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Home My WebLink AboutExcavation ObservationH EPWORTH - PAWLAK GEOTECHNICAL September 20, 2012 Personal Home Care Company Attn: David Faulkenberg 1853 Cooley Mesa Road Gypsum, Colorado 81637 Faulkenbe gr 4 �,ginail.com SI1 I I.f I[11_ l Ic;l, . .,f , 3'3n,,,. t'..1,1.1 I Job No. 112 202A Subject: Excavation Observation, Proposed Bachman Residence, Lot 9A, Elk Valley Estates, County Road 241, Garfield County, Colorado Dear David: As requested, a representative of Hepworth-Pawlak Geotechnical observed the excavation at the subject site on September 19, 2012 to evaluate the soils exposed for foundation support. We also tested structural fill placed below the proposed building footing areas on a part-time basis. The findings of our observations and test results with respect to the foundation design are presented in this report. We previously conducted a subsoil study for design of foundations at the site and presented our findings in a report dated July 19, 2012, Job No. 112 202A. The proposed construction is similar to that discussed in our previous report. The foundation design consists of spread footings bearing on 3 feet of compacted structural fill using an allowable soil bearing pressure of 2,000 psf, based on recommendations provided in our subsoil study report. Between September 6 and 12, 2012 we tested compaction of the onsite soils moisture conditioned and placed below the proposed footing areas of the building on a part -tune basis. The results of laboratory Proctor testing performed on a sample of the onsite soils used as structural flI are provided on Figures 1 and 1A. The compaction test results are also attached and the results indicate the soils were compacted to a minimum 98% standard Proctor density as recommended. On September 19, we observed the completed foundation excavation to have been cut in several levels from about 2V2 to 10 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation footing areas consisted of the compacted on-site Rifker 10 3 1 -7119 ® Cult)ra t 3 prii s 7 1 q -C, 3 1-5 56. 4 Silver dW970-46ti- 1 9 tl -2 - structural fill. No free water was encountered in the excavation and the soils were generally moist. The soil conditions exposed in the excavation are consistent with those previously encountered on the site and structural fill properly placed and compacted, and suitable for support of spread footings designed for the recommended allowable bearing pressure of 2,000 psf. There is some risk of foundation settlement if the underlying natural bearing soils become wetted as discussed in our previous report. Prior to the footing construction, any loose disturbed soils should be removed and the subgrade re -compacted as needed. Other reconnrnendations presented in our previous report which are applicable should also be observed. The recommendations submitted in this letter are based on our observation of the soils exposed within the foundation excavation and the previous subsurface exploration at the site. Variations in the subsurface conditions below the excavation could increase the risk of foundation movement. We should be advised of any variations encountered in the excavation conditions for possible changes to recommendations contained in this letter. If you have any questions or need further assistance, please call our office. Sincerely, HEPWORTH — PAWLAK GEOTECHNICAL, INC. •� is s• °tl.