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Home My WebLink AboutExcavation Observation Report 06.03.2015June 3, 2015 Silich Construction Inc. Attn: Hayden lorsford 303 AABC, Suite J Aspen, Colorado 81612 (Ithorsford(i !siIichconstruction.com) Job No. 115 066D Subject: Observation of Excavation, Proposed Residence, Lot 293, Ironbridge Development, River Bend Way, Garfield County, Colorado Gentlemen: As requested by Hayden Horsford with Silich Construction. a representative of Hepworth-Pawlak Geotechnical, Inc. observed the building excavation and performed compaction testing on May 28, 29, June 1, 2 and 3, 2015 at the subject site to document the soil conditions exposed for foundation support. The findings of our observations and testing, and recommendations for 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 April 30, 2015, Job No. 113 471L. The proposed residence is essentially the same as described in our previous report and will be supported on spread footings placed on compacted structural fill in the shallow footing, garage and porch areas and on the natural soils in the basement cut area and sized for an allowable bearing pressure of 1,000 psf. At the time of our site visits on May 28 through June 3, 2015, we observed excavation and backfill, and tested compaction of the backfill below the shallow footing areas in the back porch and garage. The compaction testing results are presented in the attached Earthwork Compaction Testing Reports and indicate acceptable compaction. The basement area excavation was cut in one level from 8 to 9 feet below the adjacent ground surface. The soils exposed in the bottom of the excavation consisted of sandy silt. The exploratory boring drilled on the lot for the previous study showed the silt soils to extend to about 9 feet below basement cut depth and overlie dense river gravel soils. The basement cut level was compacted concurrent with the backfill placement in the garage and porch areas. No free water was encountered in the excavation and the soils were generally moist. The natural soils and compacted soils exposed in the excavation are consistent with those expected at the site and suitable for support of spread footings designed for the recommended allowable bearing pressure of 1,000 psf with the risk of settlement. Any remaining loose disturbed soils should be compacted in the footing areas prior to concrete Silich Construction Inc. June 3, 2015 Page 2 placement. Other recommendations presented in our previous report which are applicable, especially those to keep the bearing soils dry, 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 limited 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. Our services do not include determining the presence, prevention or possibility of mold or other biological contaminants (MOBC) developing in the future. If the client is concerned about MOBC, then a professional in this special field of practice should be consulted. If you have any questions or need further assistance, please call our office. Sincerely, f-IEPWORTH — PAWLAK GEOTECHNICAL. INC. Thomas J. Westhoff, CET RCN,iewed By: Steven L. Pawlak, P.1✓. TJW. k.sw Attachments: Earthwork t 44. 15222 a • r, °pl�r0 ":ng Reports (5 pages) cr : Aspen Signature I-loines of Ironbridge, LLC Llwyd Ecclestone (IeeeIe'tone c,^ 1�blhll.net) Silich Construction -.John Silich(jc,liii((thiliclil:t,il•truetion.LoIU) Silich Homes -• Jodi 1 himsen ( 10(11 a siliLtihi,rnes.cc.rm) lot) No 115(166D Gtech i Gtech HEPWORTH -PAWLAK GEOTECHNICAL 5020 County Road 154 Glenwood Springs, Colorado 81601 Phone: 970-945-7988 Fax: 970-945-8454 prnoahngem,cli CCF Earthwork Compaction Testing Report Client: Silich Construction Inc. Job No.: Attn: Hayden Horsford 303 AABC, Suite J Aspen, Colorado 81611 Proposed Residence, Lot 293, Ironbridge Development, River Bend Way, Garfield County, Colorado Project: 115 066D Day: Date: Page: Thursday 5128115 1 of 1 Weather: Partly cloudy, calm, dry