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Home My WebLink AboutSoils Report 10.13.2016LKPEngineering, Inc. } _� ^� CIVIL/GEOTECHNICAL �I I V I1 l� 1 API? 0 71017 SOIL AND FOUNDATION INVESTIGATION FOR A PROPOSED RESIDENCE LOT 4, WESTBANK RANCH PUD #4 RESUBDIVISION DOLORES CIRCLE GARFIELD COUNTY, COLORADO PROJECT NO. 16-3135 OCTOBER 13, 2016 I`'��►!glrl!!S4SI+�� PREPARED FOR: MELANIE ROSSOW 1512 MOUNTAIN DRIVE GLENWOOD SPRINGS, CO 81601 P.O. Box 724, Eagle, CO 81631 Tel (970) 926-9088 NVw•w-ikicnginccring.com 2 EXECUTIVE SUMMARY The proposed residence should be supported with conventional type spread footings, designed for an allowable soil bearing pressure of 1000 psf. They should construct the footings on the undisturbed brown, sandy to clayey silt. See Foundation Recommendations. SCOPE OF STUDY This report presents the results of a subsurface Soil and Foundation Investigation for a proposed residence to be constructed on Lot 4, Westbank Ranch PUD Filing No. 4, Dolores Circle, Garfield County, Colorado. The purpose of the subsurface soil and foundation investigation was to determine the engineering characteristics of the foundation soil and to provide recommendations for the foundation design, grading, and drainage. Geologic hazard studies are outside of our scope of services. SITE DESCRIPTION Lot 4 is 1.19 -acres parcel of land, located on the north side of the road on Dolores Circle, east from the intersection with Huebinger Drive. The property is south of Glenwood Springs in Garfield County, Colorado and is accessed from Colorado State Highway 82, to CR 154 (Old State Hwy 82) to Co Rd 109 to Huebringer and to Dolores Circle. The proposed building site is at LKP Engineering, Inc. 4 We sampled the soil in the test pits at random intervals. The soil samples were tested in our laboratory for swell -consolidation, natural dry density, and natural moisture content. The test results are shown on Figure No's 3 and 4. FOUNDATION RECOMMENDATIONS The proposed residence should be supported with conventional type spread footings, designed for a maximum allowable soil bearing pressure of 1000 psf. The footings should be constructed on the undisturbed light to reddish -brown, clayey to sandy silt. We recommend a minimum width of 16 inches for the continuous footings and 2 feet for the isolated footing pads. Continuous foundation walls should be reinforced top and bottom to span an unsupported length of at least 10 feet. The proposed foundation should be constructed below the frost depth, as regulated by the local building code. The foundation excavation should be observed by the undersigned engineer to ver0, that the soil conditions encountered during construction are as anticipated in this report. The foundation excavation should be free from excavation spoils, frost, organics and standing water. We recommend proof -rolling of the foundation excavation. Soft spots detected during the proof -rolling, should be removed by overexcavation. Any overexcavation within the proposed foundation should be backfilled, in 8 inches loose level lifts and compacted to 100% of the maximum dry density and within 2 percent of the optimum moisture content as determined in a laboratory from a Standard Proctor test (ASTM D-698). A structural fill, placed under footings should be tested by a qualified professional. SLAB CONSTRUCTION The natural on-site soils, exclusive of topsoil and organics, are suitable to support lightly LKP Engineering, Inc. 6 backfill surface. Surcharge loading due to adjacent structures, weight of temporary stored construction materials and equipment, inclined backfill and hydrostatic pressure due to undrained backfill should be incorporated in the design. They should prevent the buildup of hydrostatic pressure behind the retaining wall. UNDERDRAIN SYSTEM To reduce the risk of surface water infiltrating the foundation subsoil, installation of a foundation perimeter drain (see Figure No. 5). we recommend The foundation perimeter drain should consist of a 4 -inch diameter, perforated pipe, sloped to a suitable gravity outlet, or to a sump pump location, at a 