Study Of The Stress Disturbance Of Earth Surrounding Due To Shield Tunneling

The shield method is one of the main ways of underground construction.The shield construction method has advantages over other construction methods in controlling ground settlement,noise and vibration,and environmental pollution.It has received great attention from people and has been able to develop rapidly.Correspondingly,the disturbance of the shield by the shield during the excavation process is also a focus of attention.This paper mainly studies the characteristics of stress disturbance of surrounding soil by shield tunneling.It consists of three parts:1、Regarding the scope of disturbance caused by shield tunneling,domestic and foreign scholars have different ways of dividing them based on different criteria.The existing method for determining the degree of stress disturbance considers only the distance to the tunnel,and does not take into account the depth and the shield diameter.Based on the existing researches,this paper improves the method of determining the degree of stress disturbance and makes the calculation result more reasonable.2、In this paper,through the test and research on the shield tunneling of the south section of the No.8 line in Nansha District of Guangzhou City,the detailed data of the pore water pressure during the shield tunneling process of the three sections were obtained,and the data analysis was conducted.The related phenomena and laws.According to the test results and comparison with other people’s test data,it is obtained that: the pressure of the silo will directly affect the level of the super-hole pressure stress at the measurement point;in the slurry shield,the pressure of the silo-water tank will make the deep measurement point show more than the shallow measurement point.Larger super-hole compressive stress levels,but this phenomenon is not obvious enough in earth pressure shields;the size of grouting pressure will directly affect the super-hole compressive stress level at the measuring point.3、For the disturbance of the shield by the construction of the soil,the predecessors have performed the calculation and analysis of the hole expansion theory in the semi-infinite space.Based on previous studies,this paper has improved the corresponding algorithm to make the calculation result more reasonable.Accuracy,and formulate the corresponding parameter curve for reference when solving.At the same time,the results of the proposed method are compared with the finite element calculation results.The results not only show that the accuracy of the solution is high,but also verify that the solution of the holeless boussinesq solution instead of the hole can guarantee the accuracy.The above study can be used as a different method to analyze the disturbance of soil in shield construction.