�°e' ... y, og'y 1�. lz n o u _ David A. Young, PS. Ale attachments Figure 1, Laboratory Proctor Test Results Daily Field Compaction Reports for September 6, 10, 11 and 12, 2012 DAY/ksw Job No. 112 202A G14iteCh HEPWORTH-PAWLAK GEOTECHNICAL 5020 County Road 154 Glenwood Springs, Colorado 81601 Phone: 970-945-7988 Fax: 970-945-8454 hpgeoAhpgeolech.com Earthwork Compaction Testing Report Client: Personal Home Care Company Job No.: 112 202A Day: Thursday Attn: David Faulkenberg Date: 916112 1853 Cooley Mesa Road Page: 1 of 1 Gypsum, Colorado 81637 Bachman Residence, Lot 9A, Elk Valley Estates, County Road 241, East Elk Creek, Garfield County, Colorado Project: Weather: Cloudy, calm, dry Temperature: 86° at 3:30 pm Earthwork Contractor: Miles Rippy Excavation Equipment Used: trackhoe, loader, vibratory sheeps foot roller, vibratory double drum walk behind Description of Earthwork Structural fill below footings; the contractor had excavated a small portion of Tested: the northwest corner of the garage footing area and backfilled 3' depth of material. We performed compaction density testing at backfilled area. Based on our test results compaction was judged to be adequate. Sample(s) Obtained: We obtained a sample of on site soils material for laboratory Proctor testing (see Figures 1 and 1A). Verbal Communication: Miles Rippy Excavation was informed of our test results. Placement and Compaction Procedure: Not observed by HP Geotech. Lift Thickness: 18" Max. Rock Size: Moisture at stockpile Conditioning: Compactor(s) Used: vibratory sheeps foot roller, vibratory Number of Passes: double drum walk behind Nuclear Gauge Moisture/Density Test Results Test No. Location Structural Fill Below Garage Footings Depth or Elev. Field Dry Density (pct) Field Moisture Content % Field Comp. (%) Min. Comp. Req. (%) Proctor Lab No. 1 NW corner of garage ftg grade 118.7 11.5 99 Proctor Sample Reference: 98 L. 252-12 Lab No. Method Description Max. Dry Dens. (%) _ Opt. Moist. (%) 10.7 252-12 ASTM D 698 Clayey Silty Sand and Gravel with Cobbles 119.3 THIS REPORT PRESENTS OPINIONS AS A RESULT OF OUR OBSERVATIONSOF FILL PLACEMENT, WE HAVE RELIED ON THE CONTRACTOR TO CONTINUE APPLYING THE RECOMMENDED COMPACTIVE EFFORT AND MOISTURE TO FILL DURING THE TIMES WHEN OUR OBSERVER IS NOT OBSERVING OPERATIONS. THE NUCLEAR DENSOMETER METHOD OF TESTING WAS USED IN SUBSTANTIAL ACCORDANCE WITH ASTM D 6938. Distribution: Personal Home Care Company — David Faulkenberg (faulkenberg4c gamlf.com) Justin Orgill David A. Young, P.E. Field Technician lksw Reviewed By G&ech HEPWORTH-PAWLAK GEOTECHNICAL 5020 County Road 164 Glenwood Springs, Colorado 81601 Phone: 970-945-7988 Fax: 970-945-8454 hpgeoPa.hpgeotech.com Earthwork Compaction Testing Report Client: Personal Home Care Company Job No.: Attn: David Faulkenberg 1853 Cooley Mesa Road Gypsum, Colorado 81637 Project: Bachman Residence, Lot 9A, Elk Valley Estates, County Road 241, East Elk Creek, Garfield County, Colorado 112 202A Day: Date: Page: Monday 9/10/12 1 of 1 Weather: Cloudy, light wind, dry Temperature: 86° at 1:00 pm Earthwork Contractor: Miles Rippy Excavation Equipment Used: Description of Earthwork Tested: Verbal Communication: trackhoe, backhoe, vibratory sheeps foot roller, vibratory double drum walk behind Structural fill below footings; we performed compaction testing at structural fill for below building footings. Based on our test results compaction was judged to be adequate. Miles Rippy Excavation was informed of our test results. Placement and Compaction Procedure: Not observed by HP Geotech. Lift Thickness: 12-18" Max. Rock Size: Compactor(s) Used: vibratory sheeps foot roller, vibratory double drum walk behind Moisture Conditioning: Number of Passes: at stockpile Nuclear Gauge Moisture/Density Test Results Test No. Location Structural Fill below Residence Footings Depth or Elev. Field Dry Density (pcf) Field Moisture