The URL can be used to link to this page

Home My WebLink AboutSTERLING HOUSE - PRELIMINARY/FINAL PUD - 5-97 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT'ik)'.`1 _ h 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 Blow-up Polished Severity Groove Surface or Medium Full -Depth Concrete Patch/ ggreg Aggregate Levels Overlay High Slab Replacement Defined Low Seal Cracks No Medium Full -Depth Comer Break Popouts Severity Levels None High Concrete Patch Defined Low Seal Cracks No Underseal, Divided Severity Seal cracks/joints Slab Medium Slab Pumping Levels and High Replacement Defined Restore Load Transfer Low None Low Seal Cracks Medium Full -Depth Patch Medium Full -Depth Durability Punchout Cracking Concrete High Slab Replacement High Patch Low None Low No Medium Medium Faulting Railroad Crossing Policy for this High High Grind Project Low None Scaling Low None Medium Medium Slab Replacement, Joint ;Map Cracking Seal Reseal Crazing Full -depth Patch, High Joints High or Overlay Low Regrade and No Medium Lane/Shoulder Fill Shoulders Shrinkage Severity None Drop-off to Match Cracks Levels High Lane Height Defined Linear Cracking Low Clean & Low None Longitudinal, Transverse and Medium Seal all Cracks Spalling Medium (Comer) 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 Utility Cuts Replace Patch p Low None Medium Replace Small Patching Patch High lrerracon 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 Patching & utility Cut Patching Medium Full -Depth Asphalt Concrete Patch Medium Full -Depth Asphalt Concrete Patch High High Bleeding Low None Polished Aggregate Low 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 Block Cracking Potholes High All Cracks High Patch Bumps & Sags Low None Railroad Crossing Low No Policy for This Project Medium Shallow AC Patch Medium High Full -Depth Patch High Low None Low None Medium Full -Depth Asphalt Concrete Medium Shallow AC Patch Corrugation Ring High Patch High Full -Depth Patch Low None Low None Medium Shallow AC Patch Medium Mill & Shallow AC Depression Shoving 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 lrerracon Medium Clean & Seal All Cracks High ,:. 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. rerracon 4 I W 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. Colluvium 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 man-made fill) Materials deposited through the action of man prior to exploration of the site. Existing Grade The ground surface at the time of field exploration. rerracon LABORATORY TESTS SIGNIFICANCE AND PURPOSE TEST 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 Used to develop an estimate of both the rate and amount of Foundation Consolidation both differential and total settlement of a structure. Design Used to determine the consolidated drained shear strength of Bearing Capacity, Direct soil or rock. Foundation Design & Shear Slope Stability Dry Used to determine the in -place density of natural, inorganic, Index Property Density fine-grained soils. Soil Behavior Used to measure the expansive potential of fine-grained soil Foundation & Slab Expansion and to 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 Plastic Limit, to characterize the fine-grained fraction of soils, and to Soil Plasticity specify the fine-grained fraction of construction materials. Classification Index Used to determine the capacity of soil or rock to conduct a Groundwater Permeability liquid 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, Pavement R-Value 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 To obtain the approximate compressive strength of soils that Bearing Capacity Unconfined possess sufficient cohesion to permit testing in the Analysis Compression unconfined state. for Foundations Water Used to determine the quantitative amount of water in a soil Index Property Content mass. Soil Behavior Merracon ROCK CLASSIFICATION (Based on ASTM C-294) Metamorphic Rocks Metamorphic rocks form from igneous, sedimentary, or pre-existing metamorphic rocks in response to changes in chemical and physical conditions occurring within the earth's crust after formation of the original rock. The changes may be textural, structural, or mineralogic and may be accompanied by changes in chemical composition. The rocks are dense and may be massive but are more frequently foliated (laminated or layered) and tend to break into platy particles. The mineral composition is very variable depending in part on the degree of metamorphism and in part on the composition of the original rock. Marble A recrystallized medium- to coarse -grained carbonate rock composed of calcite or dolomite, or calcite and dolomite. The original impurities are present in the form of new minerals, such as micas, amphiboles, pyroxenes, and graphite. Metaquartzite A granular rock consisting essentially of recrystallized quartz. Its strength and resistance to weathering derive from the interlocking of the quartz grains. Slate A fine-grained metamorphic rock that is distinctly laminated and tends to split into thin parallel layers. The mineral composition usually cannot be determined with the unaided eye. Schist A highly layered rock tending to split into nearly parallel planes (schistose) in which the grain is coarse enough to permit identification of the principal minerals. Schists are subdivided into varieties on the basis of the most prominent mineral present in addition to quartz or to quartz and feldspars; for instance, mica schist. Greenschist is a green schistose rock whose color is due to abundance of one or more of the green minerals, chlorite or amphibole, and is commonly derived from altered volcanic rock. Gneiss One of the most common metamorphic rocks, usually formed from igneous or sedimentary rocks by a higher degree of metamorphism than the schists. It is characterized by a layered or foliated structure resulting from approximately parallel lenses and bands of platy minerals, usually micas or prisms, usually amphiboles, and of granular minerals, usually quartz and feldspars. All intermediate varieties between gneiss and schist and between gneiss and granite are often found in the same areas in which well-defined gneisses occur. rarracon ROCK CLASSIFICATION (Based on ASTM C-294) Igneous Rocks Igneous rocks are formed by cooling from a molten rock mass (magma). Igneous rocks are divided into two classes (1) plutonic, or intrusive, that have cooled slowly within the