Temperature: 69° at 3:00 pm Earthwork Contractor: Equipment Used: Description of Earthwork Tested: Verbal Communication: Linkbelt 210 track hoe, Wacker RT remote double drum roller The back porch footing area was sub -excavated a total of 7 feet below design footing grade. The sub -excavation was deepened an additional 2 feet below design cut depths because of wet and soft soils encountered in the footing area. Backfill of the footing area was then started. We observed and tested 4 lifts placed today. Tests indicated acceptable compaction referencing Proctor from Lot 292 next door, our Job No. 113471H. The track hoe operator was informed of our test results. Placement & Compaction Procedure: Observed by HP Geotech. Lift Thickness: 1 foot Max. Rock Size: 3/4" Compactor(s) Used: Wacker RT remote double drum roller Moisture natural Conditioning: Number of Passes: 8 to 10 Nuclear Gauge Moisture/Density Test Results Test No. Location Back Porch Footing Area Depth or Elev. Field Dry Density (pcf) Field Moisture Content ok Field Comp. (%) Min. Comp. Req. (%) Proctor Lab No. 1 15' N, 5' E of SW Lot corner 5' below footing grade 112.1 13.4 98 98 006-15 2 12' N, 6' E of SW Lot corner 4' below footing grade 117.4 13.4 102 98 006-15 3 10' N of SW Lot corner 3' below footing grade 114.0 12.1 99 98 006-15 4 15' N of SW Lot corner 2' below footing grade 113.9 12.6 99 98 006-15 Proctor Sample Reference: Lab No. Method Description Max. Dry Dens. pcf Opt. 7 Moist. (%) 006-15 1113471H} ASTM D 698 Sandy Silt 114.9 12.3 THIS REPORT PRESENTS OPINIONS AS A RESULT OF OUR CESERVATIONSOF FILL PLACEMENT WE. HAVE RELIED ON TH z i.' }tJl RAC IOR TO CONTINUE APFLYIIJG THE RECOMMEtJDE COt. PACTJVE EFF;;IRT AND MOISTURE TO FILL DURING THE 7I1.IES WHEN OUR DESERVER S NOT OBSERVfNG :PERAT`ONS THE NU: LEAR CEMO'.IETER METHOD OF TESTING WAS USED IN SUBSTANTIAL ACCORDANCE WITH ASTM Distribution: Aspen Signature Homes of Ironbridge, LLC - Llwyd Ecclestone (tecclostono n pbIhfi.net) Silich Construction — Hayden Horsford(hharsfordPsilichconstruction.com) TJW/ Thomas J. Westhoff, CET Field Technician Steven L. Pawlak, P.E. Reviewed By Geotech HEPWORTH-PAWLAK GEOTECHNICAL Client: Attn: Project: OULU ..uu ity mum! 134 Glenwood Springs, Colorado 81601 Phone: 970-945-7988 Fax: 970-945.8454 hpgeo(° hooaotech.com Earthwork Compaction Testing Report Silich Construction Inc. Job No.: 115 066D Day: Friday Hayden Horsford Date: 5/29/15 303 AABC, Suite J Page: 1 of 1 Aspen, Colorado 81611 Proposed Residence, Lot 293, lronbridge Development, River Bend Way, Garfield County, Colorado Weather: Partly cloudy, calm, dry Temperature: 46° at 8:30 am, 70° at 1:40 pm Earthwork Contractor: Equipment Used: Description of Earthwork Tested: Verbal Communication: Linkbelt 210 track hoe, Wacker RT remote double drum roller The back porch footing area backfill was completed to design footing grade. Two tests were performed during our morning site visit at porch footing grade with acceptable results. The basement portion of the excavation was then completed and the garage area was sub -excavated to 5 feet below design footing grade and compacted. Backfill of the garage footing area was then started. The first lift placed in the garage area was tested with acceptable compaction results and moisture contents ranging from 3.3 to 4.5% below optimum. The track hoe operator was informed of our test results. He stated that he would discontinue backfill placement until his water truck was available, expected to be Monday, 6!1/15. Placement & Compaction Procedure: Observed by HP Geotech. Lift Thickness: 1 foot Max. Rock Size: 2" Compactor(s) Used; Wacker RT remote double drum roller Moisture natural Conditioning: Number of Passes: 8 to 10 Nuclear Gauge Moisture/Density Test Results Test No. Location Depth or Elev. Field Dry Density (pcf) Field Moisture Content Field Comp. (%) 1 2' S of NW corner of back porch footing footing grade 112.4 13.6 98 Min. Comp. Req. (%) 98 Proctor Lab No. 006-15 