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Skilled engineers, knowledgeable scientists, innovators, and members of the community. Our commitment is both professional and personal. Shannon & Wilson staff play key roles on project teams for high profile projects in the cities in which they live, and the world at large. Some of our current projects are featured here. |
The city of Fort Smith’s raw water supply requires an additional firm yield capacity of 25 million gallons per day to meet the water demand for the year 2040. The most cost-effective alternative for meeting the future demand is to enlarge Lake Fort Smith Dam and Reservoir and eliminate the upstream Lake Shepherd Springs Dam. The expansion and combination of the two lakes is being accomplished by enlarging the Lake Fort Smith Dam from existing top of dam elevation 845 ft. to elevation 946 ft. Portions of Lake Shepherd Springs Dam material were removed and used in the construction of the enlarged Lake Fort Smith Dam.
Working closely with Burns & McDonnell, Shannon & Wilson provided the initial geologic reconnaissance, geotechnical investigation and design, and is currently providing construction monitoring services for this technically challenging project. Subsurface conditions were investigated for the existing main dam; the foundation of the new, enlarged dam; principal and auxiliary spillways; the intake tower and outlet works tunnel; removal of the upstream dam; and borrow areas.
For more information on the project, visit the Fort Smith Utility Department website .
Alyeska Pipeline Service Company has contracted the Shannon & Wilson Fairbanks office to assist them with an assessment of the liquefaction hazard of selected slopes along the Trans Alaska Pipeline (TAPS). We are also assessing and monitoring the stability of several slopes underlain by discontinuous permafrost along the pipeline system. Our monitoring program includes visual observation and instrumentation of the slopes with inclinometers, thermistor strings, piezometers, and GPS monuments.
Our Fairbanks office is also providing recommendations regarding the design and replacement of aboveground thermal support structures in areas underlain by permafrost along the pipeline.
To find out more about pipeline engineering, you can visit the Alyeska website .
Shannon & Wilson’s Anchorage office assisted with onshore and offshore explorations, laboratory testing, and provided engineering support for preliminary engineering work for the proposed bridge connecting Port MacKenzie with Anchorage, Alaska. The project included a 24-hour drilling program and collection of soil samples from a “jack-up” barge in the Knik Arm for conceptual design of pile supported bridge structure and granular fill approach embankments. Deep, soft, clay sediments were sampled and tested for strength properties in the Shannon & Wilson Anchorage laboratory. Onshore geotechnical explorations included approximately 150 subsurface investigations along existing roads as well as undeveloped areas and shoreline explorations. The alignment or “footprint” of the portion of the project crossing Knik Arm has now been fixed through environmental permitting studies and the project is moving into the design development stages. Shannon & Wilson has been contracted to remobilize the “jack-up” platform and will be conducting offshore geotechnical explorations along the project alignment during July and August 2006. Information gathered from this field program, and additional testing of samples recovered during drilling, will be compiled into a geotechnical data report to share with prospective bidders in a design/build style bid procurement.
For more information on the project check out the KABATA website.
Based on the results of a recent study we completed in the former peat bog area of the cityÂ’s Greenwood neighborhood, the City of Seattle Department of Planning and Development (DPD) will be reviewing new development projects with the goal of limiting the withdrawal of groundwater both during construction and from permanent development. For more information on our study, and its results see the DPD website.
We have been providing services on the design build team for the new mile long suspension bridge to be constructed 200 feet south of the existing Tacoma Narrows Bridge in a narrow channel in Puget Sound. Highlights of our work have included:
Subsurface explorations, including drilling marine borings in over 150 feet of water that extend up to about 200 feet below mudline. The deep water, significant tidal changes, and extremely fast currents that approached 10 knots complicated the explorations.
Development of the ground motions for seismic design of the structure. To develop the ground motions, we made a comprehensive assessment of the seismicity of the area, performed probabilistic seismic hazard analyses (PSHA), and developed both earthquake time histories and spectra for design of the bridge.
Fast-track permit application and acquisition for the in-water geotechnical field explorations and borings, in order to work during the optimal fieldwork season and state fisheries closure windows. All the federal, state and local permits and exemptions were obtained in record time.
Emergency response after a 100-year storm event to identify critical erosion mitigation areas and provide recommendations for repair and protection.
For more information on the project, check WSDOT’s website.
Shannon & Wilson has been providing geotechnical, environmental, hydrogeologic, and seismic services as part of the team developing alternatives for the replacement of the aging viaduct structure along the Seattle waterfront. Read about this critical project on WSDOT’s website.
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