earth; and (2) volcanic, or extrusive, that formed from quickly cooled lavas. Plutonic rocks have grain sizes greater than approximately 1 mm, and are classified as coarse- or medium -grained. Volcanic rocks have grain sizes less than approximately 1 mm, and are classified as fine-grained. Volcanic rocks frequently contain glass. Both plutonic and volcanic rocks may consist of porphyries that are characterized by the presence of large mineral grains in a fine-grained or glassy groundmass. This is the result of sharp changes in rate of cooling or other physico-chemical conditions during solidification of the melt. Granite Granite is a medium- to coarse -grained light-colored rock characterized by the presence of potassium feldspar with lesser amounts of plagioclase feldspars and quartz. The characteristic potassium feldspars are othoclase or microcline, or both; the common plagioclase feldspars are albite and oligoclase. Feldspars are more abundant than quartz. Dark -colored mica (biotite) is usually present, and light-colored mica (muscovite) is frequently present. Other dark -colored ferromgnesian minerals, especially hornblende, may be present in amounts less than those of the light-colored constituents. Quartz-Monzonite Rocks similar to granite but contain more plagioclase feldspar than potassium and Grano -Diorite feldspar. Basalt Fine-grained extrusive equivalent of gabbro and diabase. When basalt contains natural glass, the glass is generally lower in silica content than that of the lighter -colored extrusive rocks. erraco 1. I ROCK CLASSIFICATION (Based on ASTM C-294) Sedimentary Rocks Sedimentary rocks are stratified materials laid down by water or wind. The sediments may be composed of particles of pre-existing rocks derived by mechanical weathering, evaporation or by chemical or organic origin. The sediments are usually indurated by cementation or compaction. Chert Very fine-grained siliceous rock composed of micro -crystalline or crypto- crystalline quartz, chalcedony or opal. Chert is various colored, porous to dense, hard and has a conchoidal to splintery fracture. Claystone Fine-grained rock composed of or derived by erosion of silts and clays or any rock containing clay. Soft massive; gray, black, brown, reddish or green and may contain carbonate minerals. Conglomerate Rock consisting of a considerable amount of rounded gravel, sand and cobbles with or without interstitial or cementing material. The cementing or interstitial material may be quartz, opal, calcite, dolomite, clay, iron oxides or other materials. Dolomite A fine-grained carbonate rock consisting of the mineral dolomite (CaMg (CO3)21' May contain noncarbonate impurities such as quartz, chert, clay minerals, organic matter, gypsum and sulfides. Reacts with hydrochloric acid (HCQ. Limestone A fine-grained carbonate rock consisting of the mineral calcite (CaCo). May contain noncarbonate impurities such as quartz, chert, clay minerals, organic matter, gypsum and sulfides. Reacts with hydrochloric acid (HCL). Sandstone Rock consisting of particles of sand with or without interstitial and cementing materials. The cementing or interstitial material may be quartz, opal, calcite, dolomite, clay, iron oxides or other material. Shale Fine-grained rock composed of, or derived by erosion of silts and clays or any rock containing clay. Shale is hard, platy, or fissile may be gray, black, reddish or green and may contain some carbonate minerals (calcareous shale). Siltstone Fine grained rock composed of, or derived by erosion of silts or rock containing silt. Siltstones consist predominantly of silt sized particles (0.0625 to 0.002 mm in diameter) and are intermediate rocks between claystones and sandstones, may be gray, black, brown, reddish or green and may contain carbonate minerals. lrarracon UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests^ Coarse -Grained Gravels more than Clean Gravels Less Cu > 4 and 1 < Cc <3E Soils more than 50% of coarse than 5% fines' — — — 50% retained on fraction retained on No. 200 sieve No. 4 sieve Cu < 4 and/or 1 > Cc > 3E Gravels with Fines c Fines classify as ML or MH more than 12% fines Fines classify as CL or CH Sands 50% or more Clean Sands Less Cu > 6 and 1 < Cc < 3E of coarse fraction than 5% finesE passes No. 4 sieve Cu < 6 and/or 1 > Cc > 3E Sands with Fines Fines classify as ML or MH more than 12% fines" Fine -Grained Soils Silts and Clays 50% or more Liquid limit less passes the than 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 Elf field sample contained cobbles or boulders, or both, add "with cobbles or boulders, or both" to group name. 'Gravels 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 60 50 X 40 O Z 30 Y F U N 20 i la 7 4 0 0 inorganic organic inorganic organic (DJ0)2 •8Cu=D6o1DLo Cc = Dig x D6o Flf soil contains > 15% sand, add "with sand" to group name. 'If 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. Fines Classify as CL or CH PI > 7 and plots on or above "A line' PI < 4 or plots below "A" line' Liquid limit - oven dried < 0.75 Liquid limit - not dried PI plots on or above "A" line PI lots below "A" line Liquid limit - oven dried < 0.75 Liquid limit - not dried matter, 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. 'if 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. oPl < 4 or plots below "A" line. "PI plots on or above "A" line. oPl plots below "A" line. Soil Classification Group1 Group Names GW Well -graded gravel' GP Poorlv graded oravi GM Silty gravel,G,H Far classificotlon of line -grained soils and nn.-grmned banlgn of c Dare.