Study on Bearing Characteristics of Surrounding Rock of Tunnel-type Anchorage under Deep Cutting

According to the specific engineering geological background of tunnel-type anchorage under the excavation cutting on the North Bank of Youxi Yangtze River Bridge, in order to study the bearing characteristics of the shallow burying tunnel-type anchorage surrounding rock, the comprehensive research method is used to study the deformation and bearing characteristics of the tunnel-type anchorage. The method includes the evaluation of geological and mechanical properties of surrounding rock, the prediction of engineering experience model, the numerical simulation of finite difference and the verification of field model test. The results show that the prediction result of engineering experience model is the lowest, which is 10.2 times design load. And the ultimate bearing capacity obtained by model test loading is 18 times design load. Furthermore. The bearing capacity obtained by numerical simulation is 11 times design load, which is consistent with the yield strength of bearing capacity obtained by model test. To sum up the above, the three methods comprehensively show that the bearing capacity of tunnel-type anchorage surrounding rock meets the requirements of the specification for the safety factor of surrounding rock stability and has a certain optimization space. In addition, the research methods and results are all example for tunnel-type anchorage construction of bridge under similar geological conditions.