1400 W MARINE VIEW DR WATERFRONT PLACE APARTMENTS Geotech Report 2022-10-25

• ■ 2 inches of differential seismic settlement over a horizontal distance of 50 feet • Less than 2 inches of lateral spreading s Allowable bearing pressure of 4,000 pounds per square foot(psf) The contractor shall provide sufficient documentation and/or analysis to support the mitigation for lateral spreading for the geotechnical engineer to review. Design Constraints We understand that the Port of Everett is in the process of installing civil improvements adjacent to the project site, as discussed previously. Due to the proximity of the new civil improvements,the lateral extent of the ground improvement should be constrained to within the property line to minimize impact to civil improvements. In addition, the ground improvement program should consider means and methods that will result in no adverse impacts to existing/planned civil improvements. Preconstruction Survey A monitoring program should be established to provide early detection of deflections that could potentially damage nearby improvements. Additionally, we recommend that a preconstruction survey of adjacent improvements, such as streets, utilities and buildings, be performed prior to commencing ground improvement construction. The preconstruction survey should include a video or photographic survey of the condition of existing improvements to establish the preconstruction condition, with special attention to existing cracks in streets or buildings. • Optical Survey An optical survey monitoring program should be established to evaluate whether ground improvement construction is resulting in deformations in nearby existing improvements.The recommended frequency of monitoring should vary as a function of the stage of construction as presented in the following table. TABLE 2. CONSTRUCTION MONITORING FREQUENCY Construction Stage Monitoring Frequency During ground improvement construction Twice weekly During ground improvement construction if deformations exceed 1 inch and until deformations have stabilized Three times per week Monitoring should include vertical and horizontal survey measurements accurate to at least 0.01 feet. A baseline reading of the monitoring points should be completed prior to beginning of ground improvement installation.The survey data should be provided to GeoEngineers for review within 24 hours. We recommend that optical survey points be established on existing buildings located within a horizontal distance of 60 feet of planned ground improvement installation.The survey points located on the existing buildings should be located at an approximate spacing of 25 feet. i GEOENGINEERs May31,2017 Page 7 File No.22360-003-00