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Vibration Monitoring • <br /> Ground vibrations should be monitored at the beginning of ground improvement installation by <br /> GeoEngineers. The location of the vibration monitoring should be located near vibration sensitive <br /> improvements during ground improvement installation. The data collected from the instrument(s) will be <br /> monitored by GeoEngineers and the following actions will be initiated if peak particle velocities meet the <br /> vibration criteria limits presented below. <br /> 1. Stop ground improvement installation. <br /> 2. Complete visual monitoring of adjacent structures during ground improvement installation to evaluate <br /> if vibrations cause cosmetic damages of adjacent structures. <br /> TABLE 3.VIBRATION CRITERIA LIMITS <br /> Maximum Peak Particle Velocity <br /> Building/Improvement Category (inches/seconds) <br /> Buried utilities 1.5 <br /> Buildings 0.5 <br /> A record of the vibration monitoring data should be collected daily and incorporated into the geotechnical <br /> daily field reports. Vibration monitoring can be ceased after establishing a site specific minimum distance <br /> from ground improvement installation where 75 percent of the vibration criteria limits are not exceeded <br /> and confirmation that no existing improvements are located within this minimum distance for remaining <br /> ground improvement installation. • <br /> Construction Considerations <br /> Based on the explorations completed for this study and previous explorations by others,wood waste ranging <br /> from sawdust to timber/logs were encountered within the fill soils. The contractor should be prepared to <br /> encounter periodic wood waste and have a method in place to deal with this situation, such as predrilling <br /> where ground improvement elements are located or movingthe ground improvement points over 2 to 3 feet <br /> if an obstruction is encountered. Additionally, the surficial fill may contain foundation elements and/or <br /> utilities from previous site development, debris, rubble and/or cobbles and boulders. We recommend that <br /> procedures be identified in the project specifications for measurement and payment of work associated <br /> with obstructions. <br /> Shallow Foundations <br /> The proposed buildings may be supported on shallow foundations, provided that ground improvement is <br /> completed that meets the project design performance criteria. <br /> Allowable Bearing Pressure <br /> For foundations bearing directly on improved soils, an allowable bearing pressure of 4,000 psf can be <br /> assumed.The allowable soil bearing pressure applies to the total of dead and long-term live loads and may <br /> be increased by up to one-third for wind or seismic loads. The allowable soil bearing pressures are net <br /> values. <br /> 1111 <br /> GEOENGINEERS May 31,2017 Page 8 <br /> He No.22360.003-00 <br />