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Liu-Field Report.pdfFEB-2-2009 oe:37P FROM:LIU AND ASSOCIATES 4254B62746 TO:14257753312 P.1/1 DAILY FIELD REPORT LIU & ASSOCIATES, INC. BA039 n meenng Geology dt �xATi Sctenna e5 Oeotechni nginernng, g $0 19213 Kenlake Place NE Kenmore, Washington 99029 Phone: (425) 483-9134 Fax- (425) 486-2746 J. Liu 1 1 of 1 2 At the request by Rudy with Universal Land Company, I come on site today to evaluate cut bank stabititrand f t footing bearing soils for the construction of the stormwater detention vault located near the northwest corner of the sub'ect ro'ect site. At the time of my site visit, the vaul�it has been cut down about 10 to 11 feet to at or within inches of the finish sub�de soils below the floor slab. The cut banks are sloped at about 1H:1for the top 5 to 5.5 -_ feet and are vertical for the bottom 4.5 to 5 feet. The cut banks encountered about 3 to 4 feet off fill and/or brown Weathered till of medium -dense silty fine send with a trace of gravel, underlain b a rater fresh till deposit of weekly-_ cemented, silty fine sand with some gravel and occasional cobble to bottom of the pit�A ditch is being cut along the base of the cut banks to intercept groundwater seep�e, but the�it has not encountered any groundwater seepage. The cut banks appear to be quite stable without any soil erosion or slow hing. A steel T-bar manual{y pushed into the footing bearing fresh till soils at bottom of the pit can penetrate no more than an inch or two, indicating the soils are very dense. -- _ Based on our observation and�bing of the bearing soils, it is our opinion that the cut banks of the vault i�i be able to remain stable for the duration of construction for the detention vault, and that it will safe for construction work to access or work in the vault pit. Army loose disturbed soils within footing trenches of the vault should be thoroughly removed down to undisturbed native fresh till soils. If this is accom lished, it is m opinion that the footin bearing soils will be able to render an allowable bearin capac' of at least 6,000 sf. COIN 1o: ❑ Continued 1) Terry Murphy/Murphy Building Co. 2) Rudy/Universal Land Co. on Next DAILY FIELD REPORT LIU & ASSOCIATES, INC. Job o. 8A039 Field Kep. J. Liu Page 1 of 1 Keport No. 1 Gcotechnrcal Engineering, Enginecring Geology & Earth Science Miles 30 Time On Site 9:05A Date 1/21/2009 Day of Week Wed. 19213 Kenlake Place NE Kenmore, Washington 98028 Phone: (425) 483-9134 Fax: (425) 486-2746 rave ime ( rsTime 0.75 Off Site 9:35A Weather Fo /Cloud Vehicle Hr-s-c-n-i—te Hrs Charged 1.25 v1snocs r'o!ect Willowdale Townhomes Jo Location 20628 - 76th Avenue W, Edmonds Client Murphy Building Co. General Contractor Murphy Building Co. General Contractor Project Manager Terry Murphy Received Unchecked By Eantwm* Contractor Universal Land Construction Co. 1 Piling Contractor Supt. Rudy Received Checked By At the request by Rudy with Universal Land Company, I come on site today to observe condition of the exposed soils in the pit created by demolition and removal of the building with a basement which used to occupy about the eastern one-third of the site The pit is about 80 feetby 80 feet at the top and about 10 to 12 feet deep with about 1 H: i V to 1-1/2HAV cut banks around from top to bottom of the pit. The bottom of the pit is excavated into a gravelly, silty, fine to coarse sand deposit Groundwater is not encountered by the pit A steel T-bar manually pushed into the bottom of the pit can penetrate no more than 3 to 4 Inches, indicating the soils at bottom of the pit are dense to very dense. A stockpile of crushed concrete, brick and asphalt fragments, from demolished building onsite, intermixed with soils, is stored at the southwest corner of the site. The material of this stockpile, to be used to backfill the excavated pit, is relatively clean, but contains minor amount of crushed parficles larger 4 inches and roots and branches. To be used as backfill of the pit, the particles larger than 4 inches and the organic material in the stockpile should be removed as much as possible. The exposed soils at the bottom and cut banks of the pit should be compacted thoroughly to a non -yielding state with a vibratory mechanical compactor and/or a hoe -pack before placing the first lift of backfill. The backfill should be pkamd in lifts no more than 10 inches in loose state, with each lift compacted with a vibnatory compactor to a non -yielding state and required density. Backfill along edges and at comers should be thorough!thorough!y compacted. It is important that backfill of the pit should be properly compacted in order to prevent settlement and structural damage to buildings and mwdway pavement to be constructed over the backfill. Since there are soils intermixed with the crushed concrete, brick and asphalt particles, it is my opinion that the filter fabric liner oqq1nally recommended to cover the top of the backfill may be eliminated. The top of the backfill should still be covered with a minimum 18 inch layer of mrn acted impervious soils to seal off the backfill and "his sealer layer should be extended at least 2 feet beyond edges of the backfill. 