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Home My WebLink AboutEAST DRAKE TERRACE OFFICE PARK PUD FINAL - 58 93A - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT• �rrr► TABLE D2 RECOMMENDED PREVENTATIVE MAINTENANCE POLICY FOR JOINTED CONCRETE PAVEMENTS Distress Distress Recommended Distress Distress Recommended Type Severity Maintenance Type Severity Maintenance Low None No Polished Severity Groove Surface Blow-up Medium Full -Depth A Aggregate Levels or Concrete Patch/ Overlay High Slab Replacement Defined Low Seal Cracks No Comer Bra Popouts Severity Levels None Medium Full -Depth High Concrete Patch Defined Low Seal Cracks No Underseal, Divided Severity Seal cracks/joints Slab Medium Slab Pumping Levels and Replacement Defined Restore Load Transfer High Low None Low Seal Cracks Medium Full -Depth Patch . Medium. Full -Depth DurabilTity Punchout Cracking Concrete High Slab Replacement High Patch Low None Low No Faulting Railroad Crossing Policy for this Medium Medium Grind High High Project Low None Scaling Low None Medium Slab Replacement, JointMedium Map Cradling Seal Crazing Full -depth Patch, High Joints High or Overlay Low Regrade and No Lane/Shoulder Medium Fill Shoulders Shrinkage Severity None Drop-off to Match Cracks Levels High Lane Height Defined Linear Cradling Low Clean & Low None Longitudinal' Transverse and Seal all Cracks Spelling (Comer) Medium Medium Partial -Depth High Full Depth Patch High Diagonal Cracks Concrete Patch Low None Low None Large Patching Spelling and Medium Seal Cracks or (Joint) Medium Partial -Depth Patch High High Reconstruct Joint UbTity Cuts Replace Patch Low None Medium Replace Small Patching Patch Empire Laboratories, Inca High FA Division of The Terracon Comoanies, Inc. TABLE D1 RECOMMENDED PREVENTATIVE MAINTENANCE POLICY FOR ASPHALT CONCRETE PAVEMENTS Distress Distress Recommended Distress Distress Recommended Type Severity Maintenance Type Severity Maintenance Low None Low None Alligator Cracking g Patching & Utw" Cut Patching Medium Full -Depth Asphalt Concrete Patch Medium Full -Depth Asphalt Concrete Patch High High Low None Low Bleeding Polished Aggregate None Medium Surface Sanding Medium High Shallow AC Patch High Fog Seal Low None Low Shallow AC Patch Medium Clean & Seal Medium Full -Depth Asphalt Concrete Mock Cracking potholes High All Cracks High Patch Bumps & Sags Low None Railroad Crossing Low Policy for This Project Medium Shallow AC Patch Medium Medium High Full -Depth Patch High Low None Low None Medium Full -Depth Asphalt Concrete Medium Shallow AC Patch Corrugation Rung High Patch High Full -Depth Patch Low None Low None Depression Medium Shallow AC Patch Shoving Medium Mill & Shallow AC High Full -Depth Patch High Patch Low None Low ' None Medium Seal Cracks Medium Shallow Asphalt Concrete Edge Cracking Slippage Cracking High Full -Depth Patch High Patch Low Clean & Low None Joint Reflection Seal All Cracks Swell Medium Medium Shallow AC Patch High Shallow AC Patch High Full -Depth Patch Low None Low Lane/Shoulder Drop -Off Weathering & Ravelling Fog Seal Medium Regrade Shoulder Medium High High Low None Longitudinal & Transverse Cracking Empire Laboratories, Inc. Medium Clean & Seal High All Cracks A Division of The Terracon Companies, Inc. REPORT TERMINOLOGY (Based 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 the winter 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. Optimum Moisture The water content at which a soil can be compacted to a maximum dry unit Content weight by a given compactive 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. Empire Laboratories, Inc. A Division of The Terracon Companies, Inc. REPORT TERMINOLOGY (Based on ASTM 13653) 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. Coluuvium 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 layer cast 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. ,Empire Laboratories, Inc. A Division of The Terracon Companies, Inc. LABORATORY TESTS SIGNIFICANCE AND PURPOSE TEST SIGNIFICANCE ' . PURPOSE California Used to evaluate the potential strength of subgrade soil, subbase, Pavement Bearing and base course material, including recycled materials for use in Thickness Ratio road and airfield pavements. Design Used to develop an estimate of both the rate and amount of both Foundation Consolidation differential and total settlement of a structure. Design Used to determine the consolidated drained shear strength of soil Bearing Capacity, Direct or rock. Foundation Design & Shear Slope Stability Dry Used to determine the in -place density of natural, inorganic, fine- Index Property Density grained soils. Soil Behavior Used to measure the expansive potential of fine-grained soil and to Foundation & Slab Expansion provide a basis for swell potential classification. Design Used for the quantitative determination of the distribution of Soil Gradation particle sizes in soil. Classification Liquid & Used as an integral part of engineering classification systems to Soil Plastic Limit, characterize the fine-grained fraction of soils, and to specify the Classification Plasticity Index fine-grained fraction of construction materials. Oxidation- Used to determine the tendency of the soil to donate or accept Corrosion Reduction electrons through a change of the oxidation state within the soil. Potential Potendal Used to determine the capacity of soil or rock to conduct a liquid Groundwater Permeability or gas. Flow Analysis Used to determine the degree of acidity or alkalinity of a soil. Corrosion p H Potential Used to indicate the relative ability of a soil medium to carry Corrosion Resistivity electrical currents. Potential Used to evaluate the potential strength of subgrade soil, subbase, Pavement R-Value and base course material, including recycled materials for use in Thickness road and airfield pavements. Design Soluble Used to determine the quantitative amount of soluble sulfates Corrosion Sulphate within a soil mass. Potential Used to determine the quantitative amounts of sulfides within a Corrosion Su/fide Content soil mass. Potential To obtain the approximate compressive strength of soils that Bearing Capacity Unconfined possess sufficient cohesion to permit testing in the unconfined Analysis for Compression state. Foundations Water Used to determine the quantitative amount of water in a soil mass. Index Property Content Soil Behavior Empire Laboratories, Inc. A Division of The Terracon Companies, Inc. I UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory Test' Coarse -Grained Gravels more than Soils more than 50% of coarse 50% retained on fraction retained on No. 200 sieve No. 4 sieve Sands 50% or more of coarse fraction passes No. 4 sieve Fine -Grained Soils Silts and Clays 50% or more Liquid limit less passesthe then 50 No. 200 sieve Silts and Clays Liquid limit 50 or more Highly organic soils Prim ABased on the material passing the 3-in. (75-mm) sieve 'if field sample contained cobbles or boulders, or both, add "with cobbles or boulders, or both" to group name. cGravels with 5 to 12% fines require dual symbols: GW-GM well -graded gravel with silt GW-GC well -graded gravel with clay GP -GM poorly graded gravel with silt GP -GC poorly graded gravel with clay 'Sands with 5 to 12% fines require dual symbols: SW-SM well -graded sand with silt SW -SC well -graded sand with clay SP-SM poorly graded sand with silt SP-SC poorly graded sand with clay so SO v Z 30 U N20 a. 10 7 4 0 0 'Cu=D6o/Di0 Ca' (go)a Dlo x D6o rlf soil contains > 15% sand, add "with sand" to group name. Gif fines classify as CL-ML, use dual symbol GC -GM, or SC-SM. "If fines are organic, add "with organic fines" to group name. 