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Home My WebLink AboutHEARTHFIRE PUD - RESUBMITTED PRELIMINARY (REMAND FROM CITY COUNCIL) - 31-95C - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORTa� z,+.. iwI«�i iG.iiiFSYBn'Att�""'rs'�:±cm`' ... " • �.:,_ y !r"r t > -ea r, ,(v . i , t�7J � I �., it i '�u v U. i,,', I r •c. �I �,iJiNV � � In � f: �'h �-•_Ti�..�.ii'O^� �"R '_i�� 'A '� R`J�vyW�I�� d,a As tip •-.I i F.'.4-'t�< r'Ni+'e d - .. ?.yN i iF. tAi44?iav�J„�.. n +lift/ K y.. f tin , i 4i i4 }aiC.4:, '�.;. AN - 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. lrerracon 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. 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 lateral to be equivalent to that produced by the against a support presumed 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. Nerracon w 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 as. Flow Analysis Used to determine the degree of acidity or alkalinity of a soil. Corrosion pH 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 J 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 (HCL). Limestone A fine-grained carbonate rock consisting of the mineral calcite (CaCO3). 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. Irerracon V 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% finest — — — 50% retained on fraction retained on Cu < 4 and/or 1 > Cc > 3E No. 200 sieve No. 4 sieve Gravels with Fines c than 12% fines Fines classify as ML or MH more Fines classify as CL or CH Sands 50% or more Clean Sands Less Cu > 6 and 1 < Cc < 3E of coarse fraction than 5% fines! Cu < 6 and/or 1 > Cc > 3E passes No. 4 sieve Sands with Fines Fines classify as ML or MH more than 12% fines° Fines Classify as CL or CH Fine -Grained Soils Silts and Clays inorganic PI > 7 and plots on or above "A line' 50% or more Liquid limit less PI < 4 or plots below "A" line' passes the than 50 No. 200 sieve organic Liquid limit -oven dried --- < 0.75 Liquid limit - not dried Silts and Clays inorganic PI plots on or above "A" line Liquid limit 50 or more PI lots below "A" line organic Liquid limit - oven dried < 0.75 Liquid limit - not dried +' hl I Primarily organic matter, dark in color, and organic odor ig y organic Soils ABased on the material passing the 3-in. (D20) 2 ".'Cu.D6d/DLp (75-mm) sieve tc = °If field sample contained cobbles or D10 X Os6 boulders, or both, add "with cobbles or boulders, or both" to group name. cGravels with 5 to 12% fines require dual `If soil contains > 15% sand, add "with symbols: sand" to group name. GW-GM well -graded gravel with silt °If fines classify as CL-ML, use dual symbol GW-GC well -graded gravel with clay GC -GM, or SC-SM. GP -GM poorly graded gravel with silt "If fines are organic, add "with organic fines" GP -GC poorly graded gravel with clay to group name. 'Sands with 5 to 12% fines require dual 'If soil contains > 15% gravel, add "with symbols: gravel" to group name. SW-SM well -graded sand with silt 'If Atterberg limits plot in shaded area, soil is SW -SC well -graded sand with clay a CL-ML, silty clay. SP-SM poorly graded sand with silt SP-SC poorly graded sand with clay eo 50 a X e0 O z Jo F U_ 20 a to e Group GW GP GM GC SW SIR SM SC CL ML OL CH MH OH Soil Classification Group Name' Well -graded gravel` Poorly graded grave Silty gravel,G,H Clayey gravel'-i Well -graded sand' Poorly graded sand' Silty sand'-"-' Clayey sand°,"' Lean clay'-'-' SIlt6'L,M Organic clay".`M Organic siltK.L.M.° Fat clay" .L•M Elastic Silt`•LM SIItxXAo 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. 'if soil contains > 30% plus No. 200, predominantly gravel, add "gravelly" to group name. "PI > 4 and plots on or above "A" line. °PI < 4 or plots below "A" line. "PI plots on or above "A" line. °PI plots below "A" line. F., 0o,01icollon al H-n.e-)gram.d . end In<eln<e Ire<Ilon el I.rained Equation of line Horienlol of PI "` to LL"25.5 then a " 073 L - 20) O ` � "I0n Vertical at LL "16 to N men N 0.9 (LL .—. ML 0R OL ..---..... CL—ML 0 0 10 16 20 JO <„ .+ 60 20 !0 90 IDO IIC LIQUID LIMIT (I.L) DRILLING AND EXPLORATION 31LLING & SAMPLING SYMBOLS: oS : Split Spoon - 13/e" 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: moulders, cobbles, gravel or sand. Fine Grained Soils have 3s 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 siie. 