U.S. Capitol Utility Distribution Tunnels

WDP has performed annual structural condition assessments of approximately 3-miles of reinforced concrete utility tunnels on behalf of the Architect of the Capitol since 2006, under multiple term contracts. These assessments use visual and sounding techniques to identify, quantify, and document the extent of the damage. Both destructive and nondestructive testing techniques are used to characterize material properties, including chloride concentrations, electrochemical corrosion measurements, and concrete strengths. Structural analysis is performed on critical sections, and restoration recommendations, including cost estimates, are provided. WDP has completed 20+ projects since 2006, including continued annual condition re-assessments as a part of WDP’s recommended maintenance plan. Repair projects are prioritized within budget constraints and include restoration of concrete and steel supports due to corrosion, injection of cracks, expansion joint repair, curtain grouting to address water infiltration, and design of supplemental steel supports. Construction support services are provided for these projects, which include periodic site visits and attendance at coordination meetings, review of contractor submittals and RFIs, reaction to unforeseen conditions, and updating as-built documents. These services provided continue to improve and maintain the critical utility tunnels and prioritize safety for tunnel entrants. This work requires site-specific safety training—including confined space access, asbestos awareness, respirator use, and emergency evacuation and response.