The Three-dimensional Model Test On The Earthquake Dynamic Response Of Huangcaoping Tunnel No.2 Of Sichuan-Tibet Highway

With the implementation of Development Strategy of West of China, a lot of tunnels for highways, railroads, hydropower projects will be built near the active faults or in the strong seismic regions