Internal Force Analysis Of Straight Arch Tunnel Wall

Arch lining vertical wall tunnel is one of typical underground engineering structures.The engineering properties(geological conditions and construction factors,etc.),design principles and methods of tunnel structure are completely different with the ground structure.In this paper,in order to discusse internal force and deformation of arch linging vertical wall tunnel,two methods are adopted to caculate internal force of tunnel which is under the main initiative load(rock pressure) and passive resistance(elastic resistance).Based on continuous Winkle assumption,load-structure methodit is used spring to simulate the interaction between structure and surrouding rock;By means of determining the scope of surrounding rock which influences in the tunnel structure,FEM is to establish overall model(continuum model).The comparison of two methodsis shown:(â…°) Displacement curve is similar in two methods,but the former is larger than the latter;(â…±) The main displacement of the structure is occurred in the y-direction,in the meanwhile,the entire structure is compressed,and the maximum displacement is occurred in the part of ring;(â…²) Comparised to compression range,there is very small range in tension which exists in lining reinforcement region and the bottom of the foundation;(â…³) Stress concentration appears at the foot of the wall beacause of the largest structure moment;(â…´) Stress and deformation of the structure is increasing with the increase of depth.By both surrounding pressure and elastic resistance in the load-structure are assumed, it can not reflect the fact well and its results are often largerer;By means of FEM,the whole model consists of the surrounding rock and structure can reflect their interaction,it can be considered integrity as well as the interaction of rock and structural,but its result is too idear,so it is differrent from the actual situation.In addition,it is suggestion that the wall foundation should be smoothed to to reduce the stress concentration.And the size of wall section should be increased.Lining size should be reduced in engineering project for the part of side wall and the arch with the very small force and deformation.