- grain.d .oI. Egmoof ' -line Horizontal al al 4 to LL - 26.5 en nt of o men al - 0.73 (u - zo) v: 0 •P Equation at 'U - line Vertical at , " 16 to PI 7, then P1 0.9 (LL &L • O� MH oR OH CL-ML ML OR OL 10 16 20 30 40 60 60 70 60 90 100 Iic LIQUID LIMIT (LL) GC Clayey gravelF•0N SW Well -graded sand' SP Poorly graded sand' SM Silty sandGAl SC Clayey sand"," CL Lean clay"x.M ML Silt'.LM OL Organic clayK.L•Kel Organic siltK.L.M.o CH Fat clayK,L,M MH Elastic SiltK•L.M OH silt K.L.M,O Berracon DRILLING AND EXPLORATION DRILLING & SAMPLING SYMBOLS: 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 R : Ring Barrel Sampler - 2.42" I.D., 3" O.D. unless otherwise noted. PA : Power Auger FT : Fish Tail Bit HA : Hand Auger RB : Rock Bit DB : Diamond Bit 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 ICU; silty sand, trace gravel, medium dense ISM). CONSISTENCY OF FINE-GRAINED SOILS Unconfined Compressive Strength, Qu, 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 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 PHYSICAL PROPERTIES OF BEDROCK DEGREE OF WEATHERING: Slight Slight decomposition of parent material on joints. May be color change. Moderate Some decomposition and color change throughout. High Rock highly decomposed, may be extremely broken. HARDNESS AND DEGREE OF CEMENTATION: Limestone and Dolomite: Hard Difficult to scratch with knife. Moderately Can be scratched easily with knife, Hard Cannot be scratched with fingernail. Soft Can be scratched with fingernail. Shale, Siltstone and Claystone: Hard Can be scratched easily with knife, cannot be scratched with fingernail. Moderately Can be scratched with fingernail. Hard Soft Can be easily dented but not molded with fingers. Sandstone and Conglomerate. Well Capable of scratching a knife blade. Cemented Cemented Can be scratched with knife. Poorly Can be broken apart easily with fingers. Cemented lferracon SUMMARY OF TEST RESULTS PROJECT NO. 20965182 Boring No. Depth Ft. Moisture % Dry Density (PCF) Compressive Strength (PSF) Swell Pressure (PSF) Soluble Sulfates % pH Liquid Limit % Plasticity Index % Group Index Classification AASHTO USCS % Fines Penetration Blow/In. 1 .5-1.5 20 9/12 3-4 17 106 8700 270 .0034 136 19 10 A-6(10); CL 65 4-5 14 9/12 7-8 21 107 710 8-9 18 16/12 14-15 17 12/12 19-20 20 20/12 2 .5-1.5 19 14/12 3-4 12 107 9930 4-5 12 970 12/12 7-8 13 111 780 8-9 20 8/12 14-15 17 12/12 19-20 21 11/12 3 0-1 16 39 21 15 A-6(15); CL 76 9/12 1-2 12/12 4-5 17 10/12 9-10 20 13/12 -4 S w E L L Y C O 1 N S O L I D A 2 T I O N 3 a 0.1 1 10 APPLIED PRESSURE, TSF Boring and depth (ft.) Classification DD MC% 101 1 3.0 Sandy Lean Clay 112 16 PROJECT Sterling House Assisted Living Center - Rule JOB NO. 20965182 Drive DATE 12/2/96 CONSOLIDATION TEST TERRACON Consultants Westem,Inc. 0.65 0.60 0.55 v O I D R A T I 0.5C O 0.4! 0.4( 0.35 L 0.1 t APPLIED PRESSURE, TSF Boring and depth (ft.) Classification DD MC% 101 1 3.0 Sandy Lean Clay 112 16 I PROJECT Sterling House Assisted Living Center - Rule JOB NO. 20965182 I n,aoa DATE 12/2/96 CONSOLIDATION TEST TERRACON Consultants Westem,Inc. LOG OF BORING No. 3 Page 1 of 1 CLIENT ARCHITECT / ENGINEER BCI Construction SITE Rule Drive PROJECT Fort Collins, Colorado Sterling House Assisted Living Center SAMPLES TESTS \ >- CD J O to N L~L z Y w Z x H DESCRIPTION N z\ � w w w U_(D x x w > cn o zz d U r d U H UWLL Cc F-O >-LL w Approx. Surface Elev.: 96.5 ft. o Z) z u�im z oa �t~na ^^".." 0.5 6" TOPSOIL 96.0 LE N CLAY 2.0 Brown, moist, stiff 94.5 CL 1 SS 12" 9 16 SS 12" 12 SANDY LEAN CLAY WITH GRAVEL Red, moist, stiff CL 2 SS 12" 10 17 5 9.0 87.5 e _ WELL GRADED SAND WITH — SW 3 SS 12' 13 20 - T . - 10.0 GRAVEL 86.5 — 10 Red, moist to wet, medium dense 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 re icon BORING STARTED 11-26-96 9.8'W.D.= 9.3' A B BORING COMPLETED WL RCME-55 FOREMAN6-96 DML WL Water checked 1 day A.B. APPROVED LRS JOB a 20965182 LOG OF BORING No. 2 Page 1 of 1 CLIENT ARCHITECT I ENGINEER BCI Construction SITE Rule Drive PROJECT Fort Collins, Colorado Sterling House Assisted Living Center SAMPLES TESTS M W (a E z W (L w => 0 U M LL Z\ i (A 3 HO w m N D H U) H E >- H w O >_LL o a 0 W LHiCD ZZ O W UMLL � (n (L JU) J U) W WLL w a (L CD 0 J H = (_ w DESCRIPTION Approx. Surface Elev.: 96.0 ft. ., H 2 H d o _j 0 CO W U) U � ^ A ^ 0.5 6" TOPSOIL 95.5 1.5 LEAN CLAY 94.5 Brown, moist, stiff CL 1 SS 12" 14 19 SANDY LEAN CLAY WITH GRAVEL Red, moist, CL 2 ST 12" 12 107 9930 Stiff to hard 970 3 SS 12" 12 12 5 4 ST 12" 13 111 780 8.5 87.5 5 SS 12" 8 20 - WELL GRADED SAND WITH = _ GRAVEL Q - - _ — Red, moist to wet, 10 Loose to medium dense m SW 6 SS 12" 12 17 15 - 7 SS 12" 11 21 - - 20.0 76.0 20 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 1 �rracon BORING STARTED 11-26-96 WL 9 9.8' W.D. = 9.41 A.B. BORING COMPLETED 11-26-96 : RIG CME-55 FOREMAN DML Water checked 1 day A.B. APPROVED LRS JOB # 20965182 LOG OF BORING No. 1 page 1 of 1 CLIENT BCI Construction ARCHITECT I ENGINEER SITE Rule Drive Fort Collins, Colorado PROJECT Sterling House Assisted Living Center LD O J H x (L Q DESCRIPTION Approx. Surface Elev.: 98.0 ft. F- U_ x F- d o J O (n E w (A U � SAMPLES TESTS 0 W m z W (L >- LU > O U � F- LL z\ I (n 3 F-O (n m \ W F W H z Y F- H Ln w o >_LL M a O W z 2 LL( z z O W UQ�LL (n a. W _j(n J (n WWLL (n a (L ^ " 0.5 6" TOPSOIL 97.5 LEAN AN_E CLAY 2.0 Brown, moist, stiff 96.0 5 10 15 20 CL 1 SS 12" 9 20 270 SANDY LEAN CLAY WITH GRAVEL Red, moist, Stiff to hard 8.5 89.5 CL 2 ST 12" 17 106 8700 3 SS 12" 9 14 4 ST 12" 21 107 710 5 SS 12" 16 18 _ _ _ WELL GRADED SAND WITH GRAVEL = Red, moist to wet, medium dense a 19.0 79.0 SW 6 SS 12" 12 17 WEATHERED 20.0 STT T TON / AY TONE 78.0 7 SS 12" 20 20 Tan to gray, moist, soft --------------------------- 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 Arerracon BORING STARTED 11-26-96 W- Q 10.$' W.D. 9'81 A BORING COMPLETED 11-26-96 WL RIG CME-55 FOREMAN DML WL Water checked 1 day A.B. APPROVED LRS JOB a 20965182 No.1 TBM = NORTHEAST BONNET BOLT OF FIRE HYDRANT ELEV. = 100.0 RULE DRIVE FIGURE 1: SITE PLAN STERLING HOUSE ASSISTED LIVING CENTER FORT COLLINS, COLORADO TCW INC. PROJECT No. 20965182 I lo.2 N SCALE 1" = 60' 1 rerrac®n CONSULTANTS WESTERN, INC. EMPIRE DIVISION Geotechnical Engineering Exploration BCI Construction Project No. 20965182 GENERAL COMMENTS It is recommended that the Geotechnical Engineer be retained to provide a general review of final design plans and specifications in order to confirm that grading and foundation recommendations have been 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. The Geotechnical Engineer should also be retained to provide services during excavation, grading, foundation and construction phases of the work. Observation of post -tensioned slab and/or 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, including field and laboratory evaluation of fill, backfill, pavement materials, concrete and steel should be performed to determine whether applicable project requirements have been met. It would be logical for Terracon Consultants Western, Inc. to provide these additional services for continuing from design through construction and to determine the 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 re-evaluate 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. 