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Home My WebLink AboutHARMONY NEIGHBORHOOD CENTRE P.U.D. - PRELIMINARY - 33-94 - SUBMITTAL DOCUMENTS - ROUND 1 - GEOTECHNICAL (SOILS) REPORT.A'y"x* pneumatic -tired rollers, three -wheel power rollers, vibratory compactors, or other approved equipment well -suited to the soil being compacted. If a sheepfoot roller is used, it shall be provided with cleaner bars attached in a manner which will prevent the accumulation of material between the tamper feet. The rollers should be designed so that effective weight can be increased. MOISTURE -DENSITY DETERMINATION Samples of representative fill materials to be placed shall be furnished .by the contractor to the soils engineer for determination of maximum density and optimum moisture or percent of Relative Density for.these materials. Tests for this determination will be made using methods conforming to requirements of ASTM D 698, ASTM D 1557, or ASTM D 2049. Copies of the results of these tests will be furnished to the owner, the project engineer, and the contractor. These test results shall be the basis of control for all compaction effort. DENSITY TESTS The density and moisture content of each layer of compacted fill will be determined by the soils engineer in accordance with ASTM D 1556, ASTM D 2167, or ASTM D 2922. Any material found not to comply with the minimum specified density shall be recompacted until the required density is obtained. Sufficient density tests shall be made and submitted to support the soils engineer's recommendations. The results of density i tests will also be furnished to the owner, the project engineer, and the contractor by the soils engineer. i r n A -N • PLACING FILL No sod, brush, frozen or thawing material, or other unsuitable material shall be placed in the fill, and -no fill shall be placed during unfavorable weather conditions. All clods shall be broken into small pieces, and distribution of material in the fill shall be such as to preclude the formation of lenses of.material differing from the surrounding material. The materials shall be delivered to and spread on the fill surface in a manner which will result in a uniformly compacted fill. Each layer shall be thoroughly blade mixed during spreading to insure uniformity of material and moisture in each layer. Prior to compacting, each layer shall have a maximum thickness of eight inches, and its upper surface shall be approximately horizontal. Each successive 6" to 8" lift of fill being placed on slopes or hillsides should be benched into the existing slopes, providing good bond between the fill and existing ground. MOISTURE CONTROL While being compacted, the fill material in each layer shall as nearly as practical contain the amount of moisture required for optimum compaction or as specified, and the moisture shall be uniform throughout the fill. The contractor may be required to add necessary moisture to the fill material and to uniformly mix the water with the fill material if, in the opinion of the soils engineer, it is not possible to obtain uniform moisture content by adding water on the fill surface. If, in the opinion of the soils engineer, the material proposed for use in the compacted fill is too wet to permit adequate compaction, it shall be dried in an acceptable manner prior to placement and compaction. COMPACTION When an acceptable, uniform moisture content is obtained, each layer shall be compacted by a method acceptable to the soils engineer and as specified in the foregoing report as determined by applicable standards. Compaction shall be performed by rolling with approved tamping rollers, C-3 • . ) • APPENDIX C. Suggested Specifications for Placement of Compacted Earth Fill and/or Backfills. GENERAL A soils engineer shall be on -site to provide continuous observation during filling and grading operations and shall be the owner's repre- sentative.to inspect placement of all compacted -fill and/or backfill on the project. The soils engineer shall approve all earth materials prior to their use, the methods of placing, and the degree of compaction obtained. MATERIALS Soils used for all compacted fill and backfill shall be approved by the soils engineer prior to their use. The upper two (2) feet of compacted earth backfill placed adjacent to exterior foundation walls shall be an impervious, nonexpansive material. No material, including rock, having a maximum dimension greater than six inches