A STUDY ON EVALUATION OF HYDRAULIC CHARACTERISTICS OF BEDROCK IN UNDERSEA TUNNELS USING FLUCTUATIONS IN PORE PRESSURE

Abstract

 Undersea tunnels are in extraordinary conditions for maintenance in that they are affected by high water pressure. In particular, it is difficult to evaluate the soundness of the bedrock, including the effect of the grout injected because the back side of the tunnel lining is difficult to monitor. In this study, we conducted data analysis and numerical simulation of the measured pore water pressure for the purpose of constructing a method to grasp the state of the bedrock and the grout. As a result of data analysis, the change of the pore water pressure turned out to be affected by tide. Numerical simulation was performed under multiple parameter settings. The parameters that explain the current state of the bedrock inspected from the measured pore water pressure and the fluctuations in pore pressure that occur when the function of the grout changed were determined.