Content Field Comp. (%) Min. Comp. Req. (%) Proctor Lab No. 1 30' S of NW corner of basement 2' below ft rade 118.1 12.7 99 98 252-12 2 10' s of NW corner of basement 3 SW corner of garage 1' below ft9 grade 119.9 '12.4 100 98 252-12 ftg grade 119.0 13.1 100 98 252-12 Proctor Sample Reference: Lab No. Method Description Max. Dry Dens. (%) Opt. Moist. (cY2) 252-12 ASTM D 698 Clayey Silty Sand and Gravel with Cobbles 119.3 10.7 THIS REPORT PRESENTS OPINIONS AS A RESULT OF OUR OBSERVATIONSOF FILL PLACEMENT, WE HAVE RELIED ON 7HE CONTRACTOR TO CONTINUE APPLYING THE RECOMMENDED COMPACTIVE EFFORT AND MOISTURE TO FILL DURING THE TIMES WHEN OUR OBSERVER IS NOT OBSERVING OPERATIONS. THE NUCLEAR DENSOMETER METHOD OF TESTING WAS USED IN SUBSTANTIAL ACCORDANCE WITH ASTM D 6938. Distribution: Personal Home Care Company— David Faulkenberg (faulkenberg4 vestrnail.com) Justin Orgill David A. Young, P.E. Field Technician Reviewed By /ksw GLIZ HEPWORTTH -PAWLAK GEOTECHNICAL 6020 County Road 154 Glenwood Springs, Colorado 81601 Phone: 970-945-7988 Fax: 970-945-8454 hpgeo(r hpgeotech.com Earthwork Compaction Testing Report Client: Personal Home Care Company Job No.: Attn: David Faulkenberg 1853 Cooley Mesa Road Gypsum, Colorado 81637 Project: Bachman Residence, Lot 9A, Elk Valley Estates, County Road 241, East Elk Creek, Garfield County, Colorado 112 202A Day: Tuesday Date: 9/11/12 Page: 1 of 1 Weather: Cloudy, calm, dry Temperature: 74° at 12:00 pm Earthwork Contractor: Miles Rippy Excavation Equipment Used: Description of Earthwork Tested: Verbal Communication: trackhoe, backhoe, vibratory sheeps foot roller, vibratory double drum walk behind Structural fill below footings; we performed compaction testing on structural fill below building footings. Based on our test results compaction was judged to be adequate. Miles Rippy Excavation was informed of our test results. Placement and Compaction Procedure: Not observed by HP Geotech. Lift Thickness: 12-18" Max. Rock Size: Compactor(s) Used: vibratory sheeps foot roller, vibratory double drum walk behind Moisture at stockpile Conditioning: Number of Passes: Test No. Location Nuclear Gage Moisture!DensitvTest Results Structural Fill Below Residence Footings Depth or Elev. Field Dry Density (pcf) Field Moisture Content Field Comp. (%) Min. Comp. Req. (%) Proctor Lab No. 1 NW corner of basement 18" below ftg grade 118.6 14.8 99 98 262-12 2 30' S of NW corner of basement ftg grade 119.5 12.7 100 98 252-12 3 SE corner of basement 2' below ftg grade 119.2 12.8 100 98 252-12 Proctor Sample Reference: Lab No. Method Description Max. Dry Dens. (%) Opt. Moist. (%) 252-12 ASTM D 698 Clayey Silty Sand and Gravel with Cobbles 119.3 10.7 THIS REPORT PRESENTS OPINIONS AS A RESULT OF OUR OBSERVATIONSOF FILL PLACEMENT, WE HAVE RELIED ON THE CONTRACTOR TO CONTINUE APPLYING THE RECOMMENDED COMPACTIVE EFFORT AND MOISTURE TO FILL DURING THE TIMES WHEN OUR OBSERVER IS NOT OBSERVING OPERATIONS. THE NUCLEAR DENSOMETER METHOD OF TESTING WAS USED IN SUBSTANTIAL ACCORDANCE WITH ASTM D 6938. Distribution: Personal Home Care Company—David Faulkenberg gaulkenberg4t gmail.com) Justin Orgill David A. Young, P.E. Field Technician Reviewed By Iksw Gea HEPWORTH-PAWLAK GEOTECHNICAL 5020 County Road 154 Glenwood Springs, Colorado 81601 Phone: 970-945-7988 Fax: 970-945.8454 h pgeoAhocteotech .com Earthwork Compaction Testing Report Client: Personal Home Care Company Job No.: Attn: David Faulkenberg 1853 Cooley Mesa Road Gypsum, Colorado 81637 Project: Bachman Residence, Lot 9A, Elk Valley Estates, County Road 241, East Elk Creek, Garfield County, Colorado 112 202A Day: Date: Page: Wednesday 9112/12 1 of 1 Weather: Partly cloudy, light wind, dry Temperature: 76° at 1:30 pm Earthwork Contractor: Miles Rippy Excavation Equipment Used: Description of Earthwork Tested: Verbal Communication: trackhoe, backhoe, vibratory sheeps foot roller, vibratory double drum walk behind Structural fill below footings; we performed compaction testing on structural fill for below building footings. Based on our test results compaction was judged to be adequate. Miles Rippy Excavation was informed of our test results. Placement and Compaction Procedure: Not observed by HP Geotech. Lift Thickness: 12-18" Compactor(s) Used: Max. Rock Size: vibratory sheeps foot roller, vibratory double drum walk behind Moisture Conditioning: Number of Passes: at stockpile Test No. Location Nuclear Gauge Moisture/Density Test Results Structural Fill Below Residence Footings Depth or Elev. Field Dry Density (pcf) Field Moisture Content Field Comp. (%) Min. Comp. Req. (%) Proctor Lab No. 1 6' Nof SE corner of basement ftg grade 118.4 14.6 99 98 252-12 2 30' N of SE corner of basement 18" below ftg grade 118.9 14.4 100 98 252-12 3 stair pad ftg grade 118.6 12.6 99 98 252-12 Proctor Sample Reference: Lab No. Method Description Max. Dry Dens. (%) Opt. Moist. (%) 252.12 ASTM D 698 Cla e Silty Sand and Gravel with Cobbles 119.3 10.7 THIS REPORT PRESENTS OPINIONS AS A RESULT OF OUR OBSERVATIONSOF FILL PLACEMENT, WE HAVE RELIED ON THE CONTRACTOR TO CONTINUE APPLYING THE RECOMMENDED COMPACTIVE EFFORT ANL/ MOISTURE TO FILL DURING THE TIMES WHEN OUR OBSERVER IS NOT OBSERVING OPERATIONS. THE NUCLEAR DENSOMETER METHOD OF TESTING WAS USED IN SUBSTANTIAL ACCORDANCE WITH ASTM D 6938. Distribution: Personal Home Care Company — David Faulkenberg (faulkenberg4@gmaiLcom) Justin Orgill David A. Young, P.L. Field Technician Reviewed By /ksw Laboratory Proctor Compaction Test Report 1211■■■■U ■■■■■.■■■■■■■■■■ ■= `` MI ■■■■■■■■■■■■■■ ■E■E■l� MIME= ■■RM■■■■MMURE MEMR■■■• Immum ■■■■■■.■■■■■■■■■M 120 Emum ■02 Aimmum■■ ■■ni;■■■■■■■ 4 MM a ■■■■■■p..i� ■■■■■■r■■IEE■ ■■■■ MM . 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Sp.G- LL PI % > 314 in. °1° < No.200 USCS AASHTO SC A-4(0) 30 8 18 37 ROCK CORRECTED TEST RESULTS UNCORRECTED MATERIAL DESCRIPTION Maximum dry density = 119.3 pcf Optimum moisture = 10.7 % 112.7 pcf 12.9 Clayey Silty Sand and Gravel with Cobbles Project No. 112202A Client: Personal Home Care Company Project: Bachman Residence, Lot 9A, Elk Valley Estates, County Road 241, East Elk Creek, Garfield County, CO o Source of Sample: On Site Soils Sample Number: 252-12 Remarks: See Figure 1A for Gradation Results Figure 1 Hepworth-Pawlak Geotechnical, Inc. Glenwood Springs, Colorado Tested By: MY Checked By: JP PERCENT FINER 100 90 80 70 60 50 40 30 20 10 Particle Size Distribution Report 100 I0 GRAIN SIZE - mm. 01 0.01 0.001 % #3" % Gravel % Sand % Fines Coarse Fine Coarse Medium Fine Sift Clay 4 14 15 3 8 19 37 SIEVE SIZE PERCENT FINER SPEC." PERCENT PASS? ()DENO) 5 100 3 96 1.5 9I .75 82 .375 73 #4 67 #8 64 #16 62 #30 58 #50 54 #100 45 #200 37 (no specification provided) Source of Sample: On Site Soils Sample Number: 252-12 Hepworth-Pawlak Geotechnical, Inc. Glenwood S • rin • s Colorado Tested By; MY Mater al Description Clayey Silty Sand and Gravel with Cobbles PL= 22 Dg0= 35;9714 D50= 0.2245 D10= USCS= SC Atterberg Limits LL= 30 Coefficients D$5= 24.3368 D30= Cu-. Classification AASHTO= A-4(0) Remarks Sec Figure 1 for Standard Compaction Results PI= 8 060= 0.8211 D15= CC= Date: 9-12-12 Client; Personal Home Care Company Project: Bachman Residence, Lot 9A, Elk Valley Estates, County Road 241, East Elk Creek, Garfield County, CO Pro ect No: 112202A Fh ure IA Checked By: JP