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, 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 SUMMARY OF TEST RESULTS PROJECT NO. 20955191 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 Resistivity (OHM -CM) Penetration Blow/In. 5 .5-1.5 11 20/12 4-4.5 11 80 50/6 8-8.3 14 50/4 14-14.3 14 1 1 50/4 6 .5-1.5 20 16/12 3-4 17 6/12 7-7.6 17 205 50/8 14-14.5 15 1 50/5 SUMMARY OF TEST RESULTS PROJECT NO. 20955191 Dry Compressive Swell Soluble pH Liquid Plasticity Group Classification AASHTO ion Resistivity PBlowaI (OHM -CM) Boring Depth Moisture % Density Strength Pressure Sulfates Limit Index Index USCS No. Ft. (PCF) (PSF) (PSF) % % % 17/12 1 .5-1.5 16 32 18 8 A-6(8): CL 3-4 8 98 4860 1630 17/12 4-5 9 15/12 7-8 9 20/12 14-15 11 15/12 2 .5-1.5 17 16112 3-4 10 7-8 16 112 4300 4/12 8-9 19 25/12 14-15 22 15/12 3 .5-1.5 9 3-4 10 115 13,580 1000 15/12 4-5 10 8/12 8-9 13 5/12 14-15 25 22/12 4 .5-1.5 17 3-4 9 110 7080 l015 16/12 4-5 9 13/12 7-8 6 8/12 14-15 23 LEGEND 35—hurt Collins loom, 1 to 3 perccut slopes. This ncarl,y level soil is on terraces and fans. This soil has a pcolile sinlilal• to the one described as representative of the series, hot the combined thiclutess of the surface layer and subsoil is about 22 inclies. Included with this soil is nnapping are a few small are:ts of soils thaL :u•c more sloping or less sloping. Also included are some small areas of Stoneham and Kim soils and a few small areas of soils that have a gravelly layer below :t depLh of 40 inches. Runorr is slow, :uul the hazards of wind and water ermion ;u c slight: to moderate. If irril';nlcd, this soil is well suited to corn, sugar hccts, alfallh, h:u.lcy, ;,,,(I clry heats. Under dryl;urd 111:ulagenleni, it is suited to wheal: and barley. It is also well suited to pasl.ure :uul native gl-asses. Capability units lle-1, it'rig;tl.cd, and 1Ve-3, dryland; Loamy Plains range site; windbreak suitability group 1. S I—I�im (Dunn, 3 to 5 perc•cot slopes. This gently sloping soil is on uplands and fans. This soil has a profile similar to the one described as representative of the series, but the surface layer is about 10 inches thick. Inclticled with this soil in mapping are small areas of soils that are more sloping or less sloping and small ;areas of soils (.lint have a surface layer of clay loam. A water table is wiLhin the root zone daring the grow- ing season in a few small areas. Also included are a fety soul(( areas of 1 ort Collins, Stoneham, and '1'heda- lund soils. Runoff is niedium, and the hazard of erosion is mod- erate. If irrigated, this soil is suited to barley, alfalfa, and wheat :old, to it lesser extent, corn and beaus. Under drylaul manag•enicnt it is suited to pasture and native grasses. C;Inability units IIIe-2, irrigated, and IVe-3; dryland r l.ilamy Plitiils range site; windbreak suit- ability group 1. 103—Slonell:un lonm, 5 to 9 percent elopes. This strongly sloping soil is on uplands and high terraces .Ind bcnchcs, m:1ioly neat• the edge. This soil has a pro- lile similar to (:hc one described :Is representative of tine series, but the conlbincel surface layer and subsoil is abouL lO to 12 inches thick. Included with this soil in mapping are small gravel, spots and small areas of soils that are redder and have a surface layer of sandy loam. Also iucludcd are small areas of Fort Collins, Kim, and Larimer soils. Runoff is rapid, and Lhc h:czard of erosion is severe. If irrigaLed, Lhis soil is well suiLed to pasLurc and, to a lesser cxlenL, wheal, harley, and ;lMllf;t. Uncle" dryland management it is suited to pasture or native, grasses. Capability units I\fe-1, irrigated, and VIe-1, dryland; Loamy Plains range site; windbreak suit ability, group 1. rLMrr a C0 CONSULTANTS WESTERN. INC. EMPIRE DIVISION LOG OF BORING No. 6 Page 1 of 1 CLIENT ARCHITECT I ENGINEER Merrick & Company Merrick & Company SITE Douglas Road & County Road 13 PROJECT Larimer County, Colorado Hoffman Subdivision Filing No. 1 SAMPLES TESTS F \ > F CD O r J O J LLLL in z >- W W (HJ) Z S W DESCRIPTION >- Q� z W z Hh M H = 2 U) W � i (n H O ZZ J(OA U) CO W O. 3 V) OW J(n 0_ U K 0_ U Ho H >- LL U W LL W W LL LD Approx. Surface Elev.: 5095.0 ft. W o W o O z } F W M 0_J (n(n O E: WU oa Z)-U) (n(L 3Wf!) U)a.a " " " 0.5 6" TOPSOIL 5094.5 1 SS 12" 16 20 SANDY LEAN CLAY Brown, moist, medium to stiff CL 2 SS 12" 6 17 5 6.0 5089.0 WEATHERED CLAYSTONE/ SANDSTONE 5088.0 Brown, moist 205 17.0 3 SS 8" 