18 Geotechnical Engineering Exploration BCI Construction Project No. 20965182 • exterior slabs be supported on fill with no, or very low expansion potential • strict moisture -density control during placement of subgrade fills • placement of effective control joints on relatively close centers and isolation joints between slabs and other structural elements • provision for adequate drainage in areas adjoining the slabs • use of designs which allow vertical movement between the exterior slabs and adjoining structural elements In those locations where movement of exterior slabs cannot be tolerated or must be held to an absolute minimum, consideration should be given to: • Constructing slabs with a stem or key -edge, a minimum of 6 inches in width and at least 12 inches below grade; • supporting keys or stems on drilled piers; or • providing structural exterior slabs supported on foundations similar to the building. 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. The pipe backfill should be compacted to a minimum of 95 percent of Standard Proctor Density ASTM D698. All underground piping within or near the proposed structure should be designed with flexible couplings, so minor deviations in alignment do not result in breakage or distress. Utility knockouts in grade beams should be oversized to accommodate differential movements. Corrosion Protection Results of soluble sulfate testing indicate that ASTM Type 1-II Portland cement is suitable for all concrete on or below grade. Foundation concrete should be designed in accordance with the provisions of the ACI Design Manual, Section 318, Chapter 4. 17 Geotechnical Engineering Exploration BCI Construction Project No. 20965182 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 5 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. Landscaped irrigation adjacent to the foundation system should be minimized or eliminated. 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 Compacted subgrade or existing clay soils will expand with increasing moisture content; therefore, exterior concrete grade slabs may heave, resulting in cracking or vertical offsets. The potential for damage would be greatest where exterior slabs are constructed adjacent to the building or other structural elements. To reduce the potential for damage, we recommend: 16 Geotechnical Engineering Exploration BCI Construction Project No. 20965182 5. Granular soils should be compacted within a moisture content range of 3 percent below to 3 percent above optimum unless modified by the project geotechnical engineer. Compliance Performance of 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. Excavation and Trench Construction Excavations into the on -site soils will encounter a variety of conditions. Excavations into the clays can be expected to stand on relatively steep temporary slopes during construction. However, caving soils and groundwater 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 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. Drainage Surface Drainage: 1. Positive drainage should be provided during construction and maintained throughout the life of the proposed facility. Infiltration of water into utility or 15 Geotechnical Engineering Exploration BCI Construction Project No. 20965182 Percent fines by weight Gradation (ASTM C136) 611 .......................................................................................................... 100 3".....................................................................................................70-100 No. 4 Sieve........................................................................................50-80 No. 200 Sieve..............................................................................50 (max) Liquid Limit........................................................................35 (max) Plasticity Index..................................................................15 (max) 4. Aggregate base should conform to Colorado Department of Transportation Class 5 or 6 specifications. Placement and Compaction: Place and compact fill in horizontal lifts, using equipment and procedures that will produce recommended moisture contents and densities throughout the lift. 2. No fill should be placed over frozen ground. 3. Materials should be compacted to the following: Material Minimum Percent Compaction (ASTM D698) Subgrade soils beneath fill areas.........................................................................95 On -site soils or approved imported fill: Beneathfoundations...........................................................................95 Beneathslabs.....................................................................................95 Beneathpavements............................................................................95 Utilities.................................................................................................95 Miscellaneous backfill.........................................................................90 4. Clay soils placed around or beneath foundations should be compacted within a moisture content range of optimum to 2 percent above optimum. Clay soils placed beneath pavement should be compacted within a moisture content range of 2 percent below to 2 percent above optimum. 14 Geotechnical Engineering Exploration BCI Construction Project No. 20965182 operations. If it is necessary to dispose of organic materials on -site, they should be placed in non-structural areas and in fill sections not exceeding 5 feet in height. 4. 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 structures. 5. All exposed areas which will receive fill, floor slabs and/or pavement, once properly cleared, should be scarified to a minimum depth of 8 inches, conditioned to near optimum moisture content, and compacted. 6. On -site clay soils in proposed pavement areas may pump or become unstable or unworkable at high water contents. Workability may be improved by scarifying and drying. Overexcavation of wet zones and replacement with granular materials may be necessary. Lightweight excavation equipment may be required to reduce subgrade pumping. Minimizing construction traffic on -site is recommended. Use of lime, fly ash, kiln dust, cement or geotextiles could also be considered as a stabilization technique. Laboratory evaluation is recommended to determine the effect of chemical stabilization on subgrade soils prior to construction. Proof -rolling of the subgrade may be required to determine stability prior to paving. Fill Materials: 1. Clean on -site soils 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 or backfill. 