2701 ROCKEFELLER AVE NIMBUS Geotech Report 2023-12-29

Opportunity Zone Oewdopment LLC JN 19152 June 6, 201e Page 6 foundation. For the latter condition, the foundation must be either poured directly against relatively level, undisturbed soil or be surrounded by level, well -compacted fill. We recommend using the following ultimate values for the foundation's resistance to lateral loading: Coefficient of Friction 0.50 Passive Earth Pressure 350 pot whose: pd Is Pounds per Cubic Foot, and Passive Earth Pressure Is computed using the Equivalent Fluid Density. If the ground in front of a foundation Is loose or sloping, the passive earth pressure given above will not be appropriate. The above ultimate values for passive earth pressure and coefficient of friction do not include a safety factor. SHORING This section presents design considerations for cantilevered or tied -back soldier pile walls, and for soil nailed walls. Since the most suitable choice is primarily dependent on a number of factors under the contractor's control, we suggest that the contractor work closely with the structural engineer during the shoring design. The choice of appropriate soldler pile Installation methods should be the responsibility of the shoring engineer and contractor, who should be provided with the results of the subsurface explorations. Installation techniques often must be modified to address conditions that are encountered In the actual construction process. This may be necessary once the excavation extends through the glacial till into the clean outwash sand below depths of 15 to 27 feet below grade. This can also occur when boulders or other obstructions are encountered within the glacially -compressed soils. We recommend that you request information from the contractor regarding potential additional costs should shoring techniques need to be changed for site conditions. The sensitivity of adjacent buildings, streets, and utilities must be considered In the design to reduce the risk of causing settlement of these adjacent elements. Regardless of the system used, all shoring systems will deflect in towards the excavation. Therefore, there is always a risk of noticeable settlement occurring on the ground behind the shoring wall. These risks are reduced, but not entirely eliminated by, using more rigid shoring systems such as soldier piles and tie -back anchors. The General section should also be reviewed for additional shoring considerations. The shoring design should be submitted to Geotech Consultants, Inc. for review prior to beginning site excavation. We are available and would be pleased to assist In this design effort. Safety factors of 1.2 and 1.5 should be used for temporary and permanent shoring designs respectively. Also, If the shoring Is considered permanent, the seismic surcharge provided in the Foundation and Retaining Wall section needs to be included. Cantilevered and Tled-Beck Soldier Piles Cantilevered and tied -back soldier pile systems have proven to be an efficient and economical method for providing excavation shoring. Tied -back walls are typically more OEOTECH CCNS6LTp S, INC.