50/.7 17 Moderately hard, cemented s C'T AYSTQLIE/SANDSTONE _— Brown, moist, hard, well cemented — 14.5 5080.5 BOTTOM OF BORING 10 4 SS 5" 50/A 15 THE STRATIFICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES BETWEEN SOIL AND ROCK TYPES: IN -SITU, THE TRANSITION MAY BE GRADUAL. WATER LEVEL OBSERVATIONS (1 fie f?t H BORING STARTED 7_6_87 WL Q None W D Y 8.5' A.B. BORING COMPLETED 7.6_87 WL RIG CME_55 FOREMAN LRS wL APPROVED NRS I JOB N 20953191 LOG OF BORING No. 5 Page 1 of 1 CLIENT ARCHITECT / ENGINEER Merrick & Company Merrick & Company SITE Douglas Road & County Road 13 PROJECT Larimer County, Colorado Hoffman Subdivision Filing No. 1 SAMPLES TESTS H \ >- H O LD O J O J LL 00 z W W (n Z S W U DESCRIPTION >- En Of W w Z\ O: z Ld HI— W H = 2 W > i U) F- O Z Z J(n 0_ F- (n CO W O 3 U) O W J U) n_ U z d U F O H >- LL U W LL W W LL. W (n O >_ W dJ O wU ZI-U) :Kw(n Approx. Surface Elev.: 5083.0 ft. o z m Lo co X: o 0- Z) (n n_ (n na o- " " 0.5 6" TO 5082.5 WEATHERED SANDSTONE 1 SS 12" 20 11 Tan, moist, poorly cemented 2.0 5081.0 80 — SANDSTONE 2 SS 6" 501.5 11 Tan, moist, well cemented — 5 — 1 — 3 SS 4" 50/.3 14 14.3 5068.7 10 4 SS 12" 50/.3 14 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 10-31-95 WL• g None W.D. = 6.0' A.B. BORING COMPLETED 10-31-95 WI. RIG CME-55 FOREMAN DML WL APPROVED NRS IJOB# 20955191 LOG OF BORING No. 4 page 1 of 1 ARCHITECT / ENGINEER CLIENT Merrick &Company Merrick & Company SITE Douglas Road & County Road 13 PROJECT Larimer County, Colorado Hoffman Subdivision FilingNoI . TESTS LD O J U I DESCRIPTION H (L 0- Of (DD Approx. Surface Elev.: 5112.0 ft. AIA: 0.5 6" TOPSOIL SANDY LEAN CLAY Brown, dry to moist Stiff to very stiff SAMPLES „ N > _j N K W i (n F=- O ZZ JN F=-- U) m Ld W O U 3 f- O (A H >- LL O W U X LL J (n W W LL 0_ Wo U CD co C3 n a d z H W U) ca E (L m o_ (n I SS 12" 22 17 5111.5 15.0 BOTTONI OF BORING 5 10 15 CL 2 1 ST 12' 3 ISSI 12" 16 9 110 7080 1015 9 4 1 SS 1 12"1 13 1 6 5 l SS 1 12" 1 8 1 23 FBETWEEN FICATION LINES REPRESENT THE APPROXIMATE BOUNDARY LINES IL AND ROCK TYPES: IN -SITU, THE TRANSITION MAY BE GRADUAL. ER LEVEL OBSERVATIONSBOR(NGSTARTED 7-6-87 ne D Y 14.1' A B BORING COMPLETED 7-6-87 1 ■m��® �[G Cly(l;-5J FOREMAN LRS !ter(APPROVED IVR$ 10B # 20955191 LOG OF BORING No. 3 Page I of 1 ARCHITECT / ENGINEER CLIENT Merrick & Company Merrick & Company SITE Douglas Road & County Road 13 PROJECT Larimer County, Colorado Hoffman Subdivision Filing No. I SAMPLES TESTS ~ o Lo o 0 co J LL � z H� M U DESCRIPTION } O M z� 2 W > I U)O F- z Z JOF- a: (L LO to W O 3 (n O W J U)0_ (L U E d U F- O H >_ LL U W LL W W LL. W W 7 >_ W dJ O WL) ZF-(n :Iwu) 0 Approx. Surface Elev.: 5101.5 ft. O o z D (1) co E C3a Etna (nad "^".^". 0.5 6" TOPSOIL 5101.0 1 SS 12" 15 9 SANDY LEAN CLAY Brown, dry to moist, stiff to hard 5 H =1 15 BOTTOM OF BORING CL 2 ST 12" 10 115 13580 1000 10 3 SS 12" 15 SS 1 12" 1 8 1 13 5 1 SS 1 12" 1 5 1 25 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 10-31-95 WL 4 None W D None A B BORING COMPLETED 10-31-95 WL Irerracc)" RIG CME-55 FOREMAN DML WL APPROVED NRS JOB N 20955191 �— LOG OF BORING No. 2 Page 1 of 1 ARCHITECT / ENGINEER CLIENT Merrick & Company Merrick & Company SITE Douglas Road & County Road 13 PROJECT Larimer County, Colorado Hoffman Subdivision FilingNo. 1 SAMPLES TESTS C7 J O F \ } 1- C2 O J LL M z H H DESCRIPTION >>- N of Z\ o z z H x x w > CO OU I (n O F— H U 0- d U d 1— >- LL. M LL W W O } W 0-J O MU ZhU) END Approx. Surface Elev.: 4996.0 ft. Z ~ N0° O°" �No_ ::: 0.5 6" TOPSOIL 4995.5 1 SS 12" IS 17 N' ! sANQy l FAN CLAY Brown, moist, stiff to very stiff JCL 1 2 1 SS 1 12"1 1 5 I 1I 16 I 1112 14300 I 14 SS 12" 4 19 R 10 Sz 13.0 4983 WEATHERED SANDSTONE Tan, moist, poorly cemented 5 1 SS 1 12" 1 25 1 22 15.0 4981.0 115 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 7-6-87 FUZ12 OW D Y 9 7,AB BORING COMPLETED 7-6-87 ferr LRIG CNIE-55 FOREMAN LRS Water checked 10 days A.Il. APPROVED NRS JOB s 20955191 LOG OF BORING No. 1 Page 1 of 1 CLIENT ARCHITECT / ENGINEER Merrick & Company Merrick & Company SITE Douglas Road & County Road 13 PROJECT Larimer County, Colorado Hoffman Subdivision Filing No. 1 SAMPLES TESTS 0 0 o -j L~L co z >- W W N z S � H H DESCRIPTION >- (f) o' z\ W z W HI- W a NJ2 = F- U7 W> ca W O I U) 3 1- UI O zz O W � F- W H O- a. O- W U W E M M >- U W FO O-J H O >-tL ceU UO:LLof zPw F-�\ F-H J LDD Approx. Surface Elev.: 5120.0 ft. O z I- M U)m r- 00- Lna ¢-.1-1 " " "^ 0.5 6" TOPSOIL 5119.5 SANDY LEAN CLAY 1 SS 12" 17 16 SWELL Brown, dry to moist PSF 2 ST 12" 8 98 4860 Stiff to very stiff 1630 32/18/18/ CL 3 SS 12" 17 5 4 SS 12" 15 9 10 5 SS 12" 20 11 15.0 5105.0 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 BORING STARTED 7-6-87 WL Q WD = A.B.ORING COMPLETED 7-6-87 WL1FerrdL"3M0"i21n RIG CME-55 FOREMAN LRS WL Water checked 10 days A.B. APPROVED AIRS JOB A 20955191 �a r-, I L, Co I 103 ... ........ .. . . q,qo , L%h FIGURE 1: SITEA PLAN. DOUGLAS ROAD & COUNTY ROAD 13 FORT COLLINS, COLORADO ELI. PROJECT No. 20955 CN)l Irrrca%mi% go FAR CONSULTANTS WESTERN, INC. EMPIRE DIVISION FIGURE 1: SITE PLAN DOUGLAS ROAD & COUNTY ROAD 13 LARIMER COUNTY, COLORADO ELI. PROJECT No. 20955191 SCALE 1" = 400' 1 reirracon CONSULTANTS WESTERN, INC. EMPIRE DIVISION A pcq�LPS i2oA �P- �):z F�MAT oj 5 FIGURE 1: SITE PLAN DOUGLAS ROAD & COUNTY RO AD 13 LARIMER COUNTY COLORADO ELI. PROJECT No. 20955191 'III, mppm•� SCALE 1" = 400' Irerracon CON8ULTAN-M WESTERN. INC. EMPIRE DAMON Preliminary Geotechnical Engineering Exploration Merrick & Company TCW Project No. 20955191 Terracon conditions encountered at the site, it is recommended that additional test borings be made prior to final design. Samples obtained from the borings should be tested in the laboratory to provide a basis for evaluating subsurface conditions. This report has been prepared for the exclusive use of our client for specific application to the project discussed and has been prepared in accordance with generally accepted geotechnical engineering practices. No warranty, express or implied, is made. This report has been prepared to aid in the evaluation of the property and to assist the architect and/or engineer in the preliminary design of this project. This report is for the exclusive purpose of providing preliminary 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. 0 Preliminary Geotechnical Engineering Exploration Terracon Merrick & Company TCW Project No. 20955191 U, = 15to25xD Where: UP = the uplift force in kips, and D = the pier diameter in feet Basement Construction: Groundwater was encountered on the majority of the site at depths of 6 to 14 feet below existing grade. Full -depth basement construction is considered feasible on the site provided that basement subgrade is a minimum of 3 feet above existing groundwater. Finished basement slabs should be placed a minimum of 3 feet above the bedrock stratum. A complete dewatering system should be provided around the basement area. Perched groundwater may occur at times since the subsurface soils are relatively impermeable and tend to trap water. Completion of site development, including installation of landscaping and irrigation systems, will likely lead to perched groundwater development. To reduce the potential for groundwater to enter the basement of the structure, installation of a dewatering system is recommended. The dewatering system should, at a minimum, include an underslab gravel drainage layer sloped to a perimeter drainage system. Floor Slab Design and Construction: The variability of the existing soils at approximate slab subgrade elevation could result in differential movement of floor slab -on -grade should expansive soils become elevated in moisture content. Use of structural floor systems, structurally supported independent of the subgrade soils, is a positive means of eliminating the potentially detrimental effects of floor movement. • 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. PRELIMINARY GENERAL COMMENTS It should be noted this was a preliminary investigation and the foundation systems recommended in this report are based on preliminary tests. Due to variations in soil 3 Preliminary Geotechnical Engineering Exploration Merrick & Company TCW Project No. 20955191 Terracon 4. On -site clay soils 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. o Fill Materials: 1 . On -site clay soils are suitable for use beneath slabs or as backfill. 2. On -site bedrock materials are not recommended for use beneath structural ares of the site, or as backfill. Should bedrock materials be used for general site grading, placement in fills at non-structural locations on the site is recommended. Foundation Systems: Due to the presence of moderate of high swelling soils on the site, spread footing and/or grade beam foundations bearing upon undisturbed subsoils and/or engineered fill are recommended for support for the proposed structures. Consideration should be given to using drilled pier foundations for structures founded partly on the bedrock stratum and partly in the clay soils. Additional testing should be done prior to final design. Based on preliminary test results, footing and/or grade beams founded on the undisturbed soil should be designed for a maximum allowable bearing capacity of between 2,000 to 4,500 pounds per square foot (dead load plus 1 /2 live load). To counteract swelling pressures which will develop if the subsoils be wetted, all footings should be designed for a minimum dead load pressure of 500 to 1,500 per square foot. Where drilled pier foundation systems are used, the piers would have minimum 12 to 15 foot lengths and extend a minimum of 5 feet into the bedrock stratum. Based on preliminary test results, the piers should be designed for a maximum end bearing pressure of between 15,000 to 30,000 psf and skin friction of 1,500 to 3,000 psf. For preliminary design purposes, the uplift force on each pier can be determined on the basis of the following equation. 7 Preliminary Geotechnical Engineering Exploration Terracon Merrick & Company TCW Project No. 20955191 • Site Clearing: 1. Strip and remove existing vegetation, debris, 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 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. All exposed areas which will receive fill, once properly cleared and benched where necessary, should be scarified to a minimum depth of 6 inches, conditioned to near optimum moisture content, and compacted. e Utility and Site Grading: 1. It is anticipated that excavations for the proposed construction can be accomplished with conventional earthmoving equipment. 2. Excavations penetrating the well -cemented sandstone bedrock may require the use of specialized heavy-duty equipment, together with drilling and blasting, ripping or jack -hammering to facilitate rock break-up and removal. 3. Depending upon depth of excavation and seasonal conditions, groundwater may be encountered in excavations on the site. Groundwater seepage should be anticipated for excavations approaching the level of the bedrock. 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. 11 Preliminary Geotechnical Engineering Exploration Merrick & Company TCW Project No. 20955191 Terracon Field and Laboratory Test Results: Field and laboratory test results indicate the clay soils are medium to very stiff in consistency and exhibit moderate to high bearing characteristics and moderate to high swell potential. The bedrock is moderately hard to hard and cemented to well cemented and exhibits very high bearing characteristics and low swell potential. Groundwater Conditions: Groundwater was encountered in Boring 2 at the time of drilling and when checked 1 to 10 days after drilling, groundwater was encountered in Borings 2 through 6 at approximate depths of 6 to 14 feet. Boring 1 remained dry. These observations represent groundwater conditions at the time of the readings, 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. Zones of perched and/or trapped groundwater may also occur at times in the subsurface soils overlying bedrock, on top of the bedrock surface or within permeable fractures in the bedrock materials. The location and amount of perched water is dependent upon several factors, including hydrologic conditions, type of site development, irrigation demands on or adjacent to the site, fluctuations in water features, seasonal and weather conditions. Fluctuations in groundwater levels can best be determined by implementation of a groundwater monitoring plan. Such a plan would include installation of groundwater monitoring wells, and periodic measurement of groundwater levels over a sufficient period of time. The possibility of groundwater fluctuations should be considered when developing design and construction plans for the project. PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS Site Development Considerations: The site appears suitable for the proposed construction. Although fill or underground facilities, such as septic tanks, cesspools, basements and utilities, were not observed during site reconnaissance, such features might be encountered during construction. 5 a Preliminary Geotechnical Engineering Exploration Merrick & Company TCW Project No. 20955191 Terracon The regional dip of the Pierre shale in this area is slight and in an easterly direction. Seismic activity in the area is anticipated to be low; therefore, from a structural standpoint, the property should be relatively stable. It is anticipated that the weathered bedrock and the majority of the firm bedrock may be excavated by conventional heavy-duty construction equipment equivalent to a D-8 tractor and ripper or a large track -mounted backhoe. However, the sandstone becomes dense at lower depths. This dense sandstone at depth may require the use of special heavy-duty excavation equipment or possibly blasting for excavation. Due to the relatively flat to gently -rolling nature of the site, geologic hazards due to mass movement caused by gravity, such as landslides, mudflows, rockfalls, etc., are not anticipated. With proper site grading around structures and proper drainage for streets and drive areas, erosional problems at the site should be minimal. It is recommended that construction not be placed within the wet areas in the central portion of the site without proper draining and filling. The site is underlain by the Cretaceous Pierre Formation. The Pierre shale is not known to contain economic deposits of coal, limestone, or quarry rock. Sand and gravel was not encountered at the site, and economic deposits of these materials are not anticipated. Background levels of radioactivity are anticipated to be low in this area. However, the possibility does exist that abnormally high radiation rates may exist on the property. A detailed study of radon gas or radiation hazards at the site is beyond the scope of this report. It is suggested that a more detailed study be made prior to construction to more accurately determine if radiation hazards exist at the site. Soil and Bedrock Conditions: As presented on the Logs of Boring, the subsurface soils were encountered in order of increasing depths. • Silty Topsoil: The area tested is overlain by a 6-inch layer of silty topsoil. The topsoil has been penetrated by root growth and organic matter. • Sandy Lean Clay: This stratum underlies the topsoil and extends to the bedrock below and/or the depths explored. The sandy lean clay is plastic, dry to wet and medium to very hard. • Sandstone-Siltstone Bedrock: The bedrock was encountered in Borings 2, 5 and 6 at depths of Yz to 1'3 feet and extends to greater depths. The upper 1 to 1'/2 feet of the bedrock is highly weathered; however, the underlying sandstone interbedded with claystone is well -cemented and hard. fv Preliminary Geotechnical Engineering Exploration Terracon Merrick & Company TCW Project No. 20955191 o Water content 0 Expansion e Dry density i Atterberg limits 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 tests were performed in general accordance with the applicable ASTM, local or other accepted standards. SITE CONDITIONS The site surrounds an existing lake and wetlands areas. The area is vegetated with native grass and Russian olive and cottonwood trees and brush. Cattails were noted growing in the wetlands area. Fences are located throughout the property along with several oil wells. The site is bordered on all sides by fenced pasture land. Drainage, in general, is from the north, south, east and west toward the lake and wetlands in the center of the project. The property is bordered on the west by Larimer County Road 13, on the southwest by Richards Lake, and on the north and east by open pasture. 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 Piedmont in this region. The site is underlain by the Cretaceous Pierre Formation. The Pierre shale at the site consists of sandstone and claystone. Bedrock was encountered in Borings 2, 5, and 6 at depths of '/z to 13 feet, and it is anticipated it underlies the remainder of the site at depths of 20 to 25 feet. The bedrock is overlain by residual and alluvial clays of Pleistocene and/or Recent Age. A Geologic Map, Soil Map and legend are included in Appendix A. 3 b 10 Preliminary Geotechnical Engineering Exploration Terracon Merrick & Company TCW Project No. 20955191 SITE EXPLORATION The scope of the services performed for this project included site reconnaissance by a geotechnical engineer and an engineering geologist, a subsurface exploration program, laboratory testing and engineering analysis. Field Exploration: A total of 6 test borings were drilled on July 6, 1987 and October 31, 1995 to depths of 15 feet at the locations shown on the Site Plan, Figure 1. The borings were drilled within the area of proposed buildings. 