4-1 WAS COP - — - I 1, .irtea 7 c rn o: 1) Terry Murphy/Murphy Building Co. 2) Rudy/Universal Land Co. 3) 4) ❑ Continued on Next Page DAILY FIELD REPORT LIU & ASSOCIATES, INC. Job No. 8A039 is Rep. J. Liu age 1 of 1 a o. 2 Geotechnical Engineering, Engineering Geology & Earth Science Miles 30 Time On Site 2:45P Date 2/2/2009 Day of Week Mon_ 19213 Kenlake Place NE Kenmore, Washington 98028 Phone: (425) 483-9134 Fax: (425) 486-2746 Travel Time (Hrs) 0.75 Time Off Site 3:15P Bather Sunny Vehicle His on Site Hrs Changed 125 Visitors Project Willowdale Townhomes Job I tion 20628 - 76th Avenue W, Edmonds Glient Murphy BuildingCo. tract General Contractor Murphy Building Co. General Contractor Project Manager Terry.Murphy Received Unchecked By Earthwork Contractor Universal Land Construction Co. Piling Contractor Supt. Rudy Received Checked By At the request by Rudy with Universal Land Company, I come on site today to evaluate cut bank stability and verify footing beadnq soils for the construction of the stormwater detention vault located near the northwest corner of the subject project site. At the time of my site visit, the vat,lt pit has been cut down about 10 t:, 11 feet to at or within inches of the finish Subgrade soils below the floor slab. The cut banks are sloped at about 1HAVforthetop 5 to 5.5 feet and are vertical for the bottom 4.5 to 5 feet. The cut banks encountered about 3 to 4 feet of fill and/or brown weathered till of medium -dense silty fine sand with a trace of gravel, underlain by a gray fresh till deposit of weak - cemented, silty fine sand with some gravel and occasional cobble to bottom of the pit A ditch is being cut along the base of the cut banks to intercept groundwater seepage, but the pit has not encountered any groundwater seepage. The cut banks appear to be quite stable without any soil erosion or sloughing. A steel T-bar manually pushed into the footing bearing fresh till soils at bottom of the pit can penetrate no more than an inch or two, indicating the soils are very dense. Based on our observation and probing of the bearing soils, it is our opinion that the cut banks of the vault pit will be able to remain stable for the duration of construction for the detention vault, and that it will safe for construction workers to access or work in the vault pft. Any loose disturbed soils within footing trenches of the vault should be thoroughly removed down to undisturbed native fresh till soils. If this is a=m lished, it is my opinion that the footing bearing soils will be able to render an allowable bearing capacity of at least 6,000 psf. APP-11 OF WAS ! .c• --- a . TONAL ' l.ronv to. 1) Terry Murphy/Murphy Building Co. 2) Rudy/Universal Land Co. 3 4) ❑ Continued on Next Page FE9-10-2009 09:27A FROM:LIU AND ASSOCIATES 4254862746 TO:14257753312 P.1/1 DAILY FIELD REPORT Job No. Field Rep. wage Report No. LIU & ASSOCIATES, INC. 8AO39 J. Liu 1 of 1 3 Gcotcchnicnt Engmccring, Engineering Geology et � Scrcncc es 30 me n le 12:45P ate 2/9/2009 ay o ee Mon. — 19213 Kenlake Place NE Travel Time rsTime Off Site ea er Kenmore, Washington 98028 1 0.75 1115P Partly Cloudy Phone: (425) 493-9134 Fax: (425) 486-2746 Venicle Hirs on Site Hrs Charged Visitors 1.25 rolec o oca ion ien Willowdale Townhomes 20828 - 76th Avenue W. Edmonds Murphy Building Co. General Contractor General Contractor Project Manager Received Unchecked By Murphy Building Co. Terry Mur h Earthwork Contractor Piling Contractor Supt. Received Checked By Universal Land Construction Co. -Rudy At the request by Rudy with Universal Land Company, I come on site today to evaluate cut bank stability and verify footing bearing soils for the construction of the stormwater detention vault located at the east end of the sub'ect project site. At the time of my site visit, the vault pit has already been cut down about 11 to 12 feet to the finish subgrade soils below the floor slab and footing foundations. The cut banks are sloped at about 1H:1V for the top 4 to 7 feet and are vertical for the bottom 4.5 to 6 feet. The cut banks inn the northern half of the vault pit encountered about 3 to 4 feet of brown weathered till of medium -dense silty fine sand with a trace of gravel underlain by a ray fresh till deposit of weakly -cemented, silty fine sand with some gravel and occasional cobble to bottom of the pit, while the southern half of the vault pit encountered structural fill of silty fine sand with gravel and occasional cobble to _ the bottom of the pit. A ditch is being cut along the base of the cut banks to intercept groundwater seepage, but the pit has not encountered any groundwater seepage. The cut banks appear to be quite stable without any soil erosion or sloughing. A steel T-bar manually pushed into the _ footing bearing soils at bottom of the pit can penetrate no more than an inch into the fresh till deposit and about 1.5 to 3 inches into the structural fill, indicating the fresh till soils are very dense and the structural fill dense. Based on our observation andprobing of the bearing soils, it is our opinion that the cut banks of the vault pLit will be able to remain stable for the duration of construction for the detention vault, and that it will safe for construction workers to access or work in the vault pit. Any loose disturbed soils within footing trenches of the vault should be thorough* removed down to undisturbed native fresh till soils. If this is accomplished, it is my opinion that the fooflno bearing soils will be able to render an allowable bearing capacity of at least 4,000 psf. - - - — - - --- ---- -- ---- - - W H c' - - l 27589 bc- ODV to: p Continued 1) Terry Murphy/Murphy Building Co. 2) Rudy/Universal Land Co. on Next 3 4) Page