920 MILLWRIGHT LOOP S BASE FILE Geotech Report 2023-12-29

earthquake -induced lateral ground deformation, and etc., and prevent slope failure from occurring within the potential building footprints. 5.1. Rigid Inclusions Rigid inclusions are generally unreinforced, grouted or concrete columns installed in weak foundation soils to Improve the overall stiffness and strength so that the foundation soils can meet the settlement criteria and achieve the bearing capacity required for support of shallow Inundations of a structure. Rigid Inclusion elements are formed by constructing unrelnforced concrete columns using a continuous - flight, hollowstemauger attached to a set of leads supported by a crane or installed with a fixed -mast drill rig. The first step In the rigid Inclusion placement process consists of drilling the auger into the ground to the specified tip elevation of the rigid inclusion. Concrete is then pumped through the hollow -stem during steady withdrawal of the auger, replacing the sells on the flights of the auger. One benefit of using the sugarcoat method for rigid inclusion installation is that the auger provides support for the soils during the installation process, thus eliminating the need for temporary casing or drilling fluid. 5.2. Rigid Inclusions Design In this project, the rigid inclusions are designed to mitigate the ground deformations and the risk of slope failure within the potential building footprints due to earthquake by stiffening the liquefiable fill and recent deposits so that the foundation design of the buildings meets the performance criteria for bearing pressure, static and seismic settlements, and lateral spreading. The design bearing capacity of the improved foundation soils was estimated based on the axial capacity of each individual rigitl inclusion column and the load transfer between the columns and the surrounding soils. Design analyses were completed to estimate the total amount (i.e., number and depth) of the rigid inclusion columnsthat are required under the foundation; andtherefore,the static and seismic settlements meet the performance criteria. The post -improvement earthquake -induced lateral ground deformation was estimated by performing global slope stability and Newmark analyses that include the improved area with an increased composite strength. 5.2.L Rigid Inclusion Layout The rigid Inclusion design layout was developed for the building at Parcel A17 based on the foundation plan provided by PND on June 15, 2021. The rigid inclusion layout is summarized below. And the detail ground improvement plans, and construction specifications are Included In a separate design drawing submittal for Parcel A17. 2-faotdiameter rigid inclusions. iii Typical center-t"enter spacing is 6 feet 3 inches north -to -south and 5 fast 6 inches east -to -west in a square pattern below the building foundation. Refer to ground Improvement plan layout for additional details. iii Rigid inclusions should extend a minimum of 3 feet into the non liquefiable layer. The tip elevations are anticipated approximately at 44 feet. GEGENGINEEkS 67 D=Mr2020 osrPal