shall be placed in any fill. Any fill containing rock should be carefully mixed to avoid nesting and creation of voids. In no case shall frozen material be used as a fill and/or backfill material. J PREPARATION OF SUBGRADE All topsoil, vegetation (including trees and brush), timber, debris, rubbish, and other unsuitable material shall be removed to a depth satisfactory to the soils engineer and disposed of by suitable means before beginning preparation of the subgrade. The subgrade surface of the area to be filled shall be scarified a minimum depth of six inches, moistened as necessary, and compacted in a manner specified below for the subsequent layers of fill. Fill shall not be placed on frozen or muddy ground. APPENDIX C. Boring No. Depth (Ft.) Liquid Limit Plastic Limit Plasticity Index % Passing 200 Group Index Unified AASHTO SUMMARY OF TEST RESULTS Atterberg Summary 11 12 .24 25 30 31 32 33 34 1.0-2.0 1.0-2.0 1.0-2.0 1.0-2.0 1.0-2.0 1.0-2.0 1.0-2.0 1.0-2.0 1.0-2.0 35.8 28.7 28.9 31.7 37.2 35.5 37.2 35.9 38.3 19.6 15.1 17.5 16..7 18.0 19.0 19.5 20.9 19.5 16.2 13.5 11.4 15.0 19.2 16.5 17.7 14.9 18.8 .76.9 63.9 42.8 69.8 78.6 58.9 56.5 41.1 75.4 11.3 5.9 1.5 8.3 14.0 7.1 7.2 2..4 13.1 Classification CL CL Sc CL CL CL CL Sc CL A-6(11) A-6(6) A-6(2) A-6(8) A-6(14) A-6(7) A-6(7) A-6(2) A-6(13) a. SUMMARY OF TEST RESULTS Swelling Pressures Boring Depth % Moisture Dry Density Swelling No. (Ft.) Before Test P.C.F. Pressure PSF 3 3.0-4.0 14.5 104.5 620 4 3.0-4.0 11.8 95.0 240 8 3.0-4.0 13.3 91.5 20 21 3.0-4.0 12.7 115.7 1345 22 3.0-4.0 11.2 89.9 115 25 1.0-2.0 11.2 105.4 550 26 3.0-4.0 12.7 108.6 515 28 3.0-4.0 11.0 107.4 760 0 10 SUMMARY OF TEST RESULTS BORING NO. DEPTH FT. % MOISTURE DRY DENSITY P.C.F. UNCONFINED COMPRESSIVE STRENGTH-P.S.F. WATER SOLUBLE SULFATES-% PENETRATION BLOWS/INCHES 32 1.0-2.0 10.5 107.8 132530 2.0-3.0 14/12 6.0-7.0 6.5 15/12 33 1.0-2.0 9.6 2.0-3.0 11/12 6.0-7.0 14.0 9/12 34 1.0-2.0 12.2 103.6 10,060 2.0-3.0 I 12/12 6.0-7.0 15.4 8/12 EMPIRE LABORATORIES, INC. SUMMARY OF TEST RESULTS BORING DEPTH % DRY DENSITY P.C.F. UNCONFINED COMPRESSIVE STRENGTH-P.S.F. WATER SOLUBLE SULFATES-% PENETRATION BLOWSPNCHES NO. FT. MOISTURE 28 0.5-1.5 11.6 14/12 3.0-4.0 11.0 109.7 132460 4.0-5.0 19/12 7.0-8.0 12.5 .109.6 55410 8.0-9.0 6/12 13.5-14.5 17.2 9/12 18.5-19.0 12.5 50/6 29 1.0-2.0 18.3 2.0-3.0 5/12 6.0-7.0 12.0 8/12 30 1.0-2.0 12.8 112.1 12,250 2.0-3.0 15.6 14/12 6.0-7.0 16.2 5/12 31 1.0-2.0 11.1 110.3 13,810 2.0-3.0 13/12 6.0-7.0 13.6 3/12 I I I i EMPIRE LABORATORIES, INC. SUMMARY OF TEST RESULTS BORING NO. DEPTH FT. % MOISTURE DRY DENSITY P.C.F. UNCONFINED COMPRESSIVE STRENGTH-P.S.F. WATER SOLUBLE SULFATES-% PENETRATION BLOWS/INCHES 24 1.0-2.0 9.0 107.5 42450 2.0-3.0 11/12 6.0-7.0 18.8 7.0-8.0 11 /12 13.5-14.5 4.3 9/12 25 1.0-2.0 11.2 109.0 119930 2.0-3.0 12/12 6.0- 7.0 8.9 21/12 26 0.5-1.5 10.6 10/12 3.0-4.0 12.7 100.8 4.0- 5.0 6/ 12 7.0-8.0 21.5 89.9 19670 8.0-9.0 2/12 13.5-14.5 22.8 4/12 27 0.5-1.5 11.4 9/12 3.0-4.0 10.8 98.4 52610 .0150 4.0-5.0 9/12 7.0-8.0 15.2 106.6 39330 8.0-9.0 4/12 - 13.5-14.5 21.9 22/12 I I ____I I - EMPIRE LABORATORIES, INC. I I SUMMARY OF TEST RESULTS BORING DEPTH % DRY DENSITY UNCONFINED COMPRESSIVE STRENGTH-P.S.F. WATER SOLUBLE SULFATES-% PENETRATION BLOWS/INCHES NO. FT. MOISTURE P.C.F. 21 0.5-1.5 10.9 20/12 3.0-4.0 12.7 115.8 203800 4.0-5.0 19/12 7.0-8.0 21.9 98.7 2,880 8.0-9.0 8/12 13.5-14.5 23.8 7/12 22 0.5-1.5 14.6 .13/12 3.0-4.0 11.2 105.2 7,870 4.0-5.0 .15/12 7.0-8.0 19.1 8.0-9.0 17.1 31/12 13.5-13.9 13.4 50/5 , 23 0.5-1.5 10.3 13/12 3.0-4.0 14.9 4.0- 5.0 20/ 12 7.0-8.0 7.0 117.0 8.0-9.0 14/12 13.5-13.9 12.5 50/5 EMPIRE- LABORATORILS, INC. SUMMARY OF TEST RESULTS BORING NO. DEPTH FT. % MOISTURE DRY DENSITY P.C.F. UNCONFINED COMPRESSIVE STRENGTH-P.S.F. WATER SOLUBLE SULFATES-% PENETRATION BLOWS/INCHES 18 0.5-1.5 11.1 9/12 3.0-4.0 12.4 100.5 69310 4.0- 5.0 8/12 7.0-8.0 11.5 113.4 3,370 8.0-9.0 8/12 13.5-14.5 24.2 4/12 19 0.5-1.5 13.3 12/12 3.0-4.0 12.4 101.4 32090 4.0-5.0 4/12 7.0-8.0 19.7 104.7 2,910 8.0-9.0 6/12 13.5-14.5 20.6 12/12 20 0.5-1.5 11.7 14/12 3.0-4.0 13.9 107.8 152370 0.0075 4.0-5.0 11/12 7.0-8.0 26.0 98.0 930 8.0-9.0 4/12 13.5-14.5 26.2 12/12 18.5-19.5 14.4 13/12 23.5-24.4 19.5 50/11 I I I I EMPIRE LABORATORIES, INC. BORING' NO. DEPTH FT. % MOISTURE 15 0.5-1.5 13.0 3.0-4.0 9.8 4.0-5.0 7.0-8.0 16.7 8.0-9.0 13.5-14.5 22.1 16 0.5-1.5 10.2 3.0-4.0 9.8 4.0-5.0 7.0-8.0 11.9 8.0-9.0 13.5-14.5 23.7 17 0.5-1.5 10.0 3.0-4.0 4.0-5.0 12.3 