625 S Cypress Ave - Plan - Laserfiche WebLink

Home Browse Search

625 Cypress Avenue Geotechnical Investigation Project No. W1895-88-01 - 21 - April 23, 2024 7.5.7 The project structural engineer should evaluate the existing foundations, existing loads, and proposed building loads. Where excess capacity remains, the existing foundations may be utilized for support of the proposed improvements. However, adding heavier loads to existing foundations could induce settlements on the existing foundations which could be detrimental to existing structural connections. Once existing and proposed load configurations become available, they should be provided to Geocon for additional settlement analyses. The structural engineer should evaluate the anticipated load configuration and resulting settlements, and determine the necessity for new foundations. Recommendations for new foundations are provided in the following section. The project structural engineer should verify the suitability and reinforcement design for all existing and new footings. 7.6 New Foundation Design 7.6.1 Where new footings are required for support of the proposed improvements, conventional foundations may be used. Foundations should derive support in the undisturbed alluvial soils found at and below a depth of 5 feet. Foundations should be deepened as necessary to penetrate through any unsuitable soils and derive support exclusively in the undisturbed alluvial soils. The presence of existing artificial fill in proposed foundation excavations must be field verified by Geocon during construction activities. 7.6.2 Proposed foundations that are situated immediately adjacent to the existing foundations should be deepened as necessary to match the depth of the existing foundation to prevent a surcharge on the existing foundation. 7.6.3 Where proposed foundations will be deeper than the existing foundation, the proposed foundation must be designed to resist the surcharge imposed by the existing foundation. The surcharge area may be defined by a 1:1 projection up and away from the bottom of an existing foundation. 7.6.4 The enclosed seismically induced settlement analyses indicate that the site soils could be susceptible up to approximately ½ inch of total settlement as a result of the Design Earthquake peak ground acceleration (⅔PGAM). The resulting differential settlement is anticipated to be less than ¼ inch over a distance of 30 feet. These settlements are in addition to the static settlements indicated and must be considered in the structural design. 7.6.5 In order to minimize settlements to less than ½ inch between existing and proposed foundations, a reduced bearing capacity is being recommended. Continuous and isolated