2 1' N, 1' E of SW corner of back porch footing footing grade 112.5 13.0 98 98 006.15 3 Garage area, NE corner 4' below footing grade 116.1 7.8 101 98 006-15 4 Garage area, SW corner 4' below footing grade 112.4 9.0 98 98 006-15 Proctor Sample Reference: Lab No. Method Description Max. Dry Dens. pcf Opt. Moist. (%) 006-15 (113471H) ASTM D 698 Sandy Silt 114.9 12.3 7}115 REPDRT PRESENTS OPINIONS AS A RESULT OF OUR OBSERVATIONSOF FILL PLACEMENT. W E HAVE RELIED ON THE CON@ RACTOR 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 06933. Distribution: Aspen Signature Homes of Ironbridge, LLC - Llwyd Ecclestone (lecclestone(5 pbfhfl.net) Silich Construction — Hayden Horsford (hhorsford Wsilichconstruction.com) TJW/ Thomas J. Westhoff, CET Steven L. Pawlak, P.E. Field Technician Reviewed By Gtech HEPWORTH-PAWLAK GEOTECHNICAL Client: Attn: Project Glenwood Springs, Colorado 81601 Phone: 970-945-7988 Fax: 970-945-8454 hoaeo(5 hDgeotech.cam Earthwork Compaction Testing Report Silich Construction Inc. Job No.: 115 066D Day: Monday Hayden Horsford Date: 6/1/15 303 AABC, Suite J Page: 1 of 1 Aspen, Colorado 81611 Proposed Residence, Lot 293, Ironbridge Development, River Bend Way, Garfield County, Colorado Weather: Clear, light wind, dry Temperature: 83° at 4:45 pm Earthwork Contractor: Logan Equipment Used: Description of Earthwork Tested: Verbal Communication: Linkbelt 210 track hoe, Wacker RT remote double drum roller The garage area backfill below footings continued in the late afternoon. The second lift placed in the garage area was tested with acceptable compaction results and moisture contents slightly below optimum. Logan, the track hoe operator was informed of our test results. Placement & Compaction Procedure: Observed by HP Geotech. Lift Thickness: 1 foot max Max. Rock Size: 8" Compactor(s) Used. Wacker RT remote double drum roller Moisture Water truck with hose Conditioning: mixing in stockpile Number of Passes: 8 to 10 Test No. Location Nuclear Gauge Moisture/Density Test Results Garage area backfill below footing grade Depth or Elev. Field Dry Density (pcf) Field Moisture Content ok Field Comp. (%) Min. Comp. Req. (%) Proctor Lab No. 1 20' 5, 6' W of excavation NE corner 3.5' below footing grade 118.1 11.9 103 98 006-15 2 10' 5, 15' W of excavation NE corner 3.5' below footing grade 114.0 11.4 99 98 006-15 Proctor Sample Reference: Lab No. Method Description Max. Dry Dens. pcf Opt. Moist. (%) 006-15 (113471H) ASTM D 698 Sandy Silt 114.9 12.3 THIS REPORT PRESENTS OPINIONS AS A RESULT OF OUR OL3SERVATIONSOF FILL PLACEMENT. WE HAVE RELIED ON THE CONTRACTOR TO CONTINUE APPLYING TFIE RECOMMENDED COMPACTWE EFFORT ANO MOISTURE TO FILL DURING THE TIMES WHEN OUR OBSERVER S NOT OBSERVING OPERATIONS. THE NUCLEAR DENSOMETER METHOD OF TESTING WAS USED IN SUBSTANTIAL ACCORDANCE WITH ASTM 0 6938. Distribution: Aspen Signature Homes of Ironbridge, LLC - Llwyd Ecclestone (lecclestone(8 oblhf.net) Silich Construction — Hayden Horsford(hhorsfordOsilichconstruction.com) TJwr Thomas J. Westhoff, CET Steven L. Pawlak, P.E. Field Technician Reviewed By Gtech HEPWORTH - PAWLAK GEOTECHNICAL Glenwood Springs, Colorado 81601 Phone: 970.945-7988 Fax: 970.945-8454 hpaeoCa?hpgeotech.com Earthwork Compaction Testing Report Client: Silich Construction Inc. Job No.: 115 066D Day: Tuesday Attn: Hayden Horsford Date: 6/2/15 303 AABC, Suite J Page: 1 of 1 Aspen, Colorado 81611 Proposed Residence, Lot 293, Ironbridge Development, River Bend Way, Garfield County, Colorado Project: Weather: Clear, calm, dry Temperature: 69° at 10:00 am, 81° at 1:30 pm Earthwork Contractor: Logan Equipment Used: Description of Earthwork Tested: Verbal Communication: Linkbelt 210 track hoe, Wacker RT remote double drum roller Garage area backfill below footings continued. Three site visits were made for testing. Each lift was compacted and tested until acceptable compaction results were obtained. Moisture contents were slightly below optimum. Logan, the track hoe