HDR Engineering Amend 2 - Laserfiche WebLink

EN 2. Evaluate Seismic Design Parameters: Based on the geologic information near the FEN improvements, HWA will determine the Site Class for seismic design. 3. Evaluate Liquefaction and Lateral Spreading: HWA will evaluate the susceptibility to liquefaction at the location of the proposed vault with the soil information obtained from the proposed additional boring. Once the susceptibility to liquefaction is determined, we will evaluate the potential for lateral spreading and other potential impacts to the proposed and existing structures. 4. Settlement Analysis: The chlorine building will be located on the north side of the dike and will require fill placement to achieve finish floor elevation. HWA will estimate settlements due to site grading at the locations of the proposed new chlorine building and the new vault. Also, HWA will evaluate possible consolidation settlements due to site grading. 5. Foundation Vertical Capacities: HWA will evaluate vertical foundation pile capacities and provide recommendations for pile design for the proposed new chlorine building, culvert and vault structures. 6. Pile Foundation Lateral Parameters: HWA will perform lateral analyses of pile foundations using LPILE. Per design team request, HWA will provide lateral soil resistance parameters in the form of spring constants for the piles at 2-foot intervals over the full depths of the piles. 7. Fill/Preload Recommendations on Proposed Chlorine Building: The chlorine building will be located at the north side of the dike and will require fill placement to achieve finish floor elevation. HWA will provide fill/preload recommendations at this location, considering potential for consolidation settlements. 8. Preload Monitoring: HWA will provide preload monitoring recommendations at the proposed location of the chlorine building. 9. Retaining Wall Recommendation: It is our understanding that a retaining wall will be required at the proposed location of the chlorine building to accommodate increases in grade. HWA will provide design recommendations for the proposed retaining wall. 10. Lateral Earth Pressures: HWA will provide lateral earth pressure recommendations for below grade structures. 11. Shoring Design: HWA will provide shoring design recommendation for the construction of the proposed new vault and for the installation of the proposed culvert. 12. Vibration Monitoring Recommendations for Outfall Pipe near Proposed New Vault: It is understood that an existing 48-year-old, 48-inch diameter outfall pipe is connected to one of the manholes that will be replace during the vault construction. HWA will provide temporary monitoring recommendations for the existing monitoring pipe. 13. Earthwork and Dewatering Recommendations: HWA will develop recommendations for earthwork and construction dewatering, as needed. 14. HWA QA/QC: HWA will have all design calculations and recommendations reviewed by a senior principal prior to distribution to the design team or the City. 15. Project Coordination Meetings: HWA will meet with the City and design team to present our findings and discuss alternatives. (3 meetings) 16. Draft Geotechnical Engineering Report: HWA's geotechnical engineering report will present the results of the geotechnical engineering investigation, including a description of subsurface conditions; a site plan showing exploration locations and other pertinent City of Everett—WPCF FEN Phase 2 3 Scope of Services