7.0-8.0 13.8 8.0-9.0 13.5-14.5 20.5 SUMMARY OF TEST RESULTS DRY DENSITY UNCONFINED COMPRESSIVE P.C.F. STRENGTH-P.S.F. 92.6 105.6 2, 390 86.8 3,660 97.8 110.6 1 32230 WATER SOLUBLE SULFATES-% RATION /INCHES 17/12 7/ 12 5/12 5/12 13/12 11/12 10/12 10/12 11/12 11/12 5/12 7/12 lo EMPIRE LABORATORIES, INC. SUMMARY OF TEST RESULTS BORING DEPTH % DRY DENSITY UNCONFINED COMPRESSIVE STRENGTH-P.S.F. WATER SOLUBLE SULFATES-% PENETRATION BLOWS/INCHES NO. FT. MOISTURE P.C.F. 13 0.5-1.5 16.3 15/12 3.0-4.0 16.6 4.0-5.0 5/12 7.0-8.0 14.5 112.3 3,970 8.0-9.0 4/12 13.5-14.5 18.4 8/12 14 0.5-1.5 10.7 15/12 3.0-4.0 10.3 86.7 2,600 4.0-5.0 6/12 7.0-8.0 7.3 102.2 23310 8.0-9.0 7/12 13.5-14.5 21.0 4/12 18.5-19.5 19.8 11/12 23.5-24.5 10.5 23/12 28.5-29.5 23.2 10/12 33.5-33.9 15.1 50/5 EMPIRE LABORATORIES, INC. SUMMARY OF TEST RESULTS BORING NO. DEPTH FT. % MOISTURE DRY DENSITY P.C.F. UNCONFINED COMPRESSIVE STRENGTH-P.S.F. WATER SOLUBLE SULFATES-% PENETRATION BLOWS/INCHES 10 0.5-1.5 14.6 12/12 3.0-4.0 9.8 4.0-5.0 10/12 7.0-8.0 14.7 96.7 21410 8.0-9.0 9/12 13.5-14.5 22.2 4/12 11 1.0-2.0 13.6 97.8 3,850 2.0-3.0 8/12 6.0-7.0 14.8 110.7 10,470 7.0-8.0 26/12. 13.5-14.5 19.3 11/12 12 1.0-2.0 13.5 105.7 11,240 2.0-3.0 9/12 6.0-7.0 18.9 103.8 4,230 7.0- 8.0 8/ 12 13.5-14.5 24.3 5/12 EMPIRE LABORATORIES, INC. I. d SUMMARY OF TEST RESULTS BORING DEPTH % DRY DENSITY P.C.F. UNCONFINED COMPRESSIVE STRENGTH-P.S.F. WATER SOLUBLE SULFATES-% PENETRATION BLOWS/INCHES NO. FT. MOISTURE 7 0.5-1.5 9.6 19/12 3.0-4.0 7.0 4.0-5.0 17/12 7.0-8.0 6.7 8.0-9.0 16/12 13.5-14.5 18.4 7/12 8. 0.5-1.5 12.6 15/12 3.0-4.0 13.3 91.8 29520 4.0-5.0 19/12 7.0-8.0 12.3 111.0 13,000 8.0-9.0 14/12 13.5-14.5 22.6 7/12 18.5-19.5 20.3 10/12 23.5-24.5 23.2 19/12 28.5-29.2 17.5 .0200 50/8 9 0.5-1.5 10.7 10/12 3.0-4.0 10.9 86.1 19030 4.0-5.0 6/12 7.0-8.0 8.2 8.0-9.0 8/12 13.5-14.5 17.1 10/12 I I I I EMPIRE LABORATORIES, INC. IF SUMMARY OF TEST RESULTS BORING NO. DEPTH FT. % MOISTURE DRY DENSITY P.C.F. UNCONFINED COMPRESSIVE STRENGTH-P.S.F. WATER SOLUBLE SULFATES-% PENETRATION BLOWS/INCHES 4 0.5-1.5 11.7 11/12 3.0-4.0 11.8 103.0 13,200 4.0-5.0 13/12 7.0-8.0 10.5 111.0 14,550 8.0-9.0 20/12 13.5-14.5 21.5 12/12 5 0.5-1.5 10.4 16/12 3.0-4.0 9.1 107.6 12,980 4.0-5.0 13/12 7.0-8.0 8.5 11/12 13.5-14.5 23.6 8/12 6 0.5-1.5 13.8 12/12 3.0-4.0 8.5 90.8 11190 4.0-5.0 12/12 7.0-3.0 6.5 112.9 6,320 8.0-9.0 4/12 13.5-14.5 20.4 6/12 EMPIRE LABORATORIES, INC. SUMMARY OF TEST RESULTS BORING NO. DEPTH FT. % MOISTURE DRY DENSITY P.C.F. UNCONFINED COMPRESSIVE STRENGTH-P.S.F. WATER SOLUBLE SULFATES-% PENETRATION BLOWS/INCHES 1 0.5-1.5 14.0 10/12 3.0-4.0 7.9 107.7 3,830 4.0-5.0 12/12 7.0-8.0 13.2 .0200 8.0-9.0 2/12 13.5-14.5 24.6 6/12 18.5-19.5 16.8 10/12 23.5-24.5 19.3 .28/12 28.5- 29.0 17.4 50/ 6 2 0.5-1.5 11/12 3.0-4.0 16.8 88.0 22070 4.0- 5.0 6/12 7.0-8.0 18.1 104.7 22930 8.0-9.0 3/12 13.5-14.5 14.0 22/12 3 0.5-1.5 16.0 10/12 3.0-4.0 14.5 111.3 18,740 4.0-5.0 15/12 7.0-8.0 15.3 108.0 3,280 8.0-9.0 4/12 13.5-14.5 10.9 1.9/12 EMPIRE LABORATORIES, INC. I .75 o .70 0 0 .65 .60 v 10 CONSOLIDATION --SWELL TEST BORING NO. 26 DEPTH-.!- _0 DRY DENSITY 94•8#/Ft3 % MOISTURE 2. 7 G U.T 0.5 1.0 5 10 APPLIED PRESSURE-TONS/SQ. FT. H,.O 0.1 0.5 1.0 APPLIED PRESSURE-TONS/SQ. FT. B-6 •ru nnr wn�nwti.n.�.. ...� 5 10 r .. 70 .65 .55 CONSOLIDATION --SWELL TEST BORING NO. 15 DEF DRY DENSITY 2-- -ALF $4- �, j I % MOISTURE 9 _ 83 0.1 0.5 1.0 5 10 ` APPLIED PRESSURE-TONS/SQ. FT. 0.1 0.5 1.0 APPLIED PRESSURE-TONS/SQ. FT. 5 10 O CONSOLIDATION --SWELL TEST .85 BORING NO. 13 DEPTH 3. 0 DRY DENSITY 87.6>/Ft3 % MOISTURE 1 6.6% .80 o .75 o o .. 70 .65 0 U.1 u.s i.0 s 10 APPLIED PRESSURE—TONS/SQ. FT. 0.1 0.5 1.0 APPLIED PRESSURE—TONS/S?. FT. R_4 s 10 J J 0` r 0 H Q J Z 0 u 0.1 CONSOLIDATION --SWELL TEST 0.5 1.0 APPLIED PRESSURE—TONS/SQ. FT. BORING NO 1 DEPTH 7.0 DRY DENSITY 119.4#/Ft3 MOISTURE_ 13.2% 5 10 0.1 0.5 1.0 5 10 APPLIED PRESSURE—TONS/SQ. FT. B-3 .75 .70 0 a 0 o .65 . 