3. Imported soils (if required) should conform to the following or be approved by the Project Geotechnical Engineer: 13 Geotechnical Engineering Exploration BCl Construction Project No. 20965182 • 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 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 D. Prior to implementing any maintenance, additional engineering observation is recommended to determine the type and extent of preventative maintenance. Earthwork Site Clearing and Subgrade Preparation: 1. Strip and remove existing vegetation and other deleterious materials from proposed building and pavement areas. All exposed surfaces should be free of mounds and depressions which could prevent uniform compaction. 2. If unexpected fills or underground facilities are encountered during site clearing, such features should be removed and the excavation thoroughly cleaned prior to backfill placement and/or construction. All excavations should be observed by the geotechnical engineer prior to backfill placement. 3. Stripped materials consisting of vegetation and organic materials should be wasted from the site or used to revegetate exposed slopes after completion of grading 12 Geotechnical Engineering Exploration BCI Construction Project No. 20965182 • Modulus of Rupture @ 28 days ....... :............................................... 650 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 • Aggregate Size..................................................................................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. 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 placed (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 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. 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 can be enhanced by minimizing excess moisture which can reach the subgrade soils. The following recommendations should be considered at minimum: 11 Geotechnical Engineering Exploration BCI Construction Project No. 20965182 Traffic Area is Altemabve Recom.mended"Pavement Thicknesses (Inches) Asphalt'; FAggregate Plant Mixed Portland Total Concrete" I ase,Course Bitum. nous Cement .,;:Surface:::: Base Concrete Automobile A 3 6 9 Parking B 2 3 5 C 5 5 Main Traffic A 3 11 14 Corridors B 2 5 7 C 6 6 Each alternative should be investigated with respect to current material availability and economic conditions. 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 and/or plant -mixed bituminous base course should be composed of a mixture of aggregate, filler and additives, if required, and approved bituminous material. The bituminous base and/or asphalt concrete should conform to approved mix designs stating the Hveem properties, optimum asphalt content, job mix formula and recommended mixing and placing temperatures. Aggregate used in plant -mixed bituminous base course and/or asphalt concrete should meet particular gradations. Material meeting Colorado Department of Transportation Grading C or CX specification is recommended for asphalt concrete. Aggregate meeting Colorado Department of Transportation Grading G or C specifications is recommended for plant -mixed bituminous base course. 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 95% Hveem density (ASTM D1560) (ASTM D1561). Where rigid pavements are used, the concrete should be obtained from an approved mix design with the following minimum properties: 10 Geotechnical Engineering Exploration BCI Construction Project No. 20965182 • Contraction joints should be provided in slabs to control the location and extent of cracking. The American Concrete Institute (ACI) recommends the control joint spacing in feet for nonstructural slabs should be 2 to 3 times the slab thickness in inches in both directions. Sawed or tooled joints should have a minimum depth of 25% of slab thickness plus % inch. • 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 should be placed beneath interior slabs. For heavy loading, reevaluation of slab and/or base course thickness may be required. • 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. 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 or compacted soils at the site. Pavement Design and Construction The required total thickness for the pavement structure is dependent primarily upon the foundation soil or subgrade and upon traffic conditions. Based on the soil conditions encountered at the site, the anticipated type and volume of traffic and using a group index of 15 as the criterion for pavement design, the following minimum pavement thicknesses are recommended: 0 Geotechnical Engineering Exploration BCI Construction Project No. 20965182 Where the design includes restrained elements, the following equivalent fluid pressures are recommended: At rest: Cohesive soil backfill (clay)............................................................................ 60 psf/ft The lateral earth pressures herein are not applicable for submerged soils. Additional recommendations may be necessary if such conditions are to be included in the design. Fill against grade beams and retaining walls should be compacted to densities specified in "Earthwork". Medium to high plasticity clay soils or claystone bedrock should not be used as backfill against retaining walls. 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 1994 Uniform Building Code. Based upon the nature of the subsurface materials, a seismic site coefficient, "s" of 1.0 should be used for the design of structures for the proposed project (1994 Uniform Building Code, Table No. 16-J). Conventional Floor Slab Design and Construction Due to the expansive potential of the natural clay, differential movement of conventional floor slab -on -grade may occur should the clay increase in moisture content. Use of floor systems supported structurally independent of the subgrade is a positive means of eliminating the potentially detrimental effects of floor movement. If the owner selects conventional slab -on -grade construction and is willing to assume the risk of future slab movement and related structural damage, the following recommendations are applicable to all planned slab -on -grade construction: A minimum 2'/z-inch void space should be constructed above or below non -bearing partition walls placed on the floor slab. Special framing details should be provided at door jambs and frames within partition walls to avoid potential distortion. Partition walls should be isolated from suspended ceilings. Positive separations and/or isolation joints should be provided between slabs and all foundations, columns or utility lines to allow independent movement. 