flush jointed, threaded PVC pipe. The lower 10 to 15-feet of the pipe consisted of a 0.20-inch slotted screen. The piezometers were backfilled with 10-20 silica sand to approximately 2-feet above the top of the well screen and an approximate 1 to 2- foot layer of bentonite clay was placed above the silica sand. The remainder of the groundwater piezometer annuluses was backfilled with auger cuttings. The borings were located in the field by Terracon by measurements from existing site features and/or property lines. Surface elevations were measured by use of an engineer's level and referenced to a temporary benchmark (TBM) as shown on the site plan, Figure 1. The TBM was the rim elevation of the sewer manhole situated on the north side of Spring Creek, having an elevation, provided by Shear Engineering, Inc. of 4952.95. The accuracy of boring locations and elevations should only be assumed to the level implied by the methods used to determine each. Continuous lithologic logs of each boring were recorded by the geotechnical engineer during the drilling operations. At selected intervals, samples of the subsurface materials were taken by means of pushing thin -walled Shelby tubes, or by driving split -spoon samplers. Penetration resistance measurements were obtained by driving the split -spoon into the subsurface materials with a 140-pound hammer falling 30 inches. The penetration Kl Geotechnical Engineering Report Pinnacle P.U.D. — Townhomes Project No. 20015202 PROPOSED CONSTRUCTION Terracon Based on information provided to us by Anchor Development and Shear Engineering, Terracon understands the project site will consist of single townhome residential units constructed throughout the project site along with associated paved parking and City of Fort Collins jurisdictional interior roadways. It is anticipated that maximum wall and column loads will be on the order of 1 to 4 klf and 10 to 75 kips, respectively. This report will provide the appropriate recommendations needed to aid in the design of foundations, parking areas, and the recommended subsurface underdrain system. An additional subsurface exploration will be required for the City of Fort Collins' jurisdictional roadways after sewer lines are installed and the subgrade is at or near "final -rough" subgrade elevations. The primary purpose of this study is to update the original geotechnical engineering report and to drill and install 5 groundwater piezometers in an effort to provide future monitoring of groundwater. This study is to supplement previous work provided at the site and will assist the project design engineer for an underdrain/subsurface drainage system, which will be required if basement construction is planned Larimer County Urban Area Street Standards — Section 5.6.2 (Report Requirements) The site location and project description are as follow: The site is to be developed for proposed single-family attached residential townhome units within the Pinnacle P.U.D., situated south of Prospect Road, north of Spring Creek, and west of Lemay Avenue in Fort Collins, Colorado. The site is bordered along the southern boundary by the Spring Creek. Based on a conversation with the City of Fort Collins, it is our understanding the City of Fort Collins has the water rights jurisdiction for this creek. The groundwater elevations and directional flows are presented on the enclosed Groundwater Contour Map, Figure 3. The groundwater directional flow, as shown on this diagram is in the east to slightly southeast direction. The site's previous usage as we understand was primarily for agricultural/grazing purposes. During irrigation seasons and previous site utilization, groundwater was encountered at shallower depths than recently. Our records indicate groundwater levels in 1985 were measured at approximate depths of 1-1/2 to 3-1/2-feet below the surface. In the recently drilled 5 test borings/piezometers, groundwater was encountered at approximate depths of 5 to 7-feet below existing site grades. Based on the recent groundwater measurements and the designed conceptual project development plan, it is our opinion a subsurface underdrain and/or area drainage system is recommended if basement construction is to be utilized. We also recommend that individual perimeter drainage systems be installed and connected to the underdrain system. Based on 2 GEOTECHNICAL ENGINEERING REPORT PROPOSED PINNACLE TOWNHOMES SOUTH OF PROSPECT ROAD, NORTH OF SPRING CREEK, AND WEST OF LEMAY AVENUE FORT COLLINS, COLORADO TERRACON PROJECT NO. 20015202 OCTOBER 10, 2001 INTRODUCTION This report contains the results of our geotechnical engineering exploration for the proposed Pinnacle Townhome development project to be located south of Prospect Road, north of Spring Creek, and west of Lemay Avenue in Fort Collins, Colorado. The site is located in the Northeast 1/4 of Section 24, Township 7 North, Range 69 West of the 6th Principal Meridian, Larimer County, Colorado. The purpose of these services is to provide information and geotechnical engineering recommendations relative to: • subsurface soil and bedrock conditions • groundwater conditions • foundation design and construction • basement construction • lateral earth pressures • floor slab design and construction • pavement design and construction • earthwork • drainage The recommendations contained in this report are based upon the results of field and laboratory testing, engineering analyses, and experience with similar soil conditions, structures and our understanding of the proposed project. PREVIOUS EXPLORATIONS Empire Laboratories, Inc., Terracon's predecessor, performed a geotechnical engineering explorations for the site in on July 1, and 2, 1985. For further information and findings thereof, please refer to our "Report of a Geotechnical Investigation" dated July 8, 1985, Project No. 6069-85. 