Geotechnical

United States Department of the Interior

Content:
Michael Else

Pagemasters:
OEMM Web Team

Geotechnical

Monitoring earthquakes offshore    Scientists prepare a seismic probe
for installation off the California
coast.

The TA&R Safety and Pollution Prevention Program has recently completed two major seismic efforts:

Seafloor Earthquake Measurement System (SEMS), Phase IV was performed by the Sandia National Laboratories to analyze seafloor earthquake motion data for seismic active areas of Southern California and the Arctic. The SEMS uses a tethered underwater cable to connect the seafloor probe to a seismograph on an offshore platform. The data collected will help the MMS verify and modify models of soil response to seismic activity. The data will also aid in the design and regulation of offshore structures in seismically active areas. A network of three probes was installed along the southern California coast. The MMS is in the process of transferring the instrumentation and data collection operations of the sensor array to the State of California. An additional product of this project is a probabilistic seismic hazard map of the entire offshore area of the State of California.

Probabilistic Seismic Hazard Analysis for Offshore Structures in the Santa Barbara Channel, Phase 1 & Phase 2 is funded jointly by the MMS and the California State Lands Commission. The work is being performed by the Lawrence Livermore National Laboratory (LLNL). The project results are used by the MMS to develop regulations covering the evaluation of applications to re-license existing oil platforms subject to potential seismic impacts in the Federal waters of the Santa Barbara Channel. The final project report characterizes local earthquake sources within the channel as well as the onshore areas of the Western Transverse Ranges. There is also a description of a ground motion model for the region and the preliminary hazard analysis at three selected sites. Further research by the LLNL will be sponsored by the California State Lands Commission. The LLNL will develop hazard maps of ground motion expected to exceed the structural design capacity for platforms in the entire Santa Barbara Channel.

Geotechnical Projects
018	Overpressured Marine Sediments
045	Field Study of the Dynamic Response of Single Piles and Pile Groups in Stiff Clay
046	Behavior of Piles and Pile Groups in Cohesionless Soils
047	Study of Method of Design of Piles in Clay Soils Under Repeated Lateral Loads
048	A Study of Structural and Geo-technical Aspects of Tension Leg Platforms
057	Static Lateral Load Tests on Instrumented Piles in Sand
059	Foundation Stability of Jack-up Platforms
062	Southern Bering Sea Production System Study
068	Seafloor Seismic Data Study
069	Reliability of Gravel Mat Foundations for Arctic Gravity Structures
073	Soil Flow on Pipelines
079	Offshore Pipeline Transportation Study for Lease Sale 87
082	Numerical Wave Force Simulation
090	Evaluation of Short, Large-Diameter Piles for Arctic Applications
093	Site-Response, Liquefaction and Soil-Pile Interaction Studies Involving the Centrifuge
111	Development of a Method to Evaluate the Tension Capacity of Drilled and Grouted Piles
122	Earthquake Response of a Platform by the System Identification Technique
125	Seismic Response Analysis of Offshore Pile Supported Structures
128	Response of Piles to Earthquake Ground Motions
164	Chukchi Sea Transportation Update Study
166	Seismic Response Characteristics for Topside Facilities
171	International Workshop on the Seismic Design and Requalification of Offshore Platforms
172	Methodology for Assessing the Structural Integrity of Existing Platforms Subject to Seismic Loading
174	Assessment of Seafloor Earthquake Ground Motions
184	International Workshop on Pile Foundation
187	Analytical Simulation of Biased Loaded Tension Piles in Earthquakes
195	Shallow Gas Broaching
214	Ground Motion Attenuation Equations for Basin Environments.
219	Application of an Engineering Model for Ice/Soil/Pipeline Interaction
222	Probabilistic Seismic Hazard Analysis for Offshore Platforms in the Santa Barbara Channel
225	Development of Evaluation Guidelines for Offshore Platform Topsides in Seismic Regions
313	Large-scale modeling of pipeline soil interaction under lateral & axial loading
314	Continued Development of Earthquake Load and Resistance Factor Design Guidelines
327	Applied Gas Hydrate Research Program
340	Project Cancelled
341	Develop and Improved Methodology for Pre-drill Pore Pressure and Fracture Gradient Prediction
342	Project Cancelled
367	Soil Map of Shear Strength for Shallow Sediments in GOM
381	Identification And Characterization Of Shallow Water Flows Using Seismic Analysis Techniques
404	Project Offshore Deep Slopes (PODS): Seafloor Stability on the Continental Shelf/Slope (17177)
410	Deepwater Geohazards Workshop
421	Seafloor Slope Stability Assessment
422	Earthquake Assessment of Subsea Facilities/GOM
432	Regional Synthesis of the Sedimentary Thermal History and Hydrocarbon Maturation in the Deepwater Gulf of Mexico
445	Workshop on Slope Stability by C-Core consultants
461	Characterizing Natural Gas Hydrates in the Deepwater Gulf of Mexico
479	Deep-Sea Furrows
484	Oceanic Turbulence Project (Ocean Turbulence Loads and Effects on Offshore Structures)
491	Risk Assessment for Submarine Slope Stability
557	Numerical Modeling of Torpedo Anchors
608	Methods to Reduce Lateral Noise Propagation from Seismic Exploration Vessels
619	Subject An Interactive Met-Ocean Geographical Information System (GIS) with Applications for Data Query and Statistical Analysis
620	Collection and Archival of Environmental Data Relevant to Design of Arctic Structures

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Last Updated: 08/08/2008, 01:29 PM