Research On Load Distribution Of Shied Lining In Chengdu Metro

There is an important city in the west of china named chengdu which has several million of people, where economy develops very fast. Urban Transport has a big influence on people's life and the development of city. Today, urban rail transit is considered as the effective method of solving the traffic jam in the city. In order to solve this problem, chengdu metro line one has been built which would be expanded to the whole city. In general, shield tunnelling method is used in the construction of the metro. The shield linings, as the finial supporting structures of the tunnel, have an important effect on the safty and durability of the all tunnel . if we can get the load distribution on the lining clear, it would be much helpful to the design of the lining and would generate significant economic results.The geologic situation in chengdu is sandy pebble with much groundwater which is different from other places. What's more, the level of groundwater changes along the change of seasons. It is the first time of building the shield tunnel in this geologic situation. There is little construction experience we can use for reference. There is much challenge in the design and construction of the metro.The load distribution on the lining is researched in this paper based on chengdu metro line one , the specifics as follows:(1) monitor the earth pressure and water pressure on tunnel lining , the strain of concrete and the axis force of steels in the lining, then calculate the internal forces of the lining;(2) suppose four different load distributions and calculate the internal forces based on each distribution to get the curve between the load and the force; then do the dynamic analysis according to the internal forces of the lining; at last , get the. better load distribution for the lining in chengdu metro;(3)calculate the internal forces under different levels of groundwater according to the special load distribution on lining ;then make comparison between it and the real forces of the lining in order to compute reinforcing quantity ; at last , give the advice for optimization.