AES Environmental Consulting

Sinkhole Investigation & Remediation

Central Pennsylvania is underlain by solution weathered limestone that contains cavities and voids that range in size from a few inches to more than 100 feet wide and high. The sinkhole dotted surface of the limestone is typically buried beneath thick deposits of overlying sediments, thus the foundation hazards associated with building above the limestone are generally not visible from ground level.

Surficial stormwater from the upper sediments flows downward through cracks or breaches in the confining clay layer, carrying soil into cavities within the limestone, (this process is called “piping”). Significant piping can create a void in the overburden soils. When this void enlarges to a size at which the overlying soil can no longer support itself, the “roof” of the void collapses resulting in a sinkhole of the ground surface. When the overburden soil lacks a cohesive structure and the available void space in the limestone is small, the settlement is more gradual. In either case, the effects on structures which are positioned above or very near the sinkhole are potentially very damaging. Proper exploration and engineering is, therefore, critical to evaluating sites for development and construction.

aes‘ philosophy is to first consider the risk posed by the carbonate geology hazards as they relate to subdivision plans. For example, the investigation and mitigation of sinkholes in an isolated outlying portion of a subdivision should require significantly less time, money, and effort than sinkholes located under an occupied structure. Secondly, aes‘ experienced professionals know that in order to truly deal effectively with carbonate geology, the identification of the mechanisms that are causing, or may cause, concern for the proposed subdivision. This allows for the development of appropriate designs that consider the risk posed by the formation carbonate geology features.