'If soil contains > 15% gravel, add "with gravel" to group name. 'If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. Clean Gravels Less Cu > 4 and 1 < Cc <3E than 5% finesc — — — Cu < 4 and/or 1 > Cc > 3E Gravels with Fines more than 12% fines` Fines classify as ML or MH Fines classify as CL or CH Clean Sands Less Cu > 6 and 1 < Cc < 3E than 5% fines' Cu < 6 and/or 1 > Cc > 3E Sands with Fines Fines classify as ML or MH more than 12% fines° Fines Classify as CL or CH inorganic PI > 7 and plots on or above "A line' PI < 4 or plots below "A" line' organic Liquid limit - oven dried < 0.75 Liquid limit - not dried inorganic PI plots on or above "A" line PI lots below "A" line organic Liquid limit - oven dried < 0.75 Liquid limit - not dried Soil Classification Group Group Name° GW Well -graded gravel` GP Poorly graded grave GM Silty gravel,G,H GC Clayey gravel"," SW Well -graded sand' SP Poorly graded sand' SM Silty sand"' SC Clayey sand"' CL Lean clay"-" OL Organic silty " CH Fat clayK4M MH Elastic Silt"m OH dark in color, and organic odor PT Peat 'if soil contains 15 to 29% plus No. 200, add .with sand" or "with gravel", whichever is predominant. 4f soil contains > 30% plus No. 200 predominantly sand, add "sandy" to group name. MY soil contains > 30% plus No. 200, predominantly gravel, add "gravelly" to group name. "PI > 4 and plots on or above "A" line. GPI < 4 or plots below "A" line. PPI plots on or above "A" line. GPI plots below 'A" line. siitr L4M.n rw emntncnnon .f Iln.-° inM .oft aM nn.-Vym .a `motion of coo.- 6mtma wib \�1 , Em, of P- - im V, /// ont "tt,o Ui 25.5 R �'0.)3 (LLto Equation el V - un. 0� V.rtical vt LL - 11B to R - 7. Nan PI " 0.9 (LL - °) j � 1 / QQ• MH 0R OH ML oR OL 10 16 20 30 40 sa 60 70 m °o too i1c LIQUID LIMIT (LL) Empire Laboratories, Inc. A Division of The Terracon Companies, Inc. 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 DB : 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 #4 to #200 sieve (4.75mm to 0.075mm) Silt or Clay Passing #200 Sieve (0.075mm) Empire Laboratories, Inc. A Division of The Terracon Companies, Inc. SUMMARY OF TEST RESULTS PROJECT NO. 20935258 :. . •Compressive Strength Plasticity ,. In,. % Classification • US CS Resistivity • Penetration : , SUMMARY OF TEST RESULTS PROIFCT NO. 20935258 Boring No. Depth Ft. Moisture % Dry Density (PCF) Compressive Strength (PCF) Swell Pressure (PCF) Soluble Sulfates % pH Liquid Limit % Plasticity Index % Group Index Classification AASHTO USCS Resistivity (OHM- CM) Penetration Blow/In. 1 0.0-1.0 11.9 14/12 1.0-2.0 18/12 3.0-4.0 18.7 97.6 4780 295 32.1 14.3 9.4 A-6(9) CL 4.0-.50 22.4 4/12 7.0-8.0 19.1 97.2 1130 8.0-9.0 22.4 3/12 14.0-15.0 20.1 7/12 2 0.0-1.0 14.8 12/12 1.0-2.0 1 23/12 3.0-4.0 12.2 105.9 4740 635 4.0-5.0 11.7 9/12 5.0-6.0 11/12 7.0-8.0 12.4 103.9 1340 8.0-9.0 17.2 8/12 9.0-10.0 4/12 14.0-15.0 27.1 5/12 3 0.0-1.0 1 13.9 11/12 1.0-2.0 17/12 2.0-3.0 11.8 102.8 5990 605 .0004 3.0-4.0 12.7 11/12 4.0-5.0 8/12 6.0-7.0 12.9 92.7 1710 7.0-8.0 17.2 4/12 660 .65 .64 .63 a H .62 A .61 a .6_ .53 .58 57 CONSOLIDATION TEST PRO. 20935258 670 0 DEPTH: 7.0 DRY DENSITY: 93.3 PCF 0 MOISTURE: 19.2 % 0 0 0 0 0 l I t '. 0..1 0.25 0.5 1.0 5 10 APPLIED PRESSURE -.TSF _ 4.0 J 3 2 .0 CO _ 1 4 -2 .0 H r a .-4.0 H J ,a :z -6 .0 .o U -8 .0 0.1 . v 0.25 0.5 1.0 APPLIED PRESSURE - TSF EMPIRE LABORATORIES INC. 5 10 LOG OF BORING NO. 4 Page 1 of 1 CLIENT ARCHITECT/ENGINEER Murdoff Construction SITE East Drake Terrace Office Park PROJECT Fort Collins, Colorado Seven (7) Multi-FamilyUnits SAMPLES TESTS X W 0 E z W IL F- Y w O U M WW Z� (A 3 F- O Unto X M H (A H E >- (HA w O >-U- ca. 2 2 LLCD Z Z ow U MLL �u~ia W J (A J (A W WLL v3iaa J H = d CD DESCRIPTION Approx. Surface Elev.:102.0ft. - L~L 2 H (L o J to £ y N U � FILL 1 SS 12" 16 7.7 Sandy Lean Clay with Gravel Brown -tan, moist 2 ST 12" 9.2 103 3070 3.5 98.5 3 SS 12" 7 17.6 4 SS 12" SANDY LEAN CLAY 5 PA Red -brown, moist -wet, medium 5 ST 22.3 93 1460 30 SS 12" 6 17.3 PA 10 i 7 SS 12" 4 25.8 15.0 87.0 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 Empire Laboratories BORING STARTED 104-93 WL g None IT 131411 Caved BORING COMPLETED 10-4-93 WI I.Incorporated RIG CME-55 FOREMAN DL Division of Te(racon WL Checked 24 Hrs. A.B. APPROVED DAR JOB N 20935258 LOG OF BORING NO. 3 Page 1 of 1 CLIENT ARCHITECT/ENGINEER Murdoff Construction SITE East Drake Terrace Office Park PROJECT Fort Collins, Colorado Seven (7) Multi-FamilyUnits SAMPLES TESTS W la E z W O. >_ I— w > O U W W F z\ I N 3 FO O.J U) co \ � F (A H O E F}- w ❑ >-L wy ❑O. O U.0 z z ow L)MU. zH(A ❑(na. M Jan J (A WWIL 30!(n (naa O 0 J H 2 O. cc w DESCRIPTION Approx. Surface Elev.: 101.6 ft. .. 2 F O. W ❑ O N (A U W o 0.5 FILL 101.1 Sandy Lean Clay with Gravel rown-tan, moist 1 SS 12" 11 13.9 2 SS 12" 17 605 3 ST 12" 11.8 103 5990 SANDY LEAN CLAY WITH 4 SS 12" 11 12.7 TRACE GRAVEL. 5 SS 12" 8 Red -brown, moist -wet, medium -stiff 5 PA 6 ST 12" 12.9 93 1710 7 SS 12" 4 17.2 PA 10 8 SS 12" 3 21.8 — 15.0 86.6 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 BORING STARTED 10-4-93 Empire Laboratories WL y 1410" = 13'2" Caved BORING COMPLETED 10-4-93 Incorporated WL RIG CME-55 FOREMAN DL Division of Terracon WL Checked 24 Hrs. A.B. APPROVED DAR JOB # 20935258 LOG OF BORING NO. 2 Page 1 of 1 CLIENT ARCHITECT/ENGINEER Murdoff Construction SITE East Drake Terrace Office Park PROJECT Fort Collins, Colorado Seven (7) Multi-FamilyUnits SAMPLES TESTS W W L Z d H r w > V K W Z i fA F-O Nm \ W r F- H E >. U) w O >_LL cm Z 2 U- 0 ZZ ow 7Nd W JfA WWLL Ndd J H _ n' � DESCRIPTION Approx. Surface Elev.: 98.2 ft. r Ui = d O J r M U 7 FILL 1 SS 12" 12 14.8 Sandy Lean Clay with Gravel Brown -tan, moist 2.0 96.2 2 SS 12" 23 PA SANDY LEAN CLAY WITH 635 3 ST 12" 12.2 106 4740 GRAVEL 4 SS 12" 11.7 Tan, moist, stiff 5 PA 5 ST 12" 12.4 104 1340 6 SS 12" 17.2 9.0 89.2 PA 10 SANDY LEAN CLAY = Red -brown, moist -wet, medium 7 SS 12" 5 27.1 15.0 83.2 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 BORING STARTED 104-93 Empire Laboratories WL s 11,9" Caved I= W61t Caved BORING COMPLETED 104-93 Incorporated RIG CME-55 FOREMAN DL Division of Terracon WL Checked 24 Hrs. A.B. APPROVED DAR JOB N 20935258 LOG OF BORING NO. 1 Page 1 of 1 CLIENT ARCHITECT/ENGINEER Murdoff Construction SITE East Drake Terrace Office Park PROJECT ` Fort Collins, Colorado Seven (7) Multi-FamilyUnits SAMPLES TESTS 0! W m E 7 Z W M >- ►- >- w > O U W W LL Z� F m 3 HO n..J man \ W � f- m H O E Y ca w O YLL 0cu o 0- Z 2 LL(D ZZ ow L)WLL ZF-m =3 m a. W � Jm J m W WLL 3n<m man. CD J N = n, W cD DESCRIPTION Approx. Surface Elev.: 98.1 ft. L~L 2 F- (_ W o J 00 r N m U m """"" 0.5 TOPSOIL 97.6 1 SS 12" 14 11.9 2 SS 12" 18 SANDY LEAN CLAY WITH PA GRAVEL — Red -tan, moist -wet, medium 295 3 ST 18.7 98 4780 4 SS 12" 4 22.4 5 PA 5 ST 19.1 97 1130 6 SS 12" 3 22.4 PA 4 10 i 12.5 85.6 WELL GRADED SAND_WITH GRAVEL 15.0 Red, wet, loose 83.1 15 7 SS 12" 7 20.1 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 BORING STARTED 104-93 Empire Laboratories Incorporated R10,11° T 11°011 BORING COMPLETED 10-4-93 rW RIG CME-55 FOREMAN DL Division of Teaacon Checked 24 Hrs. A.B. APPROVED DAR JOB N 20935258 epi'l �1 1 IMM 40.1 0 . * 50r-4 00r4' 1911; ear7.41 I9rlz. p ,K� GOAD Empire Laboratories, Inc. A Division of The Tercacon Companies, Inc. Murdoff Construction ELI Project No. 20935258 The Geotechnical Engineer should also be retained to provide services during excavation, grading, foundation and construction phases of the work.. Observation of footing excavations should be performed prior to placement of reinforcing and concrete to confirm that satisfactory bearing materials are present and is considered a necessary part of continuing geotechnical engineering services for the project. Construction testing of fill placed on the site is considered part of continuing geotechnical engineering service for the project. Field and laboratory testing of concrete and steel should be performed to determine whether applicable requirements have been met. It would be logical for Empire Laboratories, Inc. to provide these services since we are most qualified to determine consistency of field conditions with those data used in our analyses. The analyses and recommendations in this report are based in part upon data obtained from the field exploration. The nature and extent of.variations beyond the location of test borings may not become evident until construction. If variations then appear evident, it may be necessary to reevaluate the recommendations of this report. Our professional services were performed using that degree of care and skill ordinarily exercised, under similar circumstances, by reputable geotechnical engineers practicing in this or similar localities. No warranty, express or implied, is made. We prepared the report as an aid in design of the proposed project. This report is not a bidding document. Any contractor reviewing this report must draw his own conclusions regarding site conditions and specific construction techniques to be used on this project. This report is for the exclusive purpose of providing geotechnical engineering and/or testing information and recommendations. 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. We are available to discuss the scope of such studies with you. 18 Murdoff Construction ELI Project No. 20935258 • Subsurface Drainage: Free -draining, granular soils containing less than five percent fines (by weight) passing a No. 200 sieve should be placed adjacent to walls which retain earth. A drainage system consisting of either weep holes or perforated drain lines (placed near the base of the wall) should be used to intercept and discharge water which would tend to saturate the backfill. Where used, drain lines should be embedded in a uniformly graded filter material and provided with adequate clean -outs for periodic maintenance. An impervious soil should be used in the upper layer of backfill to reduce the potential for water infiltration. 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 • allowing vertical movements in utility connections • 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 318-121. GENERAL COMMENTS It is recommended that the Geotechnical Engineer be retained to provide a general review of final ..design plans and specifications in order that grading and foundation recommendations may be interpreted and implemented. In the event that any changes of the proposed project are planned, the conclusions and recommendations contained in this report should be reviewed and the report modified or supplemented as necessary. 17 Murdoff Construction ELI Project No. 20935258 encountered at the time of construction, we recommend that we be contacted immediately to evaluate the conditions encountered. 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. The contractor shall retain a geotechnical engineer to monitor the soils exposed in excavations and provide engineering services for such slopes. This will provide an opportunity to monitor the soil types encountered and to modify the excavation slopes as necessary. It also offers an opportunity to verify the stability of the excavation slopes during construction. Drainage: • Surface Drainage: 1. Positive drainage should be provided during construction and maintained throughout the life of the proposed structures. Infiltration of water into utility or foundation excavations must be prevented during construction. Planters and other surface features which could retain water in areas adjacent to the building or pavements should be sealed or eliminated. 2. 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 10 percent for at least 10 feet from perimeter walls. Backfill against footings, exterior walls, and in utility and sprinkler line trenches should be well compacted and free of all construction debris to reduce the possibility of moisture infiltration. 3. 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. 4. Sprinkler systems should not be installed within 5 feet of foundation walls. Landscape irrigation adjacent to the foundation system should be minimized or eliminated. 16 Murdoff Construction ELI Project No. 20935258 • Slopes: 1. For permanent slopes in compacted fill areas, recommended maximum configurations for on -site materials are as follows: Material Maximum Slope Horizontal:Vertical Cohesive soils (clays and silts) ................................ 2:1 Cohesionless soils ........................................ 3:1 Bedrock............................................... 