2701 ROCKEFELLER AVE NIMBUS Geotech Report 2023-12-29

OpportenlNZone Devebpment LLC JN 19152 June e, 2019 Page I I surrounding on -grade elements, such as foundations and slabs. Therefore, we recommend making an extensive photographic and visual survey of the project vicinity, prior to demolition activities, installing shoring or commencing excavation. This documents the condition of buildings, pavements, and utilities in the Immediate vicinity of the site In order to avoid, and protect the owner from, unsubstantiated damage claims by surrounding property owners. Additionally, the shoring walls and any adjacent foundations should be monitored during construction to dialect soil movements. To monitor their performance, we recommend establishing a sodas of survey reference points to measure any horizontal deflections of the shoring system. Control points should be established at a distance well away from the walls and slopes, and deflections from the reference points should be measured throughout construction by survey methods. At least every other soldier pile should be monitored by taking readings at the top of the pile. Additionally, benchmarks Installed on the surrounding buildings should be monitored for at least vertical movement. We suggest taking the readings at least once a week, until it is established that no deflections are occurring. The Initial readings for this monitoring should be taken before starting any demolition or excavation on the site. FOUNDATIONAND RETAINING WALLS Retaining walls should be designed to resist the lateral earth pressures imposed by the soil they retain. The follovnng recommended parameters are far walls that restrain level backfill: Active Earth Pressure a Backfilled Retaining Wells - Yielding Wells 35 pcf • Restrained Wells 23H Pod Foundation Walls Constructed Against Temporary Shoring Walls - Yielding Wells 30 pcf - Restrained Wells 20H pcf Passive Each Pressure 350 pcf Ocefficlant of Friction 0.50 Soil Unit W elghl 135 pcf Where: pal to Pounds per Cubic Fool, and Actions and Passive Earth Pressures ere computed using the Equivalent Fluid Preeaures. It For a restrained well that cannot defect M least 0.002 times IN height, a unllorld 191Mtl pressure Mould M used for the design we shown above. H Is the effective design Might of the well. This Nxiles only to world with Taal pool The design values given above do not include the effects of any hydrostatic pressures behind the walla and assume that no surcharges, such as those caused by slopes, vehicles, or adjacent foundations will be exerted on the walls. If these conditions exist, those pressures should be added to the above lateral soil pressures. Where sloping backfill is desired behind the walls, we will need to be given the wall dimensions and the slope of the backfill In order to provide the appropriate design earth pressures. The surcharge due to traffic loads behind a wall can typically be accounted for by adding a uniform pressure equal to 2 feet multiplied by the above active fluid density. Heavy CEOTECH CONSULTANTS, INC.