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HomeMy WebLinkAbout12-22-1988 Soil Test Report Pg2 of 3662 CROMWELL AVENUE ST. PAUL. MN 55114 PHONE 612/645-3601 SQlUBSERVAnCN$.aiILlESTlll5 LABORATORY No. 4220 89>464 December 22* 1968 2 one»ha1f stcries above the existing grade. The addition xill be 19* wide by 24' long with a floor slab elevation matching the existing slab elevation of the lower floor of the existing house. The addition will be supported on e perin«ter strip footing approximately 2* in width. We have not been provided with the soil bearing pressures from the proposed project* but we assume they will be on the order of 150C to 2000 psf. Tc our knowledge* no deep soil test borings were performed for this project. Accordingly* we cannot comment on the soil conditions beneath the depths of our shallow hand auger borings. CBSEWATION ICTWODS AMD RESULTS On November 10* 1988* we visited the site at the contractors request to review the soils exposed in the perimeter footing trench excavations. Our observation methods included observing the sides of the excavation* placing shallow hand auger borings within the exposed excavation bottoms and classifying the retrieved soils according to ASTN:D2488. In addition* estimates were made of the strength properties of the retrieved soils. In the majority of the footing excavations* the surficial topsoil and any soft fill soils appeared to have been adequately removed. The soils exposed at planned bottom of footing elevation typically consisted of stiff sandy lean clay* or medium dense clayey sand and silty sand. We also observed that the perimeter footing excavaticr. matched the bottom of the existing building at the southeast addition corner and was approximately 2' below the existing footing elevation at the southwest building corner. The soils observed in the excavations appeared to be naturally occurring glacial till* and were judged suitable for support of assumed loadings of 1500 to 2000 psf. The exception to the above noted soil conditions occurred at two locations. A1 a point approximately 8* west of the southeast corner of the addition* the footing line intersected the existing sanitary sewer pipe for the residence. We recommended that approximately 2' of additional excavation be performed in this area to allow the new footing to step under the existing sewer pipe. Based on our hand auger borings* it appeared that soils exposed at the bottom of this additional 2* cut would be suitable naturally cccurring soils similar to the majority of the footing areas. At a point near •liie southwest corner of the proposed addition area* the footing trench again intersected the fill soils from an existing utility line in this area. This previous trench appeared to be approximately 1' wide and 2' to 3* deep. In this area* the contractor elected to construct a small grade beam to span over the existing utility trench fill soils and allow the footing loads in this area to be carried by the more competent natural soils encountered on either side of the trench. It appeared that the natural soils on either side of the trench would be suitable for support of the additicnal loads transmitted from the grade beam to the foundation elements. CATWMf enow TOC ILVM»AU*C Anew OP or ATOMOWTO* c ITMA CONI POOTOlOP ATVOPeUPNTO.