60 .55 0 15 L 0.1 CONSOLIDATION --SWELL TEST APPLIED PRESSURE-TONS/SQ. FT. 0.5 1.0 APPLIED PRESSURE-TONS/SQ. FT. B- 2 5 10 APPENDIX B. 4975 LOG OF BORINGS No. 3.2 IJo. 33 90911 Will ►� I: IS ivy FAM A-12 EMPIRE LABORATORIES, INC. 4975 4970 4965 LOG OF BORINGS �.r vctn V • A-11 EMPIRE LABORATORIES, INC. 4980 4975 4970 4965 4960 4955 LOG OF BORINGS rvo.z6 vra ' PAM M- WV �E A AM WE 'COMM m mrs. w�- r m� A-10 EMPIRE LABORATORIES, INC. 4975 4970 4965 4960 LOG OF BORINGS `l &lo.21 No.27 ►ao.23 - -_ hla-2� i�—: KFA -1 ' WIN wor A-9 EMPIRE LABORATORIES, INC. LOG OF BORINGS v/MON 4980 4975 4970 4965 4960 4955 4950 w -W-AW -=-wll��= W-I�_ =-ffft rr.im � -NA s� A- 8 EMPIRE LABORATORIES, INC. 4980 4975 4970 4965 4960 4955 4950 LOG OF BORINGS FAA Will A �- �) -W -WA EWA -WN --WA W -WANNINErm -M23/12 �� - IFA v� m MINE o 50 =sao A-7 EMPIRE LABORATORIES, INC. m 4975 4970 4965 4960 LOG OF BORINGS EVA :OaEM ��r��-� � Sm -��-�� • :M®:WA'-�m ' .ro =im A- 6 EMPIRE LABORATORIES, INC. LOG OF BORINGS ME 4975 4970 4965 4960 4955 4950 L7QI era --� I. W ©E WA WA' INA MIN FAFA !vA WAR m� m� 5 is A— 5 EMPIRE LABORATORIES, INC. ,m 4975 4970 4965 4960 4955 4950 LOG OF BORINGS WA 101MA NVA plrm�� MW Wr ®.M WAA Qo. e� m m rs� m NOTE: Elevations interpolated from a topographic plan renarpd by ZVFK. A- 4 EMPIRE LABORATORIES, INC. KEY TO BORING LOGS q TOPSOIL •--• •;, GRAVEL FILL •�`�: SAND & GRAVEL .1e /10 SILT /. . -SILTY SAND & GRAVEL CLAYEY SILT o p 0 COBBLES SANDY SILT ' v� SAND, GRAVEL & COBBLES ® CLAY ® WEATHERED BEDROCK SILTY CLAY SILTSTONE BEDROCK SANDY CLAY ®ZA CLAYSTONE BEDROCK aSAND SANDSTONE BEDROCK �• SILTY SAND LIMESTONE CLAYEY SAND " ` ■ x GRANITE ® SANDY SILTY CLAY ❑ ' SHELBY TUBE SAMPLE STANDARD PENETRATION DRIVE SAMPLER WATER TABLE 24 HOURS AFTER DRILLING C HOLE CAVED T 5/12 Indicates that 5 blows of a 140 pound hammer falling 30 inches was requires A- 3 EMPIRE LABORATORIES, INC. TEST BORING LOCATION PLAN 1 -ZOO ® No. 34 tio.32 ® c1I LV. :ice � � • �_ AIo.22 z� ® No.26 _ No• 3Q Ne.29 "IMURR46Y AVE, -- -A-2 APPENDIX A. (6) It is recommended that all compaction requirements specified herein be verified in the field with density tests performed under the direction of the geotechnical engineer. (7) It is recopnnended that a registered professional engineer design the foundations using the recommendations presented in this report. GENERAL CCAMENTS This report has been prepared to aid in the evaluation of the property and to assist the architect and/or engineer in the design of this project. In the event that any changes in the design of the structures or their locations are planned, the conclusions and recommen- dations contained in this report will not be considered valid unless said changes are reviewed and conclusions of this report modified or approved in writing by Empire Laboratories, Inc., the soils engineer of record. Every effort was made to provide comprehensive site coverage through careful locations of the test borings, while keeping the site 3 investigation economically feasible. Variations in soil and groundwater conditions between test borings may be encountered during construction. In order to permit correlation between the reported subsurface conditions and the actual conditions encountered during construction and .to aid in carrying out the plans and specifications as originally contemplated, it is recommended that Empire Laboratories, Inc. be retained to perform continuous construction review during the excavation and foundation phases of the work. Empire Laboratories, Inc. assumes no responsibility for compliance with the recommendations included in this report unless they have been retained to perform adequate on -site construction review s during the course of construction. j -11- The base course should be placed on the subgrade at or near optimum moisture and compacted to at least ninety-five percent (95%) of Standard Proctor Density ASTM D 698-78. (See Appendix C.) It is important that the base course be shaped to grade so that proper drainage of the pavement area is obtained. The asphaltic concrete should meet City of Fort Collins specifi- cations or equivalent and be placed in accordance with those speci- fications. GENERAL RECOMMENDATIONS (1) Laboratory tests indicate that water soluble sulfates in the soil are negligible, and a Type I cement may be used in all_ concrete exposed to subsoils. All slabs on grade subjected to de-icing chemicals should be composed of a more durable Cori= Crete using a Type II cement with low water -cement ratios and higher air contents. (2) Finished grade should be sloped away from the structures on all sides to give positive drainage. Five percent (5%) for the first five (5) feet away from the structures is the sug- gested slope. (3) 3ackfill around the outside perimeter of the structures should be mechanically compacted at optimum moisture to at least ninety-five percent (95%) of Standard Proctor Density ASTM D 698-78. (See Appendix C.) Puddling should not be permitted as a method of