| Coal is the major energy source in our country. It is one of the world’s top five energy sources today. In Chinese energy structure and economic structure, it occupies a very important position. The ways of coal mining are vertical shaft, inclined shaft, tunnel, integrated mining and so on. It is a revolution in our country for the technology of building mine well to construct the mine inclined shaft by TBM. It has a social, economic and practical significance for the mine safety and efficient production.TBM is an advanced technology which uses full face rock tunnel boring machine for construction. In the long tunnel engineering construction, it has been widely used. It can create a safe construction environment and accelerate the speed of tunnel boring.This paper studies the construction of coal over long distances inclined shield according to the coal mine construction of Shenhua Taigemiao area. According to the different stratas, the slope is divided into four sections along. The3D model is established based on MIDAS/GTS software. It can simulate shield excavation and segment support process. Then we analyze the deformation and stress distribution of tunnel surrounding rock during tunneling. On this basis, segment model will be established in MIDAS/Civil software combining the load structure method. We can get the internal force of the segment. And then check the bearing capacity of the segment using the method of safety coefficient and the limit state design. Finally, we can get the maximum water pressure of the bottom tube sheet of each segment inclined by analyzing segments security. These research results lay a foundation for the shield segment design and construction. The main conclusions obtained in this paper are as follows:(1) After supporting the shield lining segments, a settlement area will appear in the vault of the tunnel. The largest settlement locates at the vault of the surrounding rock. The greater the distance away from the vault, the smaller the amount of the settlement of the surrounding rock is. An uninstall uplift area will appear at the bottom of the tunnel. The maximum uplift locates at the dome of the surrounding rock. The greater the distance away from the dome, the smaller the amount of wall rock uplift is. The settlement area and uplift area will be larger with the shield advancing. Also the maximum will increase.(2) With the shield tunneling, the settlement value of the transverse cross section of the formation model is also increasing. At the enterline of the tunnel, the settlement value is the maximum. The greater the distance away from the centerline of the tunnel, the smaller the settlement value is.(3) The distribution of the formation stress increases ladderly before inclined shaft tunneling. The biggest stress locates at the lowest level. The deformation of the above groud is bigger than that of the below groud. The rock stress will obviously change durning the process of tunnel excavation. The phenomenon of stress concentration will appear in the center of the tunnel.(4) The internal force of lining segment changes with the continuous advance of shield. The maximum bending moment of the segment appears in the arch bottom. The maximum axial force appears in the left and right arch waist. The higher the level of the groundwater is, the greater the value of internal force will become. But the position of the maximum does not appear to change. The safety factor of the same formation will decrease gradually with the increase of water pressure. |
PDF Full Text Request