The Study On Temperature Evolution And Dynamic Characteristics In Meso-scale Of Soil Around Cross-river Highway Tunnel

With the rapid development of urbanization, the cross-river tunnel traffic has been paid great attention and developed in Cities along Rivers. The cross-river tunnel highway traffic is gradually becoming the main form of cross-river traffic, because its advantages of no blockage of navigation, atrocious weather immunity, low turbulence to environment and so on. During the operation period, soil surrounding tunnel is under persistent disturbance, such as traffic induced heat conduction and vibration. In this paper, the thermal response of the soil surrounding tunnel and dynamic characteristics of sand substratum are studied, In-situ tests and numerical methods are both performed, and the related achievements mainly include:Firstly, long term observation of shield tunnel segment at six measured section is carried out, and annual change law of shield tunnel segments is revealed. The3-dimension heat transfer numerical model of shallow-buried Section of the cross-river tunnel is established, the measured temperature of ground surface and tunnel segment are applied as boundary conditions. The simulation results are compared to measured data to verify model reliability, and the variation law of temperature surrounding tunnel in different space-time condition is analyzed.Then, a discrete element method named particle flow code in2-dimension is used to establish numerical sand sample of the substratum and simulate the sand behavior under drained cyclic loading. Base on the results of lab tests, the micromechanical parameters for the simulation are achieved. The effects of consolidation process, mean normal stress and cyclic stress amplitude are investigated. The evolution of coordination number and contact force are described to explain the macroscopic shear properties.