2:1 If steeper slopes are required for site development, stability analyses should be completed to design the grading plan. 0 2. The face of all slopes should be compacted to the minimum specification for fill embankments. Alternately, fill slopes can be over -built and trimmed to compacted material. • Compliance: Recommendations for slabs -on -grade, foundations and pavement elements supported on compacted fills or prepared subgrade depend upon compliance with "Earthwork" recommendations. To assess compliance, observation and testing should be performed under the direction of the geotechnical engineer. • Utility Construction: Excavations into the on -site soils will encounter a variety :of conditions. Excavations into the clays and bedrock can be expected to stand on relatively steep temporary slopes during construction. However, caving soils may also be encountered. 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 15 Murdoff Construction ELI Project No. 20935258 4. Aggregate base course for the proposed parking areas associated with the proposed construction should conform to Colorado Department of Transportation Class 5 or 6 specifications. • Placement and Compaction: C 1. Place and compact fill in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift. 2. Uncompacted fill lifts should not exceed 10 inches loose thickness. 3. No fill should be placed over frozen ground. 4. Materials should be compacted to the following: Material Minimum Percent Compaction (ASTM LrE.S. On -site soils: Beneath foundations ....... 95 Beneath slabs ....................................... 95 Beneath pavements .................... 95 Imported fill: Beneath foundations .................................... 9b Beneath slabs ....................................... 95 Beneath pavements ................................... 95. Aggregate base (beneath slabs) ................................ 95 Miscellaneous backfill....................................... 90 5. On -site sandy lean clay subsoils should be compacted within a moisture content range. of optimum moisture to 2 percent above optimum moisture. Imported granular soils should be compacted within a moisture content range of 2 percent below to 2 percent above optimum. 14 Murdoff Construction ELI Project No. 20935258 soils. Lightweight excavation equipment may be required to reduce subgrade pumping. • Pavement Subgrade Preparation: The subgrade beneath the existing on -site fill material should be scarified, moistened as required, and recompacted for a minimum depth of 12 inches prior to placement of fill and pavement materials. • Fill Materials: 1. Clean on -site soils and/or approved imported materials may be used as fill material for the following: • general site grading • exterior slab areas • foundation areas • pavement areas • interior floor slab areas • foundation backfill 2. Frozen soils should not be used as fill and/or backfill material. 3. Imported soils (if required) should be approved by the geotechnical engineer prior to placement at the site: • Gradation (ASTM C136): percent finer by weight 6.. .............................................. 100 3.. ........................................... 70-100 No.4 Sieve ..................................... 50-100 No. 200 Sieve .................................. 15 (max) • Liquid Limit ..................................... 30 (max) • Plasticity Index .................................. 15 (max) • Maximum expansive potential(%)* ........................ 1.5 *Measured on a sample compacted to approximately 95 percent of the ASTM D698 maximum dry density at about 3 percent below optimum water content. The sample is confined under a 100 psf surcharge and submerged. 13 Murdoff Construction ELI Project No. 20935258 placement and/or construction. All excavations should be observed by the geotechnical engineer prior to placement of reinforcement, concrete and backfill. 3. Stripped materials consisting of organic materials should be wasted from the site, or used to revegetate exposed slopes after completion of grading operations. 4. Sloping areas steeper than 2:1 or 3:1 (horizontal:vertical) should be benched to reduce the potential for slippage between existing slopes and fills. Benches should be level and wide enough to accommodate compaction and earth moving equipment. 5. 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 and paved areas. 6. All exposed areas which will receive fill, once properly cleared and benched where necessary, should be scarified to a minimum depth of twelve inches, conditioned to near optimum moisture content, and compacted to densities as specified in the "Placement and Compaction" section of this report. • Excavation: 1. It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment. 2. 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. 3. On -site sandy lean clay with gravel material may pump or become unstable or unworkable at high water contents. Workability may be improved by scarifying and/or drying. Overexcavation of wet zones and replacement with granular materials may be necessary. Use of lime, fly ash kiln dust, cement or geotextiles could also be considered as a stabilization technique. Adequate laboratory testing should be performed prior to use of chemical stabilization to evaluate the strength characteristics and the effects these materials have on the physical properties of the 12 Murdoff Construction ELI Project No. 20935258 Preventive 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 D. Prior to implementing any maintenance, additional engineering observation is recommended to determine the type, and extent of preventative maintenance. Earthwork: • General Considerations: The conclusions contained in this report for the proposed construction are contingent upon compliance with recommendations presented in this section. Although underground facilities such as septic tanks, cesspools, basements, utilities were not observed during site reconnaissance, such features might be encountered during construction. A sandy lean clay fill material was encountered at the surface in the vicinity of test borings 2 and 4 and extends to a depth of two (2) to three and one-half (3'/z) feet below the surface. It is recommended the upper one (1) foot of the fill material encountered at the site beneath building, filled and paved areas be removed and stockpiled for reuse in planted areas or wasted from the site. The remaining fill material encountered below the upper one (1) foot should be removed to the undisturbed natural soils, stockpiled, moisture conditioned and recompacted to the densities as specified in the placement and compaction section of this report. • Site Clearing: 1. Strip and remove existing vegetation, debris, and other deleterious materials from subgrade existing on -site fill and proposed fill material under building filled and paved areas. 