This project evaluated the force-displacement response of buried pipelines under saturated sand and clay conditions under lateral loading. This research was full scale. A review of accepted methods of offshore pipeline/soil interaction analysis, especially pertaining to mudslides and earthquake-related hazards was conducted.
This is a Joint Industry Project (JIP). The project evaluated guidelines for offshore platform topsides in seismic areas and review technical issues, such as the calculation of deck acceleration and the application of offshore seismic experience to offshore facilities. The project had two phases to develop guidelines then test on actual platforms and refine before implementation. The first phase developed the evaluation methodology, screening evaluation criteria, and methods of documentation.
A probabilistic seismic hazard analysis (PSHA) will be conducted to assess the levels of vibratory ground motions expected during various time periods. The results will be used to update current seismic hazard maps that have been used in the Santa Barbara Channel area since the 1960's, in the review of seismic design criteria and seismic performance of offshore structures. This is a 2 year, 3 phase project. The first phase of the study will collect data from the USGS, MMS, relevant experts, and oil companies to identify all available seismic design criteria for offshore platforms.
In Arctic regions, ice scour imposes a potential danger to seabed facilities such as pipelines. The purpose is to define the subscour forces and displacements, and thus, create a soundly based design methodology. This work is an outgrowth of the Pressure Ridge Ice Scour Experiment (PRISE). This effort is an adjunct study to Project No. 191.
This is a Joint Industry Project (JIP). The purpose was to develop a set of attenuation equations that could be used to confidently estimate the ground motions in offshore basinal environments that are generated by crust earthquakes. Attenuation equations for computing earthquake ground motions are a key input in deterministic and probabilistic seismic hazard analysis.
Develop a method for examining the adequacy of planned casing programs for minimizing platform vulnerability to cratering. Some operators use a rule of thumb that a well can be safely shut-in when casing is set at a certain depth. However, that depth is highly variable. This area of well design is currently poorly understood. The information generated by this project will be useful to identify and resolve technological and procedural barriers related to well control for deepwater development in the Gulf of Mexico and California regions as well as arctic drilling in Alaska.
This was a Joint Industry Project (JIP) and is an adjunct to Project No. 128. The study consisted of scaled laboratory tests of model piles loaded in biased tension during simulated earthquakes under two conditions that an earlier study suggested may be critical for the design of such piles. Piles used for foundations such as those for tension-leg platforms and pile-supported hydraulic structures. These conditions, were addressed in two separate tasks, including:
The workshop explored the current state-of- the-knowledge concerning the effects of pile driving on adjacent soil properties and determined areas where more research may be required. It is recognized that the properties of soils are sometimes changed by the installation of piles and that time- dependent effects are often part of these changes. The workshop sought to develop avenues of research to lead to the prediction of soil modification by pile driving so that altered properties can be considered in design of pile foundations.
The objective was to analyze existing and future recordings from the Seafloor Earthquake Measurement System (SEMS), and to perform theoretical calculations to improve our understanding of seafloor motions from earthquakes.
The objective was to develop a systematic seismic hazard approach for the requalification of existing platforms. The need for quantified assessment of the safety implications of inspections and repairs has led to incorporating such information into the decision process. No definitive engineering guidelines have been developed for defining a program for platforms located in seismically active areas. The research resulted in development of a practicable methodology for the safety management of fixed platforms in areas subject to earthquakes.