compaction. (4) Gutters and downspouts should be designed to carry roof runoff water well beyond the backfill area. (5) Underground sprinkling systems should not be installed within ten (10) feet of the structures, and this recommendation should be taken into account in the landscape planning. -10- Select Subbase Select Base Course Asphaltic Concrete Total Pavement Thickness Collector Arterial 4" 7" 6" 6" 2" 2" 12" 15" We understand that Monte Carlo and Wheaton Drives are both collector streets. Harmony Road to the south of the property is an arterial street. Within the proposed Neighborhood Center, the following pavement thicknesses are recommended using the group index design procedure: Automobile Parking Service Drives Select Subbase --- 4" Select 5ase Course 7" Asphaltic Concrete 2" 2" Total Pavement Thickness y" 12" ilveem stabilometer tests are presently being performed on representative samples or the subgrade materials. When these tests are completed, pavement thicknesses using the new City of Fort Collins design procedure will be submitted. At that time, we will also include concrete pavement alternatives. The base course overlying the subgrade should consist of a hard, durable, crushed rock or stone and filler and should have a minimum "R" value of 80. The composite base course material should be free from vegetable matter and lumps or balls of clay and should meet the Colorado Department of Highways Specification Class 6 Aggregate Base Course which follows: Sieve Size % Passing 3/4" 100 #4 30-65 #8 25-55 #200 3-12 Liquid Limit - 30 Maximum Plasticity Index - 6 Maximum I vation should be accomplished as discussed in the "Site of this report. As previously discussed, the near-sur tered at the site are plastic and may be susceptible t, are allowed to dry below their in situ moisture content rewetted. To prevent drying of the clay soils, foundal excavations should not be allowed to remain open for e) time. Slabs on grade supporting heavy floor loads should at least six (G) inches of crushed gravel base course, moisture content and compacted to a minimum of ninety-f of Standard Proctor Density ASTMI 0 698-78.. (See Append and other areas transmitting light floor loads should N minimum of four (4) inches of clean gravel or crushed rc fines. The gravel base course and/or gravel will help to floor loads and will act as a capillary break. All slab should be designed for the imposed loading, and it is su: they be designed and constructed structurally independen members. To minirni7. era slabs on grade, we suggest that control joints be'placed (20) to twenty-five (25) feet and that the total area col these joints be no greater than six hundred twenty-five I feet. Pavements Preparation to pavement subgrade elevation should be, as previously discussed in the "Site Grading" section of AASHTO classification of the on -site near -surface nateria: pavement subgrade is A-6 with group indices 2 to 14. Usir index design procedure and a group index of 13, the follov thicknesses are recommended: 0 thousand (30,000) pounds per square foot. An estimated skin friction of three thousand (3000) pounds per square foot will be developed for that portion of the pier embedded into the firm bedrock stratum. To counter- act swelling pressures which will develop if the subsoils become wetted, all piers should be designed for a minimum dead load of ten thousand (10,000) pounds per square foot. Where this minimum dead load require- ment cannot be satisfied, skin friction from additional embedment into the firm bedrock should be used to resist uplift. All piers should be reinforced their full length to resist tensile stresses created by swelling pressures acting on the pier. It is essential that all grade beams have a minimum four (4) inch void between the bottom of, the beam. and the soil below: The anticipated settlement of piers under the above maximum loading should be negligible. Temporary casing of all pier holes may be required to prevent sloughing of the overburden materials and to permit dewatering prior to concreting. To facilitate, cleaning, dewatering, and inspection of piers, minimum twenty-four (24) inch diameter piers are recommended. It is recommended that qualified geotechnical personnel be present during drilling operations to identify and verify penetration into the firm bedrock, make certain that all piers are of proper diameter and plumbness and that they are thoroughly cleaned and dewatered, and