Managing Ground Deformation Risks on Underground Construction Projects in Urban Settings

An increasing number of soft ground tunnels are built in urban environments where it is crucial that existing infrastructure be protected from potential ground deformations resulting from construction. An important component of protecting this infrastructure is implementing best practices to engage third-party infrastructure owners and develop a ground deformation mitigation plan to ensure risks are fairly allocated among all parties. This approach requires early and close coordination between the project owner and the third parties. During solicitation of a project’s construction contract, coordination should have already occurred and agreements concerning infrastructure protection requirements, included in the bid documents. This allows bidding parties to be aware of the agreed third-party requirements and allows accurate risk and cost assessment. After contract award, monitoring procedures and reporting protocols are important to keep third parties informed. This paper presents the best practices used on the DC Water Clean Rivers Project.