3214 BROADWAY SEPA 017 - 004 Geotech Report 2025-04-14

American Property Develo f..dent ES-0599.05 January 16, 2015 Page 10 Updated January 22, 2015 Shoring Monitoring Due to the close proximity of adjacent buildings and public right-of-ways, an optical monitoring program should be implemented for this site. The monitoring program should consist of a video or photo survey prior to beginning the building excavations to document the current conditions of the surrounding features. Initial survey points should be placed at strategic locations along adjacent foundations and right-of-way alignments that will allow for periodic measurement during and after the shoring installation. This will allow for efficient monitoring of the site to identify and remediate excessive deflections or excavation related movements, if they occur. Prior to the start of construction, the geotechnical engineer, owner, and contractor should review the project and develop a monitoring program for the site. Following installation of the soldier piles (if utilized), monitoring points are typically established on the top of the piles prior to proceeding with the excavation. An initial baseline reading should be acquired prior to proceeding with the excavation. Readings should be acquired relatively frequently during the excavation phase of the construction. The geotechnical engineer should review the data as it becomes available during the course of construction. The monitoring program should be supplemented with periodic observations by the geotechnical engineer during the excavation phase of construction. Foundations Based on the results of our study, the proposed assisted living facility can be supported on conventional spread and continuous footings bearing on competent, undisturbed native soil. Based on the planned excavations, we anticipate competent native soils suitable for support of foundations will be exposed at the foundation subgrade elevation. Where loose or unsuitable soils are exposed at the subgrade elevation, the soil should be overexcavated and replaced with a suitable crushed rock material. Crushed rock placed below foundations should consist of one and one half inch to two inch clean crushed rock. Assuming the foundations are supported on competent, undisturbed native soils or suitable crushed rock material, the following parameters should be used for foundation design: • Allowable Soil Bearing Capacity 10,000 psf • Friction 0.40 • Passive Resistance 350 pcf (equivalent fluid)* *Assumes foundations backfilled with structural fill For short term wind and seismic loading, a one-third increase in the allowable soil bearing capacity can be assumed. A factor-of-safety of 1.5 has been applied to the friction and passive resistance values. Earth Solutions NW,LLC