Abstract:For the construction of pressure tunnels and underground projects in greater depth,it is necessary to understand the groundwater permeability of the surrounding rocks. Under high water pressure,various weak structures such as joints or cracks inside the rock mass may split or extend,which may lead to permeability change in turn. Therefore,it’s necessary to measure the permeability of surrounding rock under pressures equal to or higher than the designed pressure magnitudes to obtain more reliable permeability information under normal project operation conditions. This paper presents a high pressure permeability measurement technique in boreholes and its application for pressure tunnels.