5131 DOGWOOD DR 2016-08-31 - Laserfiche WebLink

August 12, 2015 G-3945 Geotechnical Evaluation & Underpinning Engineering Page 4 5131 Dogwood Drive, Everett is installed in conformance with the manufactures instructions. The estimated post installation total and differential settlement is 0.5 inches. PIER SPACING Calculated Maximum Pier Spacing Estimates of the dead and live building foundation loads were calculated and the maximum allowable pier spacing was calculated using an allowable design capacity of 12,000 lbs per pier, attached. The following is the calculated maximum pier spacing for the east foundation wall: Calculated Max. Pier Spacing East Foundation Wall 6.78 feet Recommended Maximum Pier Spacing The height of the perimeter foundation wall was measured to be approximately 35 inches (27.5 inch stem wall plus a footing thickness of 7.5 inches). The shear capacity of the foundation was calculated and the following is the maximum recommended span of the sections of unsupported foundation between the pier brackets. Max. Span For Unsupported Foundation East Foundation Wall 5.5 feet If the pier spacing results in span that is greater than the maximum recommended unsupported span, we understand IFS can install spanning bar between the pier bracket and the bottom of the footing to reduce the length of the unsupported foundation section between the pier brackets. The spanning bar is made of 1/4 inch box steel and can be ordered in various cross sectional sizes (4"x4", 4"x6", 6"x6", etc.) and lengths. The actual pier spacing will depend on the length of the spanning bar installed, but the pier spacing should not exceed the calculated maximum pier spacing above. The pier bracket support plate under the footing measures 9.75 inches (0.81 feet) in width, so a pier spacing of 6.3 feet or less will result in an unsupported foundation span of 5.5 feet or less. GEO Group Northwest,Inc.