operator was informed of our test results. Placement & Compaction Procedure: Observed by HP Geotech. Lift Thickness: 1 foot max Max. Rock Size: 8" Compactor(s) Used: Wacker RT remote double drum roller Moisture Water truck with hose Conditioning: mixing in stockpile Number of Passes: 8 to 10 Nuclear Gauge Moisture/Density Test Results Test No. Location Garage area backfill below footing grade Depth or Elev. Field Dry Density (pcf) Field Moisture Content Field Comp. (%) Min. Comp. Req. (%) Proctor Lab No. 1 10' N, 5' W of excavation SE corner 3' below footing grade 108.0 10.8 94 98 006-15 1A Retest of #1 above 3' below footing grade 115.0 10.8 100 98 006-15 2 4' 8, 15' W of excavation NE corner 2' below footing grade 114.4 100 98 006-15 3 10' W, 5' N of excavation SE corner 1.5' below footing grade 110.1 11.5 96 98 006-15 3A Retest of #3 above 1.5' below footing grade 113.1 10.9 99 98 006-15 4 10' N, 10' W of excavation SE corner 0.5' below footing grade 118.0 11.3 103 98 006-15 5 15' S, 18' W of excavation NE corner 0.5' below footing grade 115.6 12.1 100 98 006-15 octor Sample Reference: Lab No. Method Description Max. Dry Dens. pcf Opt. Moist. (%) 006-15 (113471H) ASTM D 698 Sandy Silt 114.9 12.3 THIS REPORT PRESENTS OPINIONS AS A RESULT OF OUR OBSERVATIONSOF FILL PINCEMENT, WE HAVE RELIED ON THE G( COMPACTIVE EFFORT AND MOISTURE TD FILL DURING THE TIMES WHEN OUR OBSERVER 1S NOT OBSERVING OPERATIONS. TILE NUCLEAR DENSOMETER METHOD QF TESTING WAS USED IN SUBSTANTIAL ACCORDANCE WITH ASTM D 6938. Distribution: Aspen Signature Homes of Ironbridge, LLC - Llwyd Ecclestone (lecctestoneOpblhf.net) Silich Construction — Hayden Horsford (hhorsford( silichconstruction.com) TJW/ Thomas J. Westhoff, CET Steven L. Pawlak, P.E. Field Technician Reviewed By G&itech HEPWORTH -PAWLAK GEOTECHNICAL 5U211 County Road 154 Glenwood Springs, Colorado 81601 Phone: 970.945-7988 Fax: 970-945-8454 hpgeoCalhooeotech.com Earthwork Compaction Testing Report Client: Silich Construction Inc. Job No.: Attn: Hayden Horsford 303 AABC, Suite J Aspen, Colorado 81611 Project: Proposed Residence, Lot 293, Ironbridge Development, River Bend Way, Garfield County, Colorado 115 06613 Day: Date: Page: Wednesday 6/3/15 1 of 1 Weather Clear, calm, dry Temperature: 440 at 7:10 am Earthwork Contractor: Logan Equipment Used: Linkbelt 210 track hoe, Wacker RT remote double drum roller Description of Earthwork Garage area backfill below footings was completed and form work was in Tested: progress. Tests indicated acceptable compaction results were obtained. Backfill was completed yesterday and so moisture contents were about 3 percent below optimum at the time of testing. Verbal Communication: Forming crew was informed of that test results were acceptable. Placement & Compaction Procedure: Not observed by HP Geotech. Lift Thickness: 0.5 foot max Max. Rock Size: 4" Compactor(s) Used: Wacker RT remote double drum roller Moisture Water truck with hose Conditioning: mixing in stockpile Number of Passes: Not observed Nuclear Gauge MoisturelDensit Test Results Test No. Location Garage area backfill below footing grade Depth or Elev. Field Dry Density (pcf) Field Moisture Content %o Field Comp. (%) Min. Comp. Req. (%) Proctor Lab No. 1 Center of east garage footing footing grade 120.8 9.3 105 98 006-15 2 6' W of garage SE corner footing grade 115.8 8.7 100 98 006-15 Proctor Sample Reference: Lab No. Method Description Max. Dry Dens. pcf Opt. Moist. (%) 006-15 (113471H) ASTM D 698 Sandy Silt 114.9 12.3 THIS REPORT PRESENTS OPINIONS AS A RESULT OF OUR OBSERVATIONSOF FILL PLACEMENT, WE RAVE 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 DENSPMETER METHOD OF TESTING WAS USED IN SUBSTANTIALACCORDANCE WITH ASTM D 698. Distribution: Aspen Signature Homes of Ironbridge, LLC - Llwyd Ecclestone (Iecclestone0pblhfl.net) Silich Construction — Hayden Horsford(hhorsfordOsilichconstruction.com) TJW/ Thomas J. Westhoff, CET Steven L. Pawlak, P.E. Field Technician Reviewed By