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JP Morgan Chase April 29, 2010 <br /> Geotechnicallnvestigation <br /> Proposed Chase Bank Everett, WA PSI Report No. J704186 <br /> of the borings was siity sand with some gravel. Boring B-4 indicated the presence of silty and <br /> sandy gravel at depihs rar�ging from approximately 2-1/2 feet to 7-1/2 feet bgs. Stan�ard <br /> Penetration Test (SPT) N-values in the silty sand and gravels ranged from 5 blows per foot to <br /> 50 blows in 6 inches (as noted on the Boring Logs) indicating loose to very dense materials. The <br /> average N-value was on the order of 25 blows per foot indicating generally medium dense <br /> material consistency ihroughout the explored site. <br /> Our interpretat:on of the soil e�countered at the site is shown in the Borings Logs provided in <br /> Appendix A. <br /> 3.2 GROUNDWATER <br /> Groundwater was encountered in three of the boringc:; e-1, B-2 and B-3. Groundwater was not <br /> encountered in Boring B-4. Approximate twenty-four hour (after drilling) groundwater depths <br /> were as follows: <br /> B-1: 12 feet bgs <br /> B-2: 7 feetbgs <br /> B-3 10 feetbgs <br /> Based on the information above, the average depth to groundwater is on the order of 9 to 10 <br /> feet bgs. Gro�ndwater is rot expected to cause problems during site construction. Generally, <br /> the highest groundwater levels occur in late winter and early spring (the time these borings were <br /> performed) and the lowest leveis in late summer and early fall. Therefore, water may be <br /> encountered duri��g construction at depths not indicated during this study. We recommend that <br /> the Contractor determine lhe actual yroundwater levels at the time of construction to determine <br /> pote�tial groundwater impact on the construction procedures. <br /> 4.0 CONCLUSIONS AND RECOMMENDATIONS <br /> 4.1 GENERAL <br /> Based on the results of our field explorations, laboratory testing results, and our engineering <br /> analysis, the site is s�itable for construction of the proposed improvements. Our specific <br /> recommendations for the project are provided below. <br /> 4.2 SITF. PREPARATION <br /> After demolition of the existing structure, the planned construction area should be stripped o( <br /> any remaining concrete slabs and footings, asphalt, utilities, vegetation, organic matter, and any <br /> deleterious 1ill, if encountered. Stripped material should be transported offsite (or disposal or <br /> stockpiled for later use as fill in landscaped areas, as approved by the site landscape architect. <br /> A member of our geotechnical staff should observe the exposed subgrade after strippinq, and <br /> N�' 3 <br />