1/4 inch per foot for flexible or at a 1/8 of an inch for rigid pipe. The bottom of the trench adjacent to the footing should be lined with a polyethylene moisture barrier glued to the foundation wall. The drain pipe should he covered with a minimum of 6 inches of -3/4-inch free -draining granular material. Geotextile (Mirafi 140N or equivalent) should be used to cover the free -draining gravel to prevent siltation and clogging of the drain. The backfill above the drain should be granular material to within 2 feet of the ground surface to prevent a buildup of hydrostatic pressure. SITE GRADING AND DRAINAGE The following recommendations are general. Exterior backfill should be compacted at or near the optimum moisture content to at least 95% of the maximum standard Proctor density under pavement, sidewalk and patio areas and to at least 90% of the maximum standard Proctor density under landscaped areas. They should use mechanical methods of compaction. Do not puddle the foundation excavation. The site surrounding the building structure should slope away from the building in all LKP Engineering, Inc. 8 There is no other warranty either expressed or implied. The findings and recommendations of this report are based on field exploration, laboratory testing of samples obtained at the specific locations shown on the Location Sketch, Drawing No.1 and on assumptions stated in the report. Soil conditions at other locations may vary, which may not become evident until the foundation excavation is completed. If soil or water conditions seem different from those described in this report we should be contacted immediately to reevaluate the recommendations of this report. We are not responsible for technical interpretation by others of the data presented in this report. This report has been prepared for the exclusive use of Melanie Rossow, for the specific application to the proposed residence Lot 4, Westbank Ranch PUD Filing No. 4, Dolores Circle, Garfield County, Colorado. Sincerely, LKP ENGINEERING, INC. Luiza Petrovska, PE J:\ WP X4-LKP\ 2016\16-3135SND-SLTPITS.DOCX �,•kp REQ' ��'1/4 if 29526 : cc w - ■ •c4., 0,{% o �� ''''''.?0810N ,rR1+\- LKP Engineering, Inc. DATE OBSERVED: OCTOBER 8. 2016 Test Pit O 1 ELEVATION: DEPTH FEET S Y M 8 O L S A M p L E DESCRIPTION OF MATERIAL AND SAMPLE LOCATION LABORATORY TEST RESULTS REMARKS - — — 5 10 15 I - _ = nem 4.•. •. • -,❑ Darker brown, blocky clayey, sandy silt with some topsoil and fine roots o Light to reddish -brown, sand to clayey silt DD= 95.1 pcf MC= 5.5 X DD= 93.5 pcf MC=8.3X Bottom of Test Pit ® 8 feet No Ground Water Encountered 20 LEGEND: ❑ - 2—Inch O.D. California Liner Sample ■ — Bulk Sample DD — Natural Dry Density (pcf) MC — Natural Moisture Content (X) —200 — Percent Passing No. 200 Sieve LL — Liquid Limit PI — Plasticity Index GW — Ground water LKP ENGINEERING, INC. SUBSURFACE EXPLORATION LOG ntO.ECT NO.: 16-3135 mu 1 2 0 •5 -2 W -4 k - 6 0 -1 2 0 - 2 -4 - 6 -12 t T b \\ -- 0.1 1 0 10 100 APPLIED PRESSURE - ksf Sample oFLight brown, sandy silt From: Test Pit 1 at 4 feet Natural Dry Unit Weight = 95.1 pcf Natural Moisture Content = 5.5 percent t b ik \\ 0.1 10 10 100 APPLIED PRESSURE - ksf Sample ofBrown-white, clayey -sandy silt From: Test Pit 1 of 8 feet Naturol Dry Unit Weight = 93.5 pcf Natural Moisture Content = 8.3 percent LKP Engineering, Inc. Swell — Consolidation Test Results FROZCT Na: 16-3135 inne Aa: 3 LOPE AWAY FROM BUILDING OVER BACKFILL WITH A MINIMUM OF ONE FOOT OF RELATIVELY IMPERVIOUS SOIL GRANULAR FILL L. FOOTING r 30 MIL MINIMUM THICKNESS, PLASTIC LINER, GLUED TO THE FOUNDATION WALL ILTER FABRIC (MIRAFI 140N OR EQUIVALENT) NUS 3/4 -INCH DIAMETER, COARSE, CLEAN CRUSH ROCK •INCH DIAMETER PERFORATED PIPE SLOPED TO A DAYLIGHT LOCATION AWAY FROM THE FOUNDATION AT 1/4 -INCH PER FOOT FOR FLEXIBLE AND 1/B -INCH MINIMUM FOR RIGID PIPE OR TO A SUMP PUMP PERIMETER DRAIN CIVIVGEOTECHNICAL PROJECT NO.: 15-3135 �1j LOT 4, WESTBANK RANCH PUD #4 RESUB �,LKP Engineering, Inc. DOLORES CIRCLE, GLENWOOD SPRINGS SCALE: N.T.S. P O. Box 724 Eagle, Co 81631 GARFIELD COUNTY, COLORADO FIGURE NO: Tel.(970) 926-9088 5