2. If unexpected fills or underground facilities are encountered during site clearing, such features should be removed, the excavation thoroughly cleaned prior to backf ill Murdoff Construction ELI Project No. 20935258 Recommended preventative maintenance policies for asphalt and jointed concrete pavements, based upon type and severity of distress, are provided in Appendix D. Prior to implementing any maintenance, additional engineering observation is recommended to determine the type, and extent of preventative maintenance. Future performance of pavements constructed on the clay soils at this site will be dependent upon several factors, including: • Maintaining stable moisture content of the subgrade soils; and, • Providing for a planned program of preventative maintenance. Since the clay soils on the site have shrink/swell characteristics, pavements could crack in the future primarily because of expansion of the soils when subjected to an increase in moisture content to the subgrade. The cracking, while not desirable, does not necessarily constitute structural failure of the pavement. The performance of all pavements, but in particular the recommended asphalt sections, can be enhanced by minimizing excess moisture which can reach the subgrade soils. The following recommendations should be considered at minimum: • Site grading at a minimum 2% grade away from the pavements; • Compaction of any utility trenches for landscaped areas to the same criteria as the pavement subgrade; • Sealing all landscaped areas in, or adjacent to pavements to minimize or prevent moisture migration to subgrade soils; • Placing compacted backfill against the exterior side of curb and gutter; and, • Placing curb, gutter and/or sidewalk directly on subgrade soils without the use of base course materials. 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. 10 Murdoff Construction ELI Project No. 20935258 Future performance of pavements constructed on the clay soils at this site will be dependent upon several factors, including: • Maintaining stable moisture content of the subgrade soils; and, • Providing for a planned program of preventative maintenance. Since the clay soils on the site have shrink/swell characteristics, pavements could crack in the future primarily because of expansion of the soils when subjected to an increase in moisture content to the subgrade. The cracking, while not desirable, does not necessarily constitute structural failure of the pavement. The performance of all pavements, but in particular the recommended asphalt sections, can be enhanced by minimizing excess moisture which can reach the subgrade soils. The following recommendations should be considered at minimum: • Site grading at a minimum 2% grade away from the pavements; • Compaction of any utility trenches for landscaped areas to the same criteria as the pavement subgrade; • Sealing all landscaped areas in, or adjacent to pavements to minimize or prevent moisture migration to subgrade soils; • Placing compacted backfill against the exterior side of curb and gutter; and, • Placing curb, gutter and/or sidewalk directly on subgrade soils without the use of base course materials. 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. Preventive 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. Murdoff Construction ELI Project No. 20935258 All asphalt concrete shall meet local and/or Colorado Department of Transportation Specifications and shall be placed in accordance with these specifications. • Rigid Pavement. 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 soil was determined by correlation to the laboratory test results. A Modulus of Rupture of 650 psi (working stress 488 psi) was used for pavement concrete. The rigid pavement thicknesses for each traffic category were determined on the basis of the AASHTO design equation. Where rigid pavements are used the concrete should be obtained from an approved mix design with the following minimum properties: • Compressive Strength @ 28 days ................... 3750 psi minimum • Modules of Rupture @ 28 days ..................... 650 psi minimum • Strength Requirements ............................... ASTM C-94 • Minimum Cement Content .......................... 5.5 sacks/cu.yd. • Cement Type ................................:... Type I Portland • Entrained Air Content ................................. 6% + 2% • Concrete Aggregate ................ ASTM C-33 and CDOT Section 703 • Aggregate Size ................................. 1 inch maximum • Approximate Water/Cement Ratio ................. 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. Longitudinal and transverse joints should be provided as needed in concrete pavements for expansion/contraction and isolation. The location and extent of joints should be based upon the final pavement geometry and should be spaced (in feet), at roughly twice the slab thickness (in inches), on center in either direction. Sawed joints should be cut within 24- hours of concrete placement, and should be a minimum depth of 25% of slab thickness plus 1 /4 inch. All joints should be sealed to prevent entry of foreign material and dowelled where necessary for load transfer. Where dowels cannot be used at joints accessible to wheel loads, pavement thickness should be increased by 25 percent at the joints and tapered to regular thickness in 5 feet. H. Murdoff Construction ELI Project No. 20935258. Pavement Design and Construction A Flexible Pavement: It is our opinion flexible pavement is suitable for the proposed parking area associated with the construction of the seven (7) multi -family units. The required total thickness for the pavement structure is dependent primarily upon the foundation soil or subgrade and upon traffic conditions based on soil conditions encountered at the site and the type and volume of traffic using a group index of nine (9) as a criteria for pavement design. The following minimum pavement thicknesses should be provided of the pavement structure. Recommended Pavement Section Thickness (Inches) Asphalt Concrete Surface Aggregate Base Course Plant Mix Bituminous BaseCourse Portland Cement Concrete TOTAL Traffic Area Alternative A 2.5 6.0 8.5 Automobile Parking . B 2.0 3.0 5.0 C 5.0 5.0 A 3.0 8.0 11.0 Main Traffic Corridors/Truck B 2.0 4.0 6.0 Access C 6.0 6.0 Subgrade below proposed paved areas should be prepared in accordance with the recommendations discussed in the "Earthwork" section of this report. The surface of the subgrade should be hard, uniform, smooth and true -to -grade. To prevent the growth of weeds, it is suggested all subgrade under parking areas be treated with a soil sterilant. The base course overlying the subgrade should consist of hard, durable, crushed rock or stone and filter and should have a minimum "R" value of 80. The composite base course material should be free from organic matter in lumps or balls of clay and should meet local and/or Colorado Department of Transportation Class 5 or 6 aggregate base course. The base course should be placed on the subgrade at or near optimum moisture and compacted to at least 95% of Standard Proctor Density ASTM D-698-78. It is important the base course be shaped to grade so proper drainage of the parking area is obtained. 