1 Geotechnical Engineering Report Pinnacle P.U.D. — Townhomes Project No. 20015202 APPENDIX A Site Plan/Boring Location Diagram Test Borings/Piezometers APPENDIX B Laboratory Test Results Terracon APPENDIX C General Notes Pavement Preventative Maintenance Notes iv TABLE OF CONTENTS Page No. Letterof Transmittal............................................................................................................ i INTRODUCTION.................................................................................................................1 : PREVIOUS EXPLORATIONS...................................................................................:.........1 PROPOSED CONSTRUCTION..........................................................................................2 SITEEXPLORATION ..............................:..........................:................................................3 FieldExploration......................................................................................................3 LaboratoryTesting..................................................................................................4 SITECONDITIONS.............................................................................................................4 Geology................................................................................................................... 5 SoilConditions......................................................................................................... 5 Field and Laboratory Test Results........................................................................... 5 GroundwaterConditions.......................................................................................... 6 ENGINEERING ANALYSES AND RECOMMENDATIONS..................:..............................6 Geotechnical Considerations...................................................................................6 FoundationSystems.........................................:......................................................7 BasementConstruction........................................................................................... 8 Lateral Earth Pressures...........................................................................................9 Seismic Considerations...........................................................................................9 Floor Slab Design and Construction ................................. :...................................... 10 Pavement Design and Construction — for On -Site Parking Areas ...........................10 Earthwork................................................................................................................13 General Considerations...............................................................................13 SitePreparation...........................................................................................13 Subgrade Preparation ............... .............:.............................. ....................... 14 Fill Materials and Placement........................................................................14 Excavation and Trench Construction...........................................................15 Additional Design and Construction Considerations................................................16 Exterior Slab Design and Construction........................................................16 Underground Utility Systems........................................................................16 Corrosion Protection....................................................................................16 Surface Drainage.........................................................................................16 GENERALCOMMENTS.....................................................................................................17 Geotechnical Engineering Report Terracon Pinnacle P.U.D. — Townhomes Project No. 20015202 to 5-1/2-feet below site grades. In an effort to lower groundwater levels throughout the site to allow for lower level construction, it is recommended an area underdrain system be installed. The area underdrain system should be placed in the sewer line utility trench and day light/gravity flow to the south toward Spring Creek. The individual units' interior perimeter drainage systems should be connected to the roadway underdrain system. Based on the type of construction proposed, and the anticipated maximum wall and column loads, it is recommended the proposed