Response Analysis Of Utility Tunnel Under Fault

In the process of urbanization,utility tunnel is playing an increasingly important role,providing the space for laying and maintenance of the various pipelines which guarantee the normal operation of the modern city and even more provide a shelter for the pipelines to resist the destructive effect from outside space to a certain extent.It was researched that the damage degree of underground structure is as the same as the surface structure,especially for the long-distance underground structure under the circumstance of large deformation motion,such as the fault rupture,soil liquefaction,caused by the earthquake,which makes huge economic losses and affects the normal development of human society.In this paper,the seismic response behavior of the utility tunnel under fault caused by earthquake is studied and the damage process is analyzed,providing the theoretical and technical support for the design and construction of the utility tunnel under the fault rupture caused by the earthquake.The main work of this paper is as follows:1.The damage characteristics of buried structure system and utility tunnel in the process of earthquake are analyzed systematically,and the response law and feature of utility tunnel under earthquake action are discussed deeply.2.By using ABAQUS software platform,the utility tunnel model of the nonlinear response analysis under the action of fault displacement is established.The material geometric nonlinear characteristic of the concrete,rebar,and soil are considered,same as the nonlinear interaction between utility tunnel concrete and soil,and the initial crustal stress is also considered.3.The response law of utility tunnel under different displacement action caused by reverse fault and strike-slip fault is systematically analyzed.The displacement,stress and strain characteristics of the roof,side wall and partition of the tunnel are specially analyzed,which are the most vulnerable parts of the tunnel.The result shows that: 1)the response of the tunnel is more serious under the displacement caused by the reverse fault than the same displacement caused by other conditions.2)under the same fault,the stress deformation of the tunnel will increase within the increasement of the fault displacement.3)the fault inclination,the width of fracture zone and the depth of tunnel,which are the most important parameters to the response law of the tunnel under the fault,are considered in this paper,showing: the effect of fault inclination on the corridor reaction is significant and in the range of 45°~90° inclination,with the inclination increasing,the tension and compression damage is reduced,but the shear action is enhanced;with the width of the fault zone increasing,the fault influence area is widened;the influence of burial depth on the tunnel response is mainly reflected in the axial stress of the roof and bottom of the tunnel near the fault.The stress increases with the increase of the buried depth,and the damage is easy to occur near the fault,other parameter effect is gradually reduced.Thesis research result shows that choosing the reasonable reinforcement measures and reasonable crossing angle and depth can greatly improve the ability of utility tunnel to resist the faulting destruction,and the conclusions for the disaster design of utility tunnel which cross the fault site provide a good reference.