7 Murdoff Construction ELI Project No. 20935258 Foundation excavations should be observed by the geotechnical engineer prior to placement of reinforcing and concrete. 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 a depths of ten (10) to thirteen and one-half (13'/2) feet below existing grade elevations. Full -depth basement construction is considered feasible on the site provided that the basement slabs are placed six and one-half (6'/2) to seven (7) feet below existing site grades. Floor Slab Design and Construction: Low to moderate expansive soils will support the floor slab. Some differential movement of a slab -on -grade floor system is possible should the subgrade soils become elevated in moisture content. Such movements are considered within general tolerance for normal slab -on -grade movements. To reduce any potential slab movements, the subgrade soils should be prepared as outlined in the earthwork section of this report. 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. • Contraction joints should be provided in slabs to control the location and extent of cracking. Maximum joint spacing of 15 to 20 feet in each direction is recommended. • Interior trench backfill placed beneath slabs should be compacted in accordance with recommended specifications outlined below. • In areas subjected to normal loading, a minimum 4-inch layer of clean graded gravel or crushed rock devoid of fines should be placed beneath interior slabs. • If moisture sensitive floor coverings are used on interior slabs, consideration should be given to the use of barriers to minimize potential vapor rise through the slab. • 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. Murdoff Construction ELI Project No. 20935258 • conventional -type spread footings bearing on undisturbed soils, and • conventional -type spread footings bearing on engineered fill material. Slab -on -grade construction for the proposed multi -family buildings is considered acceptable for use when subgrade soils consist of the on -site material and/or imported granular fill material approved by the geotechnical engineer provided that the design and construction recommendations discussed in the "Earthwork" section of this report are followed. Site grading for the proposed construction should be completed in accordance with the recommendations discussed in the "Earthwork" section of this report. Foundation Systems: Due to the presence of moderately expansive soils encountered at the site, conventional -type spread footings foundation systems bearing on undisturbed subsoils, recompacted soils and/or engineered fill material is recommended for support of the proposed structures. The footings may be designed for a maximum bearing pressure of 1,500 pounds per square foot (psf). In addition, the footings should be sized to maintain a minimum dead load pressure of 500 psf. It is also recommended that due to the depth of groundwater encountered at the site, that the location of the bottom of the footings should be placed a minimum of 2 feet above the groundwater table. Exterior footings should be placed a minimum of 30 inches below finished grade for frost protection. Interior footings should bear a minimum of 12 inches below finished grade. Existing on -site fill material should not be used for support of foundations without removal and recompaction. Recommendations for the on -site fill material are discussed in the "Earthwork" section of this report. Footings should be proportioned to minimize 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 or differential settlements resulting from the assumed structural loads are estimated to be on the order of % inch or less, provided that foundations are constructed as recommended. 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. All footings, foundation walls, and masonry walls should be reinforced as necessary to reduce the potential for distress caused by differential foundation movements. The use of joints at openings or other discontinuities in masonry walls is recommended. 5 Murdoff Construction ELI Project No. 20935258 2. Silty Topsoil. The area tested in the vicinity of test borings Nos. 1 and 3 is overlain by a six (6) layer of silty topsoil. The topsoil has been penetrated by root growth and organic matter and should not be used as a bearing soil or as a fill and/or backfill material. This material should be stripped and wasted from the site or stockpiled for reuse in planted areas. 3. Sandy Lean Clay with Gravel. This cohesive, red -brown, sandy lean clay with gravel material underlies the topsoil and fill material and extends to the well graded sand with gravel stratum encountered at twelve and one-half (12'/z) feet below the surface in test boring No. 1 or extends beyond the depths explored in test boring Nos. 2, 3 and 4. The lean clay is plastic, contains varying amounts of sand, and exhibits moderate bearing characteristics in its moist, in -situ condition. When wetted, the clay stratum exhibits moderate swell potential and upon loading consolidation occurs. 4. Well Graded Sand with Gravel. This granular stratum was encountered in test boring No. 1 at a depth of twelve and one-half (12'h) feet below the surface and extends beyond the depths explored. The sand with gravel is medium dense to dense and exhibits generally moderate bearing characteristics in its saturated, in -situ condition. Laboratory Test Results: Laboratory test results indicate that the sandy lean clay material have a moderate expansion potential. When water is added to compacted near -surface soils, the materials exhibit moderate expansion potential. Groundwater Conditions: Groundwater was encountered at depths of eleven (11) to fourteen (14) feet below the surface in the test borings at the time of field exploration. When checked 24 hours after drilling, groundwater was measured at depths of eleven (11) to thirteen and one-half (13'/z) feet below the surface. These observations represent only current groundwater conditions, 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. CONCLUSIONS AND RECOMMENDATIONS Site Development Considerations: The site appears suitable for the proposed construction. Because of variations in the engineering properties of the on -site soils, foundation bearing levels, . structural loads, and possible final grades, the following foundation systems were evaluated for use on the site. 4 Murdoff Construction ELI Project No. 20935258 Selected soil samples were tested for the following engineering properties: • Water content • Plasticity • Dry density • Soluble sulphate content • Unconfined Compressive Strength • Consolidation • Expansion The significance and