2.2 Shaking table test

The shaking table at the Traction Power State Key Laboratory is the main facility for experimental research into earthquake engineering at Southwest Jiaotong University. The model test adopts the bi-directional seismic shake table, which table size is 2.5 m by 2.5 m, the platform capable of carrying a maximum payload of 30t and the vibration mode is for X, Y two direction and four freedom degrees. The frequency range is 0.1 ~ 30 Hz, and the peak acceleration of X or Y direction is 1.0g respectively. It is driven horizontally and vertically by four 20kN servo actuators giving full control of motion of the platform in 4 DOF simultaneously.

3 Design of model test similar parameters

Taking into account the model border effect, the width of the box model should be more than 6 times the tunnel width, thus the similar parameters are determined(geometry similar CL =30, Young’s modulus CE = 45, density Cρ =1.5) and Shen (2008) described the rest of physical similar parameters.

3.1 Design of similar material for surrounding rock and secondary lining

According to the similar relation and the physico-mechanical parameters of surrounding rock in situ, the similar material selected is consisted of flyash, river sand and oil after the orthogonal tests are repeated dozens of times. At last these similar material will be mixed according to a certain similar ratio.

The secondary lining material selected is consisted of plaster, quartz sand, barite, water by a certain percentage of preparation, which mechanical parameters are shown in Table. 1.

Table.1 Mechanical parameters of concrete similar material

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