Xue Feng Shan ground stress report in English3-D INITIAL GEOSTRESS REGRESSIVEANALYSIS OF XUE FENG SHAN TUNNELChina Communication 2nd Highway Surveying Design and Research InstituteApril 2002Written b

the accuracy and reliability of in situ measurement results need to be evaluated and verified by other methods. Therefore, it is necessary to carry out a comprehensive analysis of geostress field using various methods, such as numerical simulation, theoretical analysis and empirical formula. This report presents the initial geostress regression analysis of Xue Feng Shan tunnel based on the data obtained from in situ measurement and other sources.

2. INTRODUCTION

Geostress is an important factor affecting the stability of rockmass and the safety of tunnel construction. The magnitude and distribution of geostress are closely related to the geological and tectonic conditions of the rockmass. In order to ensure the safety and stability of tunnel construction, it is necessary to have a comprehensive understanding of the geostress field. In this study, we use the in situ measurement data and other sources to carry out a preliminary regression analysis of the geostress field in Xue Feng Shan tunnel.

3. GEOSTRESS MEASUREMENT AND DATA PROCESSING

The hydraulic fracturing method is a commonly used method for in situ measurement of geostress. In this study, we carried out geostress measurement in three boreholes, namely K3, K4 and K5, with a total of 28 measuring points. The measurement results show that the maximum horizontal stress is about 8.5 MPa, the minimum horizontal stress is about 5.5 MPa, and the vertical stress is about 16 MPa. The geostress field is characterized by a middle geostress horizontal state.

4. NUMERICAL SIMULATION AND THEORETICAL ANALYSIS

In order to further understand the geostress field in Xue Feng Shan tunnel, we carried out numerical simulation and theoretical analysis based on the geological and tectonic conditions of the rockmass. The results show that the geostress field is affected by the geological structure and tectonic stress field. The horizontal stress is mainly controlled by the tectonic stress field, while the vertical stress is mainly controlled by the weight of the overlying rockmass. The distribution of geostress is influenced by the location and orientation of the faults and joints in the rockmass.

5. CONCLUSION

Based on the in situ measurement data and other sources, we have carried out a preliminary regression analysis of the geostress field in Xue Feng Shan tunnel. The results show that the geostress field is characterized by a middle geostress horizontal state, and is influenced by the geological structure and tectonic stress field. In order to ensure the safety and stability of tunnel construction, it is necessary to carry out a comprehensive analysis of the geostress field using various methods, and to take appropriate measures to control the geostress during the tunnel excavation process