purpose of each laboratory test is described in Appendix C. Laboratory test results are presented in Appendix B, and were used for the geotechnical engineering analyses, and the development of foundation and earthwork recommendations. All laboratory test were performed in general accordance with applicable ASTM, local or other accepted standards. SITE CONDITIONS The site for the proposed seven (7) multi -family unit structures is situate at the northeast corner of East Drake Road and Stover Street. The site is a vacant tract of land vegetated with native grasses and weeds. The site relatively flat'with positive surface drainage in the north direction. An existing asphalt drive divides the property in half (north and south) and runs from Stover Street to the Governor's apartment complex which is situate on the east side of the property. The area is bordered to the north by Marquette Drive with single-family housing located beyond, to the west by Stover Street and to the south by East Drake Road. It was noted during our field exploration an existing manhole is located in the center portion of the site and is situate approximately one (1) to one and one-half (1'/z) feet below ground surface. SUBSURFACE CONDITIONS Soil Conditions: The soil profile at the site consists of strata of materials arranged in different combinations. In order of increasing depths, they are as follows: 1. Fill Material. The area tested in the vicinity of test borings Nos. 2 and 4 is overlain by a' two (2) to three and one-half (3'/2) foot layer of fill material. The fill consists of a mixture j. of sandy lean clay with trace of gravel. It is not known whether the fill material has been uniformly or properly compacted; therefore, it should not be used as a foundation soil in' its in -situ condition. The majority of the fill material at the site is suitable for reuse as fill and/or backfill material providing the design criteria and recommendations set forth in the "Earthwork" section of this report are met. 3 Murdoff Construction ELI Project No. 20935258 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 four (4) test borings were drilled on the site on October 4, 1993 to depths of fifteen (15) feet below the surface at the locations shown on the Site Plan, Figure 1. The test borings were drilled within the footprint of the proposed multi -family unit family structures. The test borings for the proposed parking areas were incorporated with the four (4) test borings drilled for the seven (7) multi -family units. All borings were advanced with a truck - mounted drilling rig, utilizing 4-inch diameter continuous -type power flight auger drills. The location of borings were positioned in the field with reference to the intersection of East Drake Road and Stover Street. Elevations were taken of the ground surface at each boring location by measurements with an engineer's level in reference to a temporary benchmark (TBM) as shown on the Site Plan, Figure 1. 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 engineering geologist 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 taken with each sampling with the split -spoon by driving the sampler with a 140-pound hammer falling 30 inches.. When properly interpreted, the penetration resistance is a useful index to the consistency, relative density or hardness of the materials encountered. Groundwater conditions were evaluated in each test boring at the time of the site exploration, and 24 hours after drilling. Laboratory Testing: All samples retrieved during the field exploration were returned to the laboratory for evaluation by the project geotechnical engineer, and were classified in accordance with the Unified Soil Classification system described in Appendix C. At that time, the field descriptions were confirmed or modified as necessary, final boring logs prepared, and an applicable`"` laboratory testing program was formulated to determine engineering properties of the subsurface r materials. Boring Logs for the project are presented in Appendix A. VA GEOTECHNICAL ENGINEERING REPORT EAST DRAKE TERRACE OFFICE PARK NORTHEAST CORNER OF EAST DRAKE ROAD AND STOVER STREET FORT COLLINS, COLORADO ELI PROJECT NO. 20935258 INTRODUCTION This report contains the results of our geotechnical engineering exploration for the proposed seven (7) multi -family unit structures to be located at the East Drake Terrace Office Park at the northeast corner of East Drake Road and Stover Street in Fort Collins, Colorado. The site is located in the southwest quarter of the southeast quarter 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 conditions • groundwater conditions • foundation design and construction • basement construction • floor slab design and construction • pavement design and construction • earthwork • drainage The conclusions and recommendations contained in this report are based upon the results of field and laboratory testing, engineering analyses, and experience with similar soil and structural conditions. PROPOSED CONSTRUCTION Based on information provided by Mr. Gordon Murdoff of Murdoff Construction, the project_ will consist of seven (7) multi -family units having crawl space and/or full basement construction. Final site grading plans were not available prior to preparation of this report. Ground floor elevation is anticipated at or slightly above existing site grade. Other major site development will the construction of the parking lot and associated driveways for the proposed multi -family units. Murdoff Construction ELI Project No. 20935258 TABLE OF CONTENTS (CONT.) Paae APPENDIX A Site Plan .............................................. Figure No. 1 Logs of Borings .......................................... Al thru A4 APPENDIX B Laboratory Test Data: Consolidation Tests ......................................... 131 Summary of Test Results .................................... B2 APPENDIX C: GENERAL NOTES Drilling & Exploration ............................................ C1 Unified Soil Classification ........................................ C2 Laboratory Testing, Significance and Purpose ........................... C3 ReportTerminology ............................................. C4 APPENDIX D Recommended Preventative Maintenance -Asphalt Concrete Pavements ......... D1 Recommended Preventative Maintenance -Jointed Concrete Pavements ......... D2 r, Murdoff Construction ELI Project No. 20935258 TABLE OF CONTENTS Page No. Letter of Transmittal................................................... i INTRODUCTION..................................................... 1 PROPOSED CONSTRUCTION ........................................... 1 SITE EXPLORATION .................................................. 2 Field Exploration ............................................... 