Geotechnical Services Result in Huge Project Savings
Tighe & Bond provided comprehensive engineering services to PSNH for the design and construction of a new 45,000 square foot, 115-kV transmission substation adjacent to an existing substation. We relocated the access road to maintain continuous access to PSNH’s generation coal yard. A 10-foot grade difference between the two substations and the relocated access road required approximately 11,000 cubic yards of material removal and handling and the construction of an approximately 430-foot retaining wall.
Our scope of services included site design, local and state permitting services, wetland delineation services, preliminary and final geotechnical evaluations, soil pre-characterization, and soil management. Tighe & Bond conducted a combined geotechnically and environmental subsurface exploration program. After our environmental assessment and evaluation of soil management, we updated the substation’s footprint to minimize the volume of soil required to be managed offsite. These improvements resulted in a $500,000 project savings.
Geotechnical services included:
- Preliminary assessment of the subsurface conditions
- Determine the suitability of the site for the new substation
- Aid with new transmission equipment
- Reinforcement of structures
- Support of the retaining wall
- Recommendations for foundation
- Relocation of the access road
- Final evaluations
The project construction documents identified and incorporated the geotechnical implications of on-site design and construction.
Other Tighe & Bond services included the preparation of construction drawings and specifications, as well as a stormwater pollution prevention plan (SWPPP).