DA Smith is experienced with drilling, coring, and pressure-grouting holes in concrete arch and gravity dams across the United States. Past projects have involved core drilling to investigate concrete integrity and bedrock contact, installation of geomechanical instrumentation, concrete sampling for mechanical properties testing, and in situ stress measurements inside dams. We work with private dam owners, government owners, engineering firms, and heavy civil constructors, and can adapt our equipment to fit virtually any project.
We have the capability to drill in difficult-to-access locations on the crests of dams, on barges, from scaffolding on dam faces, below gates, on spillways, and inside narrow tunnels, galleries, and shafts inside dams. We are experienced with many forms of hole grouting and the use of non-shrinking low-alkali grouts and plasticizer compounds where historical concrete may be vulnerable to alkali-silica reaction.
We are capable of coring through any dam and into bedrock at any angle, reaching hole depths of more than 1,000 feet, depending upon core size. We are also able to core through structural steel if necessary. We routinely core N, H, P, and 6-inch-diameter, and have cored up to 18-inches in diameter where large samples were required.
We have extensive experience drilling into high-pressure regimes where flow control is critical and can fabricate special containment and flow control systems for sites where water contamination, dam breaching, or inundation is a concern.
DA Smith offers extensive experience drilling in transportation, mining, and water tunnels for geotechnical characterization during construction to post-constructing investigations. We can core N, H, P, and 6-inch-diameter at any angle inside a tunnel, or plug drill where coring is not required. Our skid-mounted drills can be transported readily by wheeled equipment or rail in most tunnels, and our larger track-mounted drills are self-tramming. Our permissible drills are MSHA certified and can operate in gassy environments. Our services can be designed to fit almost any tunnel project.
Our smaller equipment can fit inside wet or dry tunnels as small as 7 feet in diameter and is fully self-contained where utilities are not available. Our tighter equipment oftentimes facilitates closure of just one lane of traffic in live-traffic tunnels.
Where high-pressure and/or high-volume groundwater is a concern, we have the ability to set surface casing and drill through a sealed flow-diverter with shut-in pressure capacity up to 200 psi (1.4 MPa). Holes can be completed with casing of any design and pressure grouted to control water or gas flows.
Where contamination is a concern in water supply tunnels, we are able to drill with water (no drilling additives) and our rigs are ordinarily operated with biodegradable (food-grade) hydraulic oil that poses no environmental harm.