CLEARWATER DAM MAJOR REHAB PROJECT, PHASE 1B COMPLETION OF EXPLORATORY DRILLING AND GROUTING
Advanced Construction Techniques was awarded the project by the U.S. Army Corps of Engineers Little Rock District through a Best Value RFP Selection process. This work was a continuation of Phase1 completed in October 2007, however under a new contract. The scope of this contract was to complete the foundation rock treatment down to elevation 325, 250 ft below the working platform, prior to the installation of the proposed cutoff wall. The lower 50 ft of the grout curtain is to be grouted to a value of 3 lugeons or less and the upper rock mass to a value of 10 lugeons or less. The work included sonic overburden drilling, DTH water hammer percussion rock drilling, borehole directional survey, video imaging, borehole washing, permeability testing, pressure grouting using balanced stable cement grout mixes and low mobility grouting of karst solution features.
IntelliGrout®, a proprietary computer monitoring system was utilized for real-time electronic monitoring and recording of the permeability testing and grouting. IntelliGrout® provides powerful analytical and graphical tools for production grouting analysis. The system is integrated with AutoCAD and provides never before available graphical representations of water testing and grouting data for closure analysis. The data was uploaded weekly to the IntelliGrout® Website allowing all project participants access to the data remotely.
A 40 to 60 foot (12-18 m) thick permeable soil layer below the dam embankment materials and above the rock foundation was identified during the project. Tube-a-manchettes (TAM), or sleeve port grout pipes, were installed in order to facilitate treatement of this zone. Permeation grouting was performed to successfully treat this unique feature using cementitious grouts. The permeation grouting was also monitored using ACT’s IntelliGrout® system.
Client: US Army Corps of Engineers, Nashville District
Owner: US Army Corps of Engineers, Nashville District