Estimation Method for Geostress Based on a Modified Shoerey Model
(1 Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources, Yangtze River Scientific Research Institute, Wuhan 430010; 2 State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071)
Abstract：
Geostress is one of the basic loads of underground works, and the vertical stress of a rock mass can be calculated using the overburden pressure while the horizontal stress is difficult to determine. The elasto-static thermal stress model established by Shoerey is widely accepted, but the model does not take the tectonic movement induced by regional differences into consideration, and the distribution rules of the horizontal maximum principal stress and minimum principal stress haven′t been obtained. In this paper, Shoerey′s model is modified by introducing the correction factors of regional tectonic stress based on elasticity theory, and an estimation method for horizontal stress in an elastic rock mass is proposed. An in-situ stress and rock mass modulus measurement are carried out for the Meihuashan tunnel, and a comparison between the calculated results and the measured geostress data are conducted. The results show that the prediction error caused by the local geological structure and rock mass homogeneousness is small and within the allowed scope, meeting the precision requirements for engineering.
2017, Vol. 54 