Subsidence Mitigation

Our staff has performed several million dollars worth of subsidence mitigation projects.  These services generally pertain to mitigating subsurface voids left behind from historical underground mine workings.  Western conducts extensive research to determine what information about the mine workings exists to complete these projects.  Western evaluates risk to determine if any buildings, infrastructure, or people are at risk of being damaged or hurt.  Once information is obtained and compiled, it is used in conjunction with current survey information to create the project area and design the borehole pattern that will best fill the existing voids.  Once the preliminary design is complete, Western uses exploratory drilling to confirm the accuracy of design mapping.  Production drilling and injection grouting commence once the mapping has been adjusted or confirmed. Western’s role at this point in the project is to inspect drilling and grouting operations to ensure that they meet project plans and specifications and test the grout before pumping to confirm that it meets the properties set forth during design.  Western also performs construction management on behalf of the client throughout the project.  Construction management generally consists of preparing bid documents, conducting bid tours, prequalifying potential bidders, reviewing bids from qualified contractors, drilling inspection, e-log interpretation, grout inspection, and reviewing and approving the contractor’s pay applications. Having read thousands of e-logs, Western can quickly interpret these logs to assist the contractor in their grouting operations.  Inspection during the project allows Western to make adjustments and recommendations to the contractor, ensuring that the area has been effectively mitigated.  Western can perform other functions such as documentation, as-builts, and special exploratory techniques such as down-hole video.