Entergy Services, Inc. hired TWE’s Lake Charles office to conduct a geotechnical engineering study for the Lake Charles Power Station Unit 1 Project at the Nelson Electric Power Generating Facility.


The project site consists of about 14 acres of undeveloped, densely wooded pine grove.  TWE utilized a subcontractor to clear paths for access for our equipment and personnel. Some of our challenges included getting equipment and personnel into the wetlands following Corps of Engineers (COE) guidelines using temporary matting, accessing low-lying terrain, and inclement weather. Major components of the project included two combustion turbine generators (CTGs), two heat-recovery steam generators (HRSGs), three main step-up transformers (GSUs), one steam turbine generator (STG), and one cooling tower.

Our scope of services included soil borings, cone penetrometer tests (CPT), seismic downhole tests, field resistivity tests, hand-augers, and temporary piezometers. Geotechnical engineering assessments included site preparation, shallow and deep foundation recommendations, site pavements, temporary construction yards, and detailed settlement analyses all coupled with a comprehensive laboratory testing program. Laboratory analyses included standard testing such as Atterberg limits, strength tests, and gradations, as well as advanced soil-mechanics testing consisting of one-dimensional consolidations and analytical testing that included soil pH, electrical resistivity, chloride ion concentrations, and sulfate ion concentration for recommendations pertaining to the potential for on-site soil conditions to degrade buried concrete and corrode steel foundation elements.

Although the field work got off to a slow start mainly due to weather conditions, our crews completed all field work in about eight weeks and the report was submitted within budget and by the client’s due date. As a result, we have been notified that we are the top candidate to provide all QA/QC services during construction, which is slated to begin early in 2018 at a preliminary construction budget of $800 million.

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