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GEOTECHNICAL SUPERVISION & INSPECTION SER CETtgVI ERETT STEEL COMPANY <br />PROJECT/FEBRUARY 2, 1991 THROUGH FEBRUARY 11, <br />3/0r - /fit` (_4-06 - <br />2s � 76 <br />A. HWA inspectors performed reinforced concrete inspection of ten column footings and piers on <br />February 5 & 6, 1991. Rested was corrected as per HWA instructions (see inspection daily <br />reports made on February 5, 199; ). <br />B. Subcontractor started the excavation operation of remaining footings on line A between lines 2 & <br />16 on February 7, 1991. Encountered growl water seepage at approximately 3 feet below the <br />existing ground surface elevation a: footing A-16. HWA engineer instructed the KCC to start <br />pumping the water out of the excavated hole. KCC performed pumping and excavation opera- <br />tion periodically. First pump went out of order. Second pump was not big enough to keep up <br />with the water flow rate. Stiff to hard, bearing soil was encountered at 9 feet depth elevation. <br />KCC started the excavation of the footing at A-15. The same conditions were observed, <br />however the native soil was not observed at the bottom of the excavated hole, 9 feet depth. <br />Also one concrete footing and a slab were encountered during the excavation (see red dotted <br />lines on the attached pictures). HWA instructed the owners representative and KCC to: <br />1. Provide one more pump and continue the pumping operation. <br />2. Demolish the old, existing concrete footing and slab. <br />3. Provide excavation box equal or greater than the footing dimensions, or provide a bigger <br />backhoe wiht clean up plates, in order to be able to excavate the hole faster and fill it up with <br />concrete mix right away. <br />4. Dig down to the firm native soil and take out all the loose soil inside the box footprint. <br />5. Place the control density fill inside the box right after the excavation, while pumping the <br />water out of the hole. <br />6. Stop pumping the water. Pull out the box gradually and fill up the hole with more control <br />density till. <br />C. HWA continued monitoring the excavation of footings A-15 & A-16, on February 8, 1991. Water <br />was pumped out, old concrete was demolished, and a MDI YOTANI, model 149B backhoe <br />was operated by KCC. Excavated down to the firm native soil and filled up the hole with con- <br />trol density till (See attached pictures and excavation records). The concrete for the remainder <br />of the column footings (on line B), was placed and inspected on this date. <br />D. Soils bearing was verified for footings A-14 Through A-2, by HWA representative, on February <br />It, 1991. <br />-BONG Wtsr err Asst)c:1 ,r�-zi <br />