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 property lines and/or existing site features. Elevations were taken at each boring location from a topographic map prepared by Merrick & Company. 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 geotechnical engineer during the drilling operations. At selected intervals, samples of the subsurface materials were taken by means of pushing thin -walled Shelby tubes, or 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 site exploration, and 1 to 10 days after drilling. Laboratory Testing: All samples retrieved during the field exploration were returned to the laboratory for observation by the project geotechnical engineer, and were classified in accordance with the Unified Soil Classification System described in Appendix C. Samples of bedrock were classified in accordance with the general notes for Bedrock Classification. At that time, the field descriptions were confirmed or modified as necessary, 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: 2 PRELIMINARY GEOTECHNICAL ENGINEERING REPORT Terracon THE POND AT HEARTHFIRE DOUGLAS ROAD AND COUNTY ROAD 13 FORT COLLINS, COLORADO TCW Project No. 20955191 April 22, 1996 INTRODUCTION This report contains the results of our preliminary geotechnical engineering exploration for the proposed first filing of The Pond at Hearthfire located at the southeast corner of Larimer County Road 13 and Douglas Road, northeast of Fort Collins, Colorado. The site is located in the West 1 /2 of Section 30, Township 8 North, Range 68 West of the 6th Principal Meridian. The purpose of these services is to provide preliminary geotechnical engineering information relative to: • subsurface soil and bedrock conditions • groundwater conditions • earthwork • preliminary foundation systems • basement construction • preliminary floor slab design and construction • utilities The conclusions and recommendations contained in this report are based upon the results of limited field and laboratory testing, engineering analyses, and experience with similar soil conditions and structures and our understanding of the proposed project. Prior to final design, additional studies will be required. PROPOSED CONSTRUCTION The site will be developed as a residential subdivision with single-family and multifamily housing. Residential streets will be constructed throughout the project area. Grading plans were not available at the time of preparation of this report, and it is anticipated that some cut and fill will be required. 4 [7 Preliminary Geotechnical Engineering Exploration Merrick & Company TCW Project No. 20955191 TABLE OF CONTENTS (Cont'd) Terracon APPENDIX A Figure Nos SitePlan ................................................. 1 GeologicMap ............................................. 1 SoilsMap ................................................ 1 Logs of Borings ..................................... Al thru A6 Legend.................................................. 7 APPENDIX B Summary of Test Results .................................... B1 APPENDIX C: GENERAL NOTES Drilling & Exploration ....................................... �.' i Unified Soil Classification .................................... C2 Bedrock Classification, Sedimentary Bedrock ....................... C3 Laboratory Testing, Significance and Purpose ...................... C4 Report Terminology .................................. C5 Preliminary Geotechnical Engineering Exploration Terracon Merrick & Company TCW Project No. 20955191 TABLE OF CONTENTS Page No. Letter of Transmittal ............................................... ii INTRODUCTION................................................ 1 PROPOSED CONSTRUCTION ....................................... 1 2 SITE EXPLORATION ............................................. 2 Field Exploration .......................................... 2 Laboratory Testing ......................................... SITE CONDITIONS .............................................. 3 SUBSURFACE CONDITIONS ....................................... 3 Geology................................................ 