2 Laboratory Testing .............................................. 2 SITE CONDITIONS ................................................... 3 SUBSURFACE CONDITIONS ............................................. 3 Soil Conditions .................................................. 3 Laboratory Test Results .......................................... 4 Groundwater Conditions .......................................... 4 CONCLUSIONS AND RECOMMENDATIONS ................................. 4 Site Development Considerations .................................... 4 Foundation Systems ............................................. 5- Basement Construction ............................................ 6 Floor Slab Design and Construction ..........:....................... 6 Pavement Design and Construction ............................ 7. Flexible Pavement ......................................... 7 Rigid Pavement ........................................... 8 Earthwork................................................... 11 General Considerations ..................................... 11 Site Clearing ............................................ 11 Excavation............................................ 12 Pavement Subgrade Preparation ............................... 13 Fill Materials ............................................ 13 Placement and Compaction .................................. 14 Slopes................................................ 15 Compliance............................................. 15 Utility Construction ....................................... 15 Drainage.................................................... 16 Surface Drainage ......................................... 16 Subsurface Drainage .................. ................... 17 Additional Design and Construction Considerations ...................... 17 Exterior Slab Design and Construction .......................... 17 Corrosion Protection ....................................... 17 . GENERAL COMMENTS .......*....................................... 17 1 Murdoff Construction ELI Project No. 20935258 Other design and construction details, based upon geotechnical conditions, are presented in this report such as basement construction, pavement design and construction, floor slab design and construction, earthwork and drainage. We have appreciated being of service to you in the geotechnical engineering phase of this project, and are prepared to assist you during the construction phases as well. If you have any questions concerning this report or any of our testing, inspection, design and consulting services, please feel free to contact us. Sincerely, EMPIRE LABORATORIES, INC. A Division of The Terraco Companies, Inc. David A. Richer, P.E. Geotechnical Engineer Reviewed by: Chester C. Smith, P.E. Division Manager DAR/CCS/dmf Copies to: Murdoff Construction PH October 13, 1993 Murdoff Construction 1015 South Taft Hill Road Fort Collins, CO 80521 Attn: Mr. Gordon Murdoff Re: Geotechnical Engineering Report, East Drake Terrace Office Park, Northeast Corner of East Drake Road and Stover Street Fort Collins, Colorado ELI Project No. 20935258 Empire Laboratories, Inc. (ELI) has completed a geotechnical engineering exploration for the proposed seven (7) multi -family unit structures to be located at the East Drake Terrace Office Park located at the northeast corner of East Drake Road and Stover Street in Fort Collins, Colorado. The results of our engineering study, including the boring location diagram, laboratory test results, test boring records, and the geotechnical recommendations needed to aid in the design and construction of foundations and other earth connected phases of this project are attached. The subsurface exploration indicated conditions which are typical of soils commonly found in east Fort Collins. The subsurface soils at the site consisted predominately of a sandy lean clay with. gravel material underlain by a silty sand with gravel. The information obtained by the results of our field exploration and laboratory testing completed for this project indicate that the soils at the site have a low to moderate expansive potential as well as a moderate load bearing capability. Based on the geotechnical engineering analyses, subsurface exploration and laboratory test results, it is recommended that the proposed structures be supported on a conventional -type spread footing foundation system. Slab -on -grade may be utilized for the interior floor system provided that care is taken in the placement and compaction of the subgrade soil. Murdoff Construction ELI Project No. 20935258 PROJECT PERFORMANCE EVALUATION Was the work schedule satisfactory? Did project personnel maintain adequate communication during the course of the work? Were the reports easy to follow and understand? Were you satisfied with the technical competence of the personnel assigned to this project? Do you consider the fees for the project compatible with the services provided? How would you rate our overall performance on this project? Additional Comments: Yes No Yes No Yes No Yes No Yes No Excellent Good Satisfactory Poor Evaluation completed by: Title:,, Date: 2 I November 1, 1993 Murdoff Construction 1015 South Taft Hill Road Fort Collins, CO 80521 Attn: Mr. Gordon Murdoff Re: Geotechnical Engineering Report, East Drake Terrace Office Park, Northeast Corner of East Drake Road and Stover Street Fort Collins, Colorado ELI Project No. 20935258 We appreciate being of service to you in the geotechnical engineering phase of this project. We hope the report has satisfactorily fulfilled your design phase requirements as outlined in our initial proposal. If you have any questions concerning our report, please do not hesitate to contact us. We are also prepared to assist you during the construction phases of the project. For assistance concerning our construction phase or our structural phase services, please contact Gary Martinson or Gary Weeks at 484-0359. As a valued client, and in an effort to better serve your needs in the future, we would appreciate your candid evaluation of our work. The attached form, and the enclosed envelope have been provided to assist you in your response. Any additional personal comments would be especially helpful. We value your business and look forward to being your consultant on this and future projects. Thank you for the opportunity to be of service. Sincerely, EMPIRE LABORATORIES, INC. A Division of The Terracon Companies, Inc. Chester C. Smith, P.E. Division Manager CCS/dmf y / 1(t GEOTECHNICAL ENGINEERING REPORT EAST DRAKE TERRACE OFFICE PARK NORTHEAST CORNER OF EAST DRAKE ROAD AND STOVER STREET FORT COLLINS, COLORADO ELI PROJECT NO. 20935258 Prepared for: Murdoff Construction 1015 South Taft Hill Road Fort Collins, CO 80521 Attn: Mr. Gordon Murdoff Empire Laboratories, Inc. A Division of The Terracon Companies, Inc.