19 Geotechnical Engineering Exploration BCI Construction Project No. 20965182 proposed structure. The footings and/or grade beams may be designed for a maximum bearing pressure of 3,000 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. In addition, the footings and/or grade beams should be sized to maintain a minimum dead load pressure of 750 psf. 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. Finished grade is the lowest adjacent grade for perimeter footings and floor level for interior footings. 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 settlement resulting from the assumed structural loads is estimated to be on the order of 3/4 inch. Proper drainage should be provided in the final design and during construction to reduce the settlement potential. Foundations and masonry 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 from those presented in this report, supplemental recommendations will be required. Lateral Earth Pressures For soils above any free water surface, recommended equivalent fluid pressures for unrestrained foundation elements are: • Active: • Cohesive soil backfill (clay)............................................................................ 40 psf/ft • Passive: • Cohesive soil backfill (clay).......................................................................... 360 psf/ft • Adhesion at base of footing...................................................................................... 500 psf 7 Geotechnical Engineering Exploration BCI Construction Project No. 20965182 • Bearing Capacity.................................................................................................... 3000 psf Post -Tensioned Slab Foundation Systems Post -tensioned slab construction can be considered as a foundation system for the project. Post -tensioned slabs should be designed using criteria outlined by the Post -Tensioning Institute based on the following: • Maximum Allowable Bearing Pressure................................................................. 3,000 psf • Edge Moisture Variation Distance, em • Center Lift Condition....................................................................................... 5.5 feet • Edge Lift Condition..........................................................................................2.5 feet • Differential Soil Movement, ym • Center Lift Condition...................................................................................3.6 inches • Edge Lift Condition......................................................................................0.8 inches • Slab-Subgrade friction coefficient, m • on polyethylene sheeting.....................................................................................0.75 • on cohesive soils..................................................................................................2.00 Post -tensioned slabs, thickened or turn -down edges and/or interior beams should be designed and constructed in accordance with the requirements of the Post -Tensioning Institute and the American Concrete Institute. Exterior beams for post -tensioned slabs and turned down edges of reinforced slabs should be placed a minimum of 30 inches below finished grade for frost protection. Finished grade is the lowest adjacent grade for perimeter foundations. Foundation excavations should be observed by the geotechnical engineer. If the soil conditions encountered differ from those presented in this report, supplemental recommendations will be required. Spread Footing and/or Grade Beam Foundation Systems Based on the soil conditions encountered in the test borings, a spread footing and/or grade beam foundation system bearing upon undisturbed subsoils may be used to support the 21982, Design and Construction of Post -Tensioned Siabs-on-Ground, Post -Tensioning Institute, First Edition. J Geotechnical Engineering Exploration BCI Construction Project No. 20965182 Groundwater Conditions Groundwater was encountered at depths of 9.8 to 10.5 feet in the test borings at the time of the field exploration. When checked one day after drilling, groundwater was measured at depths of 9.3 to 9.8 feet. 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 Geotechnical Considerations The site appears suitable for the proposed construction from a geotechnical engineering point of view. Potentially expansive soils will require particular attention during design and construction. It is our understanding a post -tensioned slab foundation system is proposed for the site. The following foundation systems were evaluated for use on the site: • reinforced slab -on -grade; • post -tensioned slab foundation system; and • spread footings and/or grade beams founded on natural clays. Design criteria for alternative foundation systems is subsequently outlined. Use of the alternative foundation systems outlined in this report should be determined prior to construction. Conventional slab -on -grade construction is considered acceptable for use, provided anticipated heave can be accommodated and design and construction recommendations are followed. Given the engineering characteristics of the lean clays, consideration should be given to use of structural floor systems if slab heave is not acceptable. Reinforced Slab -on -Grade Based on the subsurface profile encountered in our borings, the results of laboratory tests and our experience with similar soils, the following design parameters are provided for slab -on - grade utilizing BRAB criteria. • Potential Vertical Rise........................................................................................0.75 inches • Effective PI.......................................................................................................................21 6 a Geotechnical Engineering Exploration BCI Construction Project No. 20965182 Piedmont in this region. The site is underlain by the Cretaceous Pierre Formation. The Pierre shale underlies the site at depths of 19 to approximately 25 feet below the surface. The bedrock is overlain by alluvial sand and clay soils of Pleistocene and/or Recent Age. Mapping completed by the Colorado