townhome structures be supported by conventional -type spread footings bearing on undisturbed subsoils and/or on engineered controlled fill. The footings should be placed a minimum of 3-feet above the maximum anticipated rise in groundwater and interior perimeter drains are installed and connected to the subsurface underdrain system. Based on our review of the proposed civil engineering drawings prepared by Shear Engineering Corporation, the proposed top of wall (T.O.W.) elevations vary from 4961 at the northwest corner and drop to approximately 4956 at the southeast corner. Assuming the basement footings will be placed approximately 8 to 9-feet below T.O.W. elevations, and correlating with the groundwater piezometric surface flour diagram, Figure 3, the footings will be 1-1/2 to 2-1/2 feet above existing water levels. Thus, with this close proximity, we recommend an area/subsurface drainage system be installed. Basement construction is considered feasible throughout the site provided lower level slabs are placed a minimum of 4-feet above the maximum anticipated rise in groundwater and interior perimeters drains are installed as previously stated. Slab -on -grade construction is feasible provided the recommendations set forth in this report are followed. Further details are provided in this report: We appreciate the opportunity to be of service to you on this phase of your project. If you have any questions concerning this report, or if we may be of further service to you, please do not hesitate to contact pis--"�- Sincerely, TE CO ?'_• J 1712 David A. Riche•. Geotechnical E t Manager Reviewed by: Doug J. Jobe, P.E. Office Manger Copies to: Addressee (4) Shear Engineering, Corp. (1): Mr. Brian Shear October 10, 2001 Pinnacle Fort Collins, LLC C/o Anchor Development 1083 Wild Cherry Lane Fort Collins, Colorado 80521 Attn: Mr. Russ Wells Irerracon 301 N. Howes • P.O. Box 503 Fort Collins, Colorado 80521-0503 (970) 484-0359 Fax: (970) 484-0454 Re: Geotechnical Engineering Report Proposed Pinnacle Townhomes South of Prospect Road, North of Spring Creek, and West of Lemay Avenue Fort Collins, Colorado Terracon Project No. 20015202 Terracon has completed a geotechnical engineering exploration for the proposed Pinnacle Townhome development project to be located south of Prospect Road, north of Spring Creek, and west of Lemay Avenue in Fort Collins, Colorado. This study was performed in general accordance with our Proposal No. D2001303 dated September 5, 2001 as well as the City of Fort Collins/Larimer County Urban Area Street Standards design criteria, dated January of 2001. Empire Laboratories, Inc., Terracon's predecessor, performed a geotechnical engineering explorations for the site in on July 1, and 2, 1985. For further information and findings thereof, please refer to our °Report of a Geotechnical Investigation" dated July 8, 1985, Project No. 6069- 85. The primary purpose of this study is to update the original geotechnical engineering report to and drill and install 5 groundwater piezometers in an effort to provide future monitoring of groundwater. This study is to supplement previous work provided at the site and will assist the project design engineer for an underdrain/subsurface drainage system, which may be required if basement construction is planned. The results of our engineering study, including the boring location diagram, laboratory test results, test boring records from the 5-additional test borings/piezometers, and the geotechnical engineering recommendations needed to aid in the design and construction of foundations, basement construction, subsurface drainage systems, pavements and other earth connected phases of this project are attached. The subsoils at the site consisted of sandy lean clay, silty clayey sand and silty sand with gravel extending to the bedrock below. Siltstone/sandstone bedrock was encountered in each of the 5 additional test borings at approximate depths of 10 to 13-feet below _existing site grades and extended to the depths explored. Groundwater was encountered in each of the recently installed piezometers at approximate depths of 5 to 7-1/2-feet below existing site grades. In the previously drilled test borings in July of 1985, groundwater was encountered at approximate depths of 1-1/2 Arizona ■ Arkansas ■ Colorado ■ Georgia ■ Idaho ■ Illinois ■ Iowa ■ Kansas ■ Kentucky ■ Minnesota ■ Missouri Montana ■ Nebraska ■ Nevada ■ New Mexico ■ Oklahoma ■ Tennessee \ Texas 1111 Utah ■ Wisconsin ■ Wyoming Quality Engineering Since 1965 GEOTECHNICAL ENGINEERING REPORT PROPOSED PINNACLE TOWNHOMES SOUTH OF PROSPECT ROAD, NORTH OF SPRING CREEK, AND WEST OF LEMAY AVENUE FORT COLLINS, COLORADO TERRACON PROJECT NO. 20015202 OCTOBER 10, 2001 Prepared for. PINNACLE FORT COLLINS, LLC C/O ANHOR DEVELOPMENT 1083 WILD CHERRY LANE FORT COLLINS, COLORADO 80521 ATTN: MR. RUSS WELLS Prepared by: Terracon 301 North Howes Street Fort Collins, Colorado 80521 Irerrato R PRESSURE, psf Specimen Identification Classification Yc, pcf WC,% • 5 3.Oft SILTY CLAYEY SAND 107 17 Notes: CONSOLIDATION TEST Project: Pinnacle Townhomes Irerracon Site: SW of Prospect and Lemay Fort Collins, Colorado Job M 20015202 Date: 10-10-01