MTA Bridges and Tunnels – Verrazano Bridge, 2020
Highlights
- Combined use of NOH2O® and Ordinary Portland Cement (OPC) for positive-side, curtain grouting, leak remediation
- NOH2O® formed a waterproofing membrane along the outer boundary of a utility tunnel
- Schedule-driven performance to ensure completion in time for the summer holiday season
Project Overview
The Verrazzano Narrows Bridge Toll Plaza Utility Tunnel has suffered significant water infiltration since its construction As part of an overall bridge rehabilitation program, Sovereign was tasked to ensure the Toll Plaza Utility Tunnel provides a long-term dry environment for existing and future communication, surveillance, and power systems.
Strategy
Sovereign was tasked to design a cost-effective solution and, based on extensive research and development, developed a plan for combined use of OPC and NOH2O® for cost-effective sealing of voids at the interface between the outside of the tunnel structure and surrounding soils/rock to mitigate water infiltration.
Results
Work was successfully completed in 12 weeks, in time for the summer holiday season. OPC cost-effectively filling excess void space behind the concrete tunnel structure, providing a better-defined pathway within which the NOH2O® waterproofing membrane was injected and solidified, rendering the tunnel dry.