ensure that reinforcing steel and concrete are properly placed. Basements and Slabs on.Grade The subsurface. conditions encountered at the site will permit exca i vations of basements if desired. We do recommend that the basement finished floor be placed at least three (3) feet above groundwater levels encountered in this investigation and a minimum of three (3) feet ' above the bedrock surface. Due to the shallow bedrock encountered in Borings 22 and 23, basement construction may not be feasible in the extreme southeast corner of the property. ,{ The subsurface conditions at the site will also permit conventional slab -on -grade construction. Preparation to slab -on -grade subgrade ele- - 7- tests should be taken daily to determine the degree of compaction being attained and compliance with project specifications. Foundations Based upon the subsurface conditions encountered at the site and the loads transmitted by the proposed construction, we recommend that all structures be supported by conventional continuous or isolated spread footings bearing in undisturbed natural soil or fill placed as recommended above. As on -site materials will be used for fill, struc- tural fill placed and compacted asrecommended above will have com- parable shear strength and bearing qualities to those of the in situ materials. Exterior footings should bear a minimum of thirty (30) inches below exterior finished grades for frost protection. The nature of the bearing soil should be verified by qualified geotechnical per- sonnel prior to placement of foundation concrete. Footings bearing at the above -recommended depths may be designed for a maximum allowable soil pressure. of one thousand five hundred (1500) pounds per square foot under dead plus maximum live loads. To resist swelling pressures which will develop if the subsoils become wetted, footings should be designed for a minimum dead load pressure of five, hundred (500) pounds per square foot. The anticipated settlement under the above -recommended maximum i pressures should not exceed three -fourths (3/4) inch. The overburden materials encountered at the site are plastic and 1 may be susceptible to swelling if they are allowed to dry below their in situ moisture levels and then are rewetted. Therefore, to prevent drying of the clay soils below their in -place moisture levels, foundation and building excavations should not be allowed to remain open for ex- tended periods of time. As an alternative, the proposed structures can be supported on straight -shaft drilled piers end bearing in the bedrock formation. Piers drilled a minimum of three (3) feet into the firm bedrock stratum may be designed for a maximum allowable end bearing pressure of thirty recommend that all fill in building and pavement areas be placed in horizontal six (6) to eight (3) inch lifts at two percent (2%) wet of optimum moisture content and compacted to a ininimum of ninety-five percent (95%) of Standard Proctor Density ASTM D 698-78. Fill placed in proposed greenbelt areas should be compacted to a minimum of ninety percent (90%) of Standard Proctor Density ASTM D 698-78. Where fill is placed on slopes greater than 4:1. horizontal benches should be cut in the slopes to insure integrity of the new fill on the existing slopes. For stability, we recommend that all cut and fill slopes be no steeper than 2:1; however, flatter slopes are suggested for ease of maintenance. Finished slopes should be seeded with native grasses to minimize erosion. All utility trenches extending four (4) feet or more into the upper soils should be excavated on slopes no steeper than 1:1. The bedrock may be excavated on vertical slopes. Excavation of the bedrock may require the use of heavy-duty construction equipment. Where utilities are excavated below groundwater, dewatering will be required during placement of pipe and backfilling to insure proper construction. All piping should be bedded to insure proper load distribution and to elim- inate breakage during the backfilling operations. aackfill placed in utility trenches in open and planted areas should be compacted in uniform lifts at optimum moisture to at least ninety percent (90%) of Standard Proctor Density ASTrt D 698-78 the full depth of the trench. The upper four (4) feet of backfill placed in utility trenches under roadways and paved areas should be compacted at or near optimum moisture to at least ninety-five percent (95%) of Stand- ard Proctor Density ASTM D 698-78, and the lower portion of these trenches should be compacted to at least ninety percent (90%) of Standard Proctor Density ASTH 0 698-78. Addition of moisture to and/or drying of the subsoils may be required to assure proper compaction. Proper placement of the bedrock as backfill may be difficult, as is discussed above. Qualified geotechnical personnel should be present during all phases of earthwork to observe stripping of the topsoil, scarification of the subgrade, and placement and compaction of fill. In -place density (1) Topsoil and Fill: Thickness of topsoil at test boring lo- cations varies from approximately six (6) to twelve (12) inches. The upper six (6) inches of the topsoil have been penetrated by root growth and organic matter and are not suitable for foundation bearing or as backfill material. Fill was encountered in Borings 23, 249 290 30, and 33 extending to depths one (1) to two (2) feet below present grades. The fill is primarily sandy silty clay with some fine gravel. The fill is not suitable for support of foundations. (2) Sandy Silty Clay: The topsoil and fill are underlain.by brown, tan and red sandy silty clay extending to the bedrock surface or the depths explored. Some fine gravel and seams and layers of silty sand and gravel were encountered within the sandy silty clay. The primary layers of silty sand and gravel are identified on the Log of Borings. The near -surface portions of the sandy silty clay are medium stiff to stiff and have moderate shear strength and bearing characteristics. With increased penetration into the sandy silty clay, the material becomes more moist and softer. The near -surface portions of the sandy silty clay also exhibit moderate swell potential upon wetting. (3) Siltstone-Sandstone Bedrock: The surface of interbedded silt - stone and sandstone bedrock was encountered in Borings 1, 8, 14, 20, 22, 23, and 28 at depths seven and one-half (7-1/2) to twenty-nine and one-half (29-1/2) feet below present grades. The upper one-half (1/2) to two (2) feet of the bedrock for- mation is weathered. The underlying interbedded siltstone and sandstone is firm and has good shear strength and bearing characteristics. (4) Groundwater: Water was encountered in Borings 1 through 4, 89 11, 129 149 159 189 20 through 22, and 28 at depths ten and SITE LOCATION AND DESCRIPTION The project site is located on the north side of Of McMurray Avenue, southeast of Fort Collins, Colorad cally, the site is situate in the southwest 1/4 of Sec' 7 North ' Range 68 West of the Sixth Prime Colorado. Meridian, Lai The project site is presently field. Slope and drainage rarean open, grass- and been constructed along the south property to the south. Fill has i been end dumped on property line adjacent ons f the ditches across the property have been ofil edsite in. and R so ,q the east of the site, has been paved. Property to the n sently being developed for residential use. Open fields west of the site. LABORATORY TESTS AND EXAPfINATIO;J Representative samples recovered in the test borings' for tests in the laboratory to determine their and engineering properties.physical Included ck moisture content, water Solublesulfates, Atterber limiin the test ts: unconfined compressive strength, consolidation characterise Potential, and swell -consolidation characteristics. Labors results are summarized in Appendix B. Hveem stabilometer tests are also being performed for pavement sections. The results of the Hveem tests will be upon completion. SOIL AND GROUNDWATER CONDITIONS The following are the characteristics of the primary so• encountered at the site. REPORT OF A GEOTECNNICAL INVESTIGATION SCOPE This report presents the results of a geotechnical investigation prepared for the proposed Golden !Meadows Neighborhood Center, Larimer County, Colorado. The investigation included test borings, laboratory testing, engineering evaluation, and preparation of this report. The purposes of the investigation were to determine subsurface conditions at the site and to provide recommendations for development of the site as influenced by the subsurface conditions. SITE INVESTIGATION Thirty-four (34) test borings were drilled at the site on October 19 2, and 30 1980. Locations of the test borings are shown on the Test Boring Location Plan included in Appendix A. The borings were advanced with continuous -flight augers to depths seven (7) to thirty-four (34) feet below present grades. Samples were recovered with two and one-half (2-1/2) inch Shelby tubes and the stand- ard penetration sample technique. During drilling, a field engineer.of Empire Laboratories, Inc. was present and made a continuous visual i inspection of soils encountered. Logs prepared from the field notes are included in Appendix A of this report. Indicated on the logs are the i primary strata encountered, locations of samples, and groundwater con- ditions. t P) TABLE OF CONTENTS Table of Contents .............................................. i Letter of Transmittal .......................................... Report...................'