Appeal 33496

ASCE 7-16 15.4.10.1 Nonbuiding Structures on Shallow Foundations and 12.13.9 Requirements for Foundations on Liquefiable Sites

ASCE 7-16 15.4.10.1 - Nonbuilding structures shall not be permitted to be supported on shallow foundations at lique?able sites unless it can be demonstrated that the structure’s foundation, superstructure, and connecting systems can be designed to accommodate the soil strength loss, lateral spreading, and total and differential settlements induced by MCEG earthquake ground motions indicated in the geotechnical investigation report.

ASCE 7-16 12.13.9 - Where the geotechnical investigation report required in Section 11.8 identi?es the potential for soil strength loss caused by liquefaction in MCEG earthquake motions, structures shall be designed to accommodate the effects of liquefaction in accordance with the requirements of Sections 12.13.9.1 through 12.13.9.3. Such structures shall also be designed to resist the seismic load effects of Section 12.4, presuming liquefaction does not occur.

This request is to appeal the enforcement of 2022 OSSC SECTION 1613 in it's reference to ASCE 7-16 in Section 1613.1. Specifically, the sections in Ch. 15 and 12 mentioned above regarding deep foundations and lateral spreading mitigation. Note that all other requirements for seismic design will be met.

Based on mitigating circumstances provided by existing product control procedures and attributes of the existing site structures and support soils, the proposed design provides for a reasonable degree of safety under liquefaction conditions. See the attached memo and below for a more detailed description.

The existing flow control measures are as follows: As required by Coast Guard regulations, 33 CFR 154, all transfer operations are manned. During transfer operations, in the event of an emergency, the operator in charge can stop the flow of hazardous materials by an electrical, pneumatic, or mechanical linkage or an electronic voice communications system continuously operated by a person on the facility who can stop the flow of hazardous material immediately. For hazardous materials transfers at docks operated prior to October 4, 1990, this is within 60 seconds. The current design and operations of the facility provides meets or exceeds these requirements. Each new vapor line will have a valve located at the skid and at the dock approach trestle. When the vapor lines are not in use, these valves are closed. The requirements of ASCE 7-16, 12.13.9 have not been considered and the design assumes the piping system will fail under conditions where the soil experiences liquefaction. This note will be included on the plans as part of the plan review resubmittal. As noted above, documentation and calculations submitted for permit demonstrate that the proposed design will meet all other appropriate seismic requirements of the 2022 OSSC.

The primary purpose of this project is to enhance the environmental safety at the site by providing a Marine Vapor Combustion Unit, and installing new piping and sprinklers to the existing fire suppression system. By installing the MVCU the Owner will have the ability to further control regulated air emissions from marine operations. Additionally, upgrades to the fire system will improve operations, maintenance, and life safety. The scope of the project is very limited and mitigation for liquefaction, lateral spread, and flow failure using the typical tools of deep foundations and/or ground improvement is not practically scalable to this project.