Authors: ZHAO Yu-fei *, WANG Yu-jie *, ZENG Xiang-xi **, HE Chuan-yong *

* Geotechnical Engineering Department, China institute of water resources and hydropower research, Beijing 100048, China
** Mid-South design and research institute, CHEGG, Changsha 410014, China

Abstract: Xiangjiaba hydropower station is the last hydropower station of the water resources cascade development on Jinshajiang River. The geological condition of Xiangjiaba hydropower station dam foundation is very complicated. The foundation rock’s lithology is fluvial and lacustrine facies sedimentary rocks. And the lithologic facies of foundation rock change greatly and bedding’s condition is very complex. How to evaluate the rock mass quality and determine the rock mass engineering mechanical strength parameters is a very important problem. During the dam foundation testing of Xiangjiaba hydropower station second phase project, we did several groups of rock mass bore shear testing in black mudstone in the dam foundation, using the test equipment from the Iowa state university of America. And we got the rock mass shear strength parameters from the rock bore shear testing data by utilizing the least square method. The test data has a very high linear correlation. Generally, the correlation coefficient of σ and τ is 0.90, even 0.98. The rock mass bore shear test in the Xiangjiaba hydropower station dam foundation illustrates several benefits of this test, which are convenient and fast, the high correlation of the test data and the reliable rock shear strength parameters. And the rock bore shear test has a good adaptability in the geotechnical engineering and it can give a powerful technical support to the project decision.

Key words: rock bore shear test, Xiangjiaba hydropower station, shear strength parameters

Published in: Journal of China Institute of Water Resources and Hydropower Research, Vol. 9, No. 3, 2011

Article ID: 1672-3031 (2011) 03-0237-06