...................................... 1 Appendix A ..................................................... A-1 Test Boring Location Plan..........6...........0............. A-2 Key to Borings ................................................ A-3 Log of Borings ................................................ A-4 Appendix B..................................................... B-1 Consolidation Test Data................................0..... B-2 Summary of Test Results ...................................... B-7 REPORT OF A GEOTECHNICAL INVESTIGATION FOR ! ZVFK, ARCHITECTS/PLANNERS FORT COLLINS, COLORADO PROJECT NO. 4213-80 RE: GOLDEN.MEADOWS NEIGHBORHOOD CENTER LARIMER COUNTY, COLORADO BY EMPIRE LABORATORIES, INC. 214 NORTH HOWES STREET FORT COLLINS, COLORADO 80521 one-half (10-1/2) to sixteen (16) feet below present grades. No water was encountered in the remaining test borings at the time of this investigation. Groundwater levels at the site will fluctuate with seasonal variations and conditions. ANALYSIS AND RECOMMENDATIONS We understand that the Neighborhood Center will be developed for commercial use. The proposed buildings will be one- or two -stories with conventional slab -on -grade construction. A basement is proposed for the building to be constructed at the. southwest corner of the site. The following are our recommendations for development of .the site as influenced by the subsurface conditions encountered in the test borings. Site Grading We anticipate that some cutting and filling will be required on the; site to achieve desired finished grades. As building foundations and/or slabs on grade may be supported on fill, we recommend that fill place- ment be in accordance with FNA "Data Sheet 79G." The following are our recommendations for site grading and placement of compacted fill. The upper six (6) inches of all topsoil should be stripped in proposed cut and fill areas and in building and pavement areas which will remain at present grades. The topsoil can be stockpiled on the site and used for final grading outside of building and pavement areas. At cut subgrade elevation and in areas to receive fill, the upper six (6) inches of the subgrade should be scarified and recompacted at two percent (2%) wet of optimum moisture content to a minimum of ninety percent (90%) of Standard Proctor Density ASTM D 698-78. (See Appendix C.) The on -site overburden materials are suitable for use as fill in proposed building and pavement areas. Any additional off -site fill required should be a material approved by the geotechnical engineer. We Empire .-aaboratories, Inc. MATERIALS AND FOUNDATION ENGINEERS 214 No. Howes Fort Collins, Colorado 80522 P.O. Box 429 (303) 484-0359 October 17, 1980 ZVFK, Architects/Planners 218 West Mountain Avenue Fort Collins, Colorado 80521 Attention: Mr. Ed Zdenek Gentlemen: Branch ( 1242 Bramwooc Longmont, Colorado I P.O. Box (303) 776 3151 Nation Cheyenne, Wyoming £ P.O. Box 1 (307) 632 We are pleased to submit our Report of a Geotechnical Investigation prepared for the proposed Colden Meadows Neighborhood Center, Larimer County, Colorado. The subsurface conditions revealed by this investigation are suitable for the intended construction, provided construction is in accordance with the recommendations contained in this report. The attached report presents the subsurface conditions at the site and our recommendations for development of the site. We appreciate this opportunity of consulting with you on this project. If you have any questions or if we can be of further assistance, please contact us. Very truly yours, W- LABORAGsT.O�RIESvO INC. James E.Yeith, P.E. Geotechnical Engineer Reviewed by: %' 4�/ Chester C. Smith, P.E. President cic cc: Collindale South II - Bill Tiley MEMBER OF CONSULTING ENGINEERS COUNCIL ,Z�0%'4; -S E. VF' o�G ST 14