3 Soil and Bedrock Conditions .................................. 4 Field and Laboratory Test Results ............................... 5 Groundwater Conditions ..................................... 5 PRELIMINARY CONCLUSIONS AND RECOMMENDATIONS .................. 5 Site Development Considerations ............................... 5 Site Clearing ........................................ 6 Utility and Site Grading .................................. 6 Fill Materials ........................................ 7 Foundation Systems ........................................ 7 Basement Construction ...................................... 8 Floor Slab Design and Construction ............................. 8 Compliance ......................................... 8 PRELIMINARY GENERAL COMMENTS ................................ 8 L r Preliminary Geotechnical Engineering Exploration Terracon Merrick & Company TCW Project No. 20955191 Preliminary earthwork considerations are presented in the report. We appreciated being of service during the preliminary geotechnical engineering phase of this project, and are prepared to assist during the final geotechnical phase as well. If you have any questions concerning this report or any of our testing, inspection, design and consulting services, please do not hesitate to contact us. Sincerely, TERRACON CONSULTANTS WESTERN, Empire Division SJ: S.•1�F\CAic ,\. Prepared by: / a37' 4 A.IPG Neil R. Sherr Senior Engineering Geologist Reviewed by: ^ William J. Attwooll, P.E. Assistant Office�Managd1-(, Sr NRS/WJA/cic Copies to: Addressee (2) Jim Sell Design (1) I 51 lrerrac®n CONSULTANTS WESTERN, INC. EMPIRE DIVISION P.O. Box 503 • 301 N. Howes Fort Collins, Colorado 80522 (970)484-0359 Fax (970) 484-0454 Larry G. O'Dell, P.E. Neil R, Sherrod, C.P.G. April 22, 1996 Merrick & Company 2450 South Peoria Street Aurora, Colorado 80014 Attn: Mr. Glen Tulk Re: Preliminary Geotechnical Engineering Report, The Pond at Hearthfire Douglas Road and County Road 13, Fort Collins, Colorado TCW Project No. 20955191 Terracon Consultants Western, Inc:, Empire Division, has completed a preliminary geotechnical engineering exploration for the proposed Filing 1 of The Pond at Hearthfire to be located on Larimer County Road 13 south of Douglas Road, northeast of Richards Lake and northeast of Fort Collins, Colorado. The results of our engineering study, including the boring location diagram, laboratory test results, test boring records, and the preliminary geotechnical recommendations needed to aid in the preliminary design and construction of foundations and other earth connected phases of this project are attached. The subsurface soils at the site consist of sandy lean clays underlain by sandstone- claystone bedrock. The information obtained by the results of field exploration and laboratory testing completed for this study indicate the soils at the site exhibit moderate to high swell potential and moderate to high bearing characteristics. The bedrock at the site exhibits high bearing characteristics and low swell potential. The soils at anticipated foundation bearing depths exhibit medium to stiff consistency, and the bedrock varies from medium hard to very hard to cemented and well cemented. Based on the preliminary geotechnical engineering analyses, subsurface exploration and laboratory test results, we recommend the proposed residences be supported on a conventional -type spread footing and grade beam and/or straight shaft pier foundation systems. 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. If no movement can be tolerated, a structural floor system should be specified. Offices of The Terracon Companies, Inc. Geotechnical, Environmental and Materials Engineers Arizona ■ Arkansas ■ Colorado ■ Idaho ■ Illinois ■ Iowa ■ Kansas III Minnesota Missouri ■ Montana ■ Nebraska u Nevada ■ Oklahoma ■ Texas ■ Utah ■ Wyoming QUALITY ENGINEERING SINCE 1965 PRELIMINARY GEOTECHNICAL ENGINEERING REPORT THE POND AT HEARTHFIRE DOUGLAS ROAD AND COUNTY ROAD 13 FORT COLLINS, COLORADO TCW PROJECT NO. 20955191 April 22, 1996 Prepared for. MERRICK & COMPANY 2450 SOUTH PEORIA STREET AURORA, COLORADO 80014 ATTN: MR. GLEN TULK Prepared by. Terracon Consultants Western, Inc. Empire Division . 301 North Howes Street Fort Collins, Colorado 80521 Empire Laboratories, Inc. A Division of The Terracon Companies, Inc.