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HomeMy WebLinkAboutOC_RS041332 - SoilsF_. { _1 I SCOTT AND PAULA BOWERS April 27, 2004 J.N. 185-04 Page 38 However, as a minimum, the masonry block wall footings should be embedded at least 18 inches below the adj acent final grade. In addition, it is recommended that the block wall footings be reinforced with a minimum of four No. 4 bars, two top and two bottom. In order to minimize the potential for unsightly cracking related to the possible effects of differential settlement, positive separations (construction joints) should also be provided in the block walls at each corner and at horizontal intervals of approximately 20 to 25 feet. The separations should be provided in the blocks and not extend through the footings. The footings should be poured monolithically with continuous rebars to serve as effective "grade beams" below the walls. Construction Near the Ton of the Rear Yard Descending Slope As described previously, a slope creep condition developing to a depth of approximately 5 feet deep can be anticipated for the rear yard slopes. On the basis of this anticipated condition, the block walls proposed near the tops of the descending slopes should be supported on either deepened footings or shallow caissons in order to mitigate the potential adverse effects of slope creep. Recommendations for deepened footings and caissons are provided below: 1. Deepened Footings: Footings for the block wall proposed along the top of the rear yard descending slopes should be founded at a depth that will provide a minimum footing setback of at least 15 feet measured along a horizontal line projected from the outside bottom edges of the footings to the daylight contact with the slope face in order to extend the footings below the creep zone. It should be noted that additional footing depths may be required to resist the potential creep forces and to achieve the necessary passive resistance against lateral movement as determined by the project structural engineer based on the soil parameters provided below. Footings for block walls at the above recommended minimum setbacks may be designed using the allowable bearing values recommended previously for building footings founded in compacted fill; however, when calculating passive