Rock bonded micropiles are quickly becoming the first choice solution for deep foundation challenges with designers utilizing this solution more and more each day. Coastal Drilling East can attest to this rise in popularity and application since the demand for this solution by our customers has increased dramatically. The demand has been driven, in large part, by use in urban areas and as a direct result of the flexibility and relative ease of installation. These small diameter, drilled and grouted-in-place foundation elements offer a wide range of applications and have a proven track record with use on wide variety of projects.
Like most micropiles, rock bonded micropile designs are as diverse as the geological conditions in which they are installed. Rock socket diameter and depth are key elements in optimizing this capability and are greatly influenced by the in-situ geological characteristics. Casing wall thickness, the size of the grade of threaded bar and grout strength will all be considered when customizing the design to ensure the rock bonded micropile meets or exceeds the project specifications.
These micropile designs are tailored to meet the specific performance requirements of any ground stabilization project.
Applications for this capability range from high compression loading used to support parking garages, high rise structures, bridges and other such structures, to tension capabilities that stabilize up-life loads such as wind turbines, large utility poles, mine conveyors and silos. They can also be utilized for load transfers from unconsolidated overburdens or challenging subsurface bedrock like Karst conditions. This micropile type is drilled through the overburden and into competent subsurface rock formations where a rock socket is created. This socket becomes an integral part of the micropile with the addition of threaded bar and grout.
Design engineers can take full advantage of the subsurface rock formation to maximize the structural contribution of the bonded rock socket and optimize the micropile design. The following demonstrates just a small sampling of the successful projects having rock bonded micropiles as part of the foundation: