Significant Impact Being Mitigated
Mitigation Measure
Responsibility for Implementation
Enforcement Responsibility
Monitoring Responsibility/ Frequency
Actions Indicating Compliance
Noise and Vibration (cont.)
Exposure of onsite historic structures to vibration from pile driving operations.
DSP, DSP-V, CPP, &
CPP-V scenarios
4.J-2b: Pre-Construction Assessment to Minimize Structural Pile-Driving Vibration Impacts on Adjacent Historic Buildings and Structures and Vibration Monitoring. Any development within 85 feet of the Roundhouse and the Machinery & Equipment Building that would require pile driving or other construction techniques that could result in vibrations of 0.25 in/sec shall engage a qualified geotechnical engineer subject to City approval to conduct a pre-construction assessment of existing subsurface conditions and the structural integrity of the nearby historic structures subject to pile- driving or other vibration-inducing activity before a building permit is issued to demonstrate that the proposed construction activities would not result in vibration-induced damage to the Roundhouse or the Machinery & Equipment building.
If recommended by the pre-construction assessment, groundborne vibration monitoring of nearby historic structures shall be required. Such methods and technologies shall be based on the specific conditions at the construction site such as, but not limited to, the
pre-construction surveying of potentially affected historic structures and underpinning of foundations of potentially affected structures, as necessary. The pre-construction assessment shall include a monitoring program to detect ground settlement or lateral movement of structures in the vicinity of pile-driving activities. Monitoring shall be maintained while construction occurs within 85 feet of historic structures, and results shall be submitted to the City Engineer. In the event of unacceptable ground with the potential to cause structural damage movement (in excess of 0.25 in/sec PPV at historic structures), as determined by the City Engineer, all impact work shall cease until corrective measures (e.g., installation of vibration wave barriers) are implemented to reduce ground movement to below 0.25 inches PPV.
In addition, the following measure shall be implemented:
- Evaluate and implement feasible measures for reducing vibration, such as alternative pile driving methods (e.g., cast‐ in‐drilled‐hole piles versus driven
Applicant(s) for development requiring pile driving or other construction techniques that could result in vibrations of 0.25 in/sec or more within 85 feet of the Roundhouse or Machinery
& Equipment Building shall provide a pre-construction assessment of existing subsurface conditions and report on the structural integrity of the nearby historic structures subject to pile-driving or other vibration-inducing activity prepared by a qualified geotechnical engineer approved by the City demonstrate that the proposed construction activities would not result in vibration-induced damage to the Roundhouse or the Machinery & Equipment building.
City of Brisbane Building Official
Prior to issuing any building permit(s) for development requiring pile driving or other construction techniques that could result in vibrations of 0.25 in/sec or more within 85 feet of the Roundhouse or Machinery
& Equipment Building, the City Building Official shall review the pre-construction assessment of existing subsurface conditions and report on the structural integrity of the nearby historic structures subject to pile-driving or other vibration-inducing activity prepared for the applicant by a qualified geotechnical engineer approved by the City to ensure that the proposed construction activities would not result in vibration-induced damage to the Roundhouse or the Machinery & Equipment building.
The City Building Official shall also be responsible for undertaking a pre- construction survey of the historic buildings to establish baseline against which any construction- related damage to the buildings can be measured. Minimum weekly inspections of the Roundhouse and Machinery & Equipment
Issuance of building permit(s) for pile driving or other construction techniques in compliance with Mitigation Measure 4.J- 2b.