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Matthew/ Aley Residence Summary Report of Monitoring of Subsurface Compaction and Chemical Grouting BCI Project No. 03-15564.1 June 2008 Page 3 NEC staked the grout injection point locations as shown on Figure 2 in accordance with BCl's recommendations. Vertical and angled grout points were installed using a 2-~ inch (inside diameter), steel casing. The grout casings were installed to competent hard limestone bedrock at depths ranging from 50 to 66 feet below existing grade. A total of 918 feet of grout casing was installed at 16 grout points. After the grout casings were installed, a high-pressure pump was used to inject a mixture of cement, fly ash, sand, water and other admixtures into the loose soils and voids in the limestone and overlying sand strata. Pumping continued until a grout pressure of 200 to 300 pounds per square inch (psi) was achieved (over that required to initiate grout take) or lifting of the structure was observed (via a surveyor's level). The grout casing was then extracted upward 2 to 3 feet and pumping resumed. The quantity of grout pumped into individual grout injection points ranged from 0.7 to 6.4 cubic yards for a total of33.3 cubic yards of grout used, as shown in Table 1. During the project, a BCI engineering technician was present to monitor the drilling and grouting operations and perform applicable grout tests. Compressive strength ofthe grout was tested by preparing 2-inch cube samples of grout. The cubes were cured in a controlled environment in our laboratory for seven days. After seven days, the cubes were tested in a compressive strength-testing machine. The test results indicated that the grout achieved the project requirement of 400 psi. Grout strength testing results are included in Appendix A. Slump tests were performed on selected samples during grouting operations and were within project specifications, with individual slumps ranging from 3 to S inches.