CLEARWATER DAM MAJOR REHAB PROJECT, PHASE 1 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. The contract awarded was to investigate and characterize the limestone rock foundation through a series of exploratory holes and pressure grout the rock foundation to reduce the insitu permeability prior to installation of the proposed permanent cutoff wall to a value of 10 Lugeons or less.
A double row grout curtain was installed extended approximately 250 below the concrete working platform consisting of approximately 100 ft of embankment material and 150 ft of foundation rock. The work include sonic overburden drilling, embankment overburden casing installation, DTH water hammer percussion rock drilling, exploratory core drilling, borehole temperature profiling, borehole directional survey, borehole imaging survey, borehole washing, permeability testing, pressure grouting using balanced stable grout mixes, and low mobility grouting of solution rock features. Interface treatment consisted of installation of a sleeve pipe across the soil rock zone and pressure grouting. An Epikarst formation was identified during the exploratory investigation that required special permeation grout treatment using grout sleeve pipes and high mobility grout.
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.
Client: US Army Corps of Engineers, Little Rock District
Owner: US Army Corps of Engineers, Little Rock District