Groundwater control for the Stratford CTRL station box

Abstract

An actively pumped groundwater control system has been installed to protect the Channel Tunnel Rail Link (CTRL) Stratford box against uplift. This structure is critical to the operation of the railway, and its integrity is dependent upon the effectiveness of the dewatering system. The reliability of the scheme is provided by a combination of the use of simple, proven, water industry technology and a robust power supply and control system. Quantitative risk assessment techniques were used to guide the design process and demonstrate the security of the system. Stratford is a location where groundwater levels have been rising, and the CTRL scheme will contribute to General Aquifer Research Development and Investigation Team (GARDIT) objectives of controlling groundwater level rise in central London.