Borehole Wall Stress Relief Method(BWSRM), the new ground stress test method put forward by scientist in China, is already wildly applicated in major projects in our country, horizontal hole ground stress logging robot matching the new method is also developed successfully.
The achievement is leaded by Ge Xiurun, academician of Chinese Academy of Engineering, professor of Shanghai Jiao Tong University, researcher of IRSM(Wuhan),CAS. To reach the target, he worked together with many research institutes and scientific researchers from enterprises for more than 10 years, during the period, the project wins financial support from the key program Ya Long Jiang Joint Research Foundation of National Natural Science and Technology Foundation of China, The General Program of National Natural Science and Technology Foundation of China, The Fundamental Innovation Foundation of Chinese Academy of Science and 985 program of Shanghai Jiao Tong University. From August 7 to 12 in 2010, with the ground stress logging robot they developed, the team leaded by Ge Xiurun run the first ground stress practical measurement in the underground tunnel with depth of 2430m, on the construction site of Ya Long Jiang Jingping second-cascade hydropower station in Xichang City, Sichuan Province, the measuring test succeeded. The basic principle of BWSRM ground stress measurement has been published on the International Symposium on In-situ Rock Stress, 19-21 June 2006, Trondheim, Norway, it is printed on the meeting work collection, page 185-192.
The horizontal hole ground stress logging robot is in cylindrical shape, the external diameter is 148mm, the length is 720mm, the weight is 21 kg. After being pushed to the predetermined depth, the robot could accomplish equipment anchor location, partial wall surface buffing, cleaning and drying, spraying glue spread to the operation side, automatically paste strain gauge, drilling tool automatic recovery and so on. The data is collected automatically by the computer for following analysis and treatment. The whole ground stress test process is monitored and controlled in real time by computer.
Jinping second-cascade hydropower station mainly takes advantage of the 150km natural fall of Jinping, excavate tunnel and generate power with the water. The project plans to install 8 units, with the power of 600MW each, making 4800MW in total. The buried depth of deepest part of diversion tunnel is the same as ground stress real time test buried depth, therefore, the test is with great significance. It has filled the gaps of ground stress real time test. The real time test place we choose is the ideal place where the physics circle is planning to build deep underground laboratory.