Geological Survey ('Hart, 1972), indicates the site in an area of "Moderate Swell Potential." Potentially expansive materials mapped in this area include bedrock, weathered bedrock and colluvium (surficial units). Soil and Bedrock Conditions The following describes the characteristics of the primary strata encountered in the test borings in order of increasing depths: Silty Topsoil: A %-foot layer of topsoil was encountered at the surface of the test borings. The topsoil has been penetrated by root growth and organic matter. • Lean Clay: A layer of natural brown lean clay was encountered below the topsoil and extends to depths of 1'/2 to 2 feet. The lean clay is moist and stiff in consistency. Sandy Lean Clay with Gravel: A layer of red sandy lean clay with moderate amounts of gravel was encountered below the upper brown clay layer and extends to depths of 8% to 9 feet. The sandy clay is moist to wet with depth and stiff to hard in consistency. • Well -Graded Sand with Gravel: The granular stratum was encountered below the red clay layer and extends to an underlying bedrock stratum or to the depth explored. The sand with gravel is wet and loose to medium dense in relative density. • Claystone-Siltstone Bedrock: The bedrock stratum was encountered in Boring 1 at a depth of 19 feet and extends to the depth explored. The 1-foot of bedrock encountered is weathered, moist and relatively soft. Field and Laboratory Test Results Field and laboratory test results indicate the clay soils at anticipated foundation bearing depth exhibit low to moderate swell potential and moderate to high bearing characteristics. 1 Hart, Stephen S., 1972, Potentially Swelling Soil and Rock in the front Range Urban Corridor, Colorado, Colorado Geological Survey, Environmental Geology No. 7. 4 Geotechnical Engineering Exploration BCI Construction Project No. 20965182 Unified Soil Classification System described in Appendix C. A sample of bedrock was 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. Selected soil and bedrock samples were tested for the following engineering properties: • Water content 0 Liquid limit • Dry density 0 Plasticity Index • Consolidation 0 Percent fines • Compressive strength a Water soluble sulfate content • Expansion The significance and purpose of each laboratory test is described in Appendix C. Laboratory test results are presented on the boring logs and in Appendix B, and were used for the geotechnical engineering analyses, and the development of foundation, pavement and earthwork recommendations. All laboratory tests were performed in general accordance with the applicable ASTM, local or other accepted standards. SITE CONDITIONS The site is a three -acre lot vegetated with weeds and native grasses. The property is bordered to the north by a church, to the south by Rule Drive, to the east by undeveloped land and to the west by a tennis center. The area exhibits slight surface drainage to the east. SUBSURFACE CONDITIONS Geology The proposed area 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 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 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 57 0. t Geotechnical Engineering Exploration BCI Construction Project No. 20965182 lot is planned south and east of the proposed building. Final site grading plans were not available prior to preparation of this report, however, ground floor level is anticipated to be at or slightly above existing site grade. SITE EXPLORATION The scope of the services performed for this project included site reconnaissance by an engineering geologist, a subsurface exploration program, laboratory testing and engineering analysis. Field Exploration A total of three test borings were drilled on November 26, 1996 to depths of 10 to 20 feet at the locations shown on the Site Plan, Figure 1. Two borings were drilled within the footprint of the proposed building to depths of 20 feet, and one boring was drilled in the area of the proposed parking to a depth of 10 feet. All borings were advanced with a truck -mounted drilling rig, utilizing 4-inch diameter solid stem auger. The borings were located in the field by pacing from the intersection of Rule Drive and Lemay Avenue and the approximate location of the southwest property corner. Elevations were taken at each boring location by measurements with an engineer's level from a temporary bench mark (TBM) shown on the Site Plan. The accuracy of boring locations and elevations should only be assumed to the level implied by the methods used. 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 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 resistance value is a useful index to the consistency, relative density or hardness of the materials encountered. Groundwater measurements were made in each boring at the time of the site exploration, and one 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 i7 GEOTECHNICAL ENGINEERING REPORT STERLING HOUSE ASSISTED LIVING CENTER RULE DRIVE WEST OF LEMAY AVENUE FORT COLLINS, COLORADO Project No. 20965182 December 3,1996 INTRODUCTION This report contains the results of our geotechnical engineering exploration for the proposed Sterling House Assisted Living Center to be located on the north side of Rule Drive approximately 1/10th mile west of Lemay Avenue in southeast Fort Collins, Colorado. The site is located in the Northeast 1/4 of Section 1, Township 6 North, Range 69 West of the 6th Principal Meridian. 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 • lateral earth pressures • 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, our experience with similar soil conditions and structures and our understanding of the proposed project. PROPOSED CONSTRUCTION Based on the information provided, the structure is to be an approximately 30,000 square foot single -story building. The building will have wood frame construction and will be supported by a reinforced slab -on -grade, post -tensioned slab or conventional foundation system. A parking 1 Geotechnical Engineering Exploration BCI Construction Project No. 20965182 TABLE OF CONTENTS (cont'd) APPENDIX A Site Plan and Boring Location Diagram Logs of Borings APPENDIX B Laboratory Test Results APPENDIX C General Notes APPENDIX D Pavement Notes iv TABLE OF CONTENTS Page No. Letterof Transmittal.................................................................................................................. ii INTRODUCTION.................................................................................................................1 PROPOSEDCONSTRUCTION..........................................................................................1 SITEEXPLORATION..........................................................................................................2 FieldExploration.......................................................... :........................................... 2 LaboratoryTesting................................................................................................... 2 SITECONDITIONS.............................................................................................................3 SUBSURFACE CONDITIONS.............................................................................................3 Geology................................................................................................................... 3 Soil and Bedrock Conditions....................................................................................4 Field and Laboratory Test Results........................................................................... 4 GroundwaterConditions.......................................................................................... 5 CONCLUSIONS AND RECOMMENDATIONS.................................................................... 5 Geotechnical Considerations................................................................................... 5 ReinforcedSlab-on-Grade.......................................................................................5 Post -Tensioned Slab Foundation Systems.............................................................. 6 Spread Footing and/or Grade Beam Foundation Systems ....................................... 6 Lateral Earth Pressures........................................................................................... 7 SeismicConsiderations........................................................................................... 8 Conventional Floor Slab Design and Construction................................................... 8 Pavement Design and Construction......................................................................... 9 Earthwork................................................................................................................12 Site Clearing and Subgrade Preparation......................................................12 FillMaterials.................................................................................................13 Placement and Compaction.........................................................................14 Compliance..................................................................................................15 Excavation and Trench Construction............................................................15 Drainage..................................................................................................................15 SurfaceDrainage.........................................................................................15 SubsurfaceDrainage...................................................................................16 Additional Design and Construction Considerations.................................................16 Exterior Slab Design and Construction.........................................................16 Underground Utility Systems........................................................................17 CorrosionProtection....................................................................................17 GENERALCOMMENTS.....................................................................................................18 Geotechnical Engineering Exploration BCI Construction Terracon Project No. 20966182 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 us. Sincerely, TERRACON CONSULTANTS WESTERN, INC. Empire Division Prepared by: 62�wG GLisa R. Schoenfeld, P.E Geotechnical Engineer Copies to: Addressee (6) REGIS"1111% SCHpF��F�Q� 23702 s/OAi Reviewed by, William J. Attwooll, Office Manager RED1,9 December 3, 1996 BCI Construction 453 South Webb Road, Suite 500 Wichita, Kansas 67207 Attn: Mr. Doug Kitterman Re: Geotechnical Engineering Report Sterling House Assisted Living Center Rule Drive West of Lemay Avenue Fort Collins, Colorado Project No. 20965182 Terracon Consultants Western, Inc., Empire Division has completed a geotechnical engineering exploration for the proposed Sterling House Assisted Living Center to be located on the north side of Rule Drive approximately 1/10th mile west of Lemay Avenue in southeast Fort Collins, Colorado. This study was performed in general accordance with our proposal number 2596045 dated September 16, 1996. 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, pavement and other earth connected phases of this project are attached. The subsoils at the site consist of lean clay, sandy lean clay with gravel and well -graded sand with gravel underlain by claystone-siltstone bedrock. The clay soils at anticipated foundation bearing depth have low to moderate expansive potential and exhibit moderate to high bearing characteristics. It is our understanding the structure is to be supported by a reinforced slab -on - grade, post -tensioned slab foundation system or conventional spread footings and/or grade beams. Based on the subsurface soils encountered, it is our opinion that the proposed foundation systems are suitable for the type of construction proposed provided the slab and/or structure can accommodate anticipated heave of the expansive subsoils. Further details are provided in this report. R OFFICERS OF THE CORPORATION INVOLVED AS APPLICANTS OR OWNERS OF THE PLANNED UNIT DEVELOPMENT IN FORT COLLINS, COLORADO Timothy J. Buchanan Chairman of the Board and Chief Executive Officer R. Gail Knott Chief Financial Officer Secretary and Treasurer Steven L. Vick President and Director Michael F. Frey Vice President BCI Construction, Inc. (Wholly owned Subsidiary of the Company) GEOTECHNICAL ENGINEERING REPORT STERLING HOUSE ASSISTED LIVING CENTER RULE DRIVE WEST OF LEMAY AVENUE FORT COLLINS, COLORADO PROJECT NO. 20965182 December 3, 1996 Prepared for. BCI CONSTRUCTION 453 SOUTH WEBB ROAD, SUITE 500 WICHITA, KANSAS 67207 ATTN: MR. DOUG KITTERMAN Prepared by. Terracon Consultants Western, Inc. Empire Division 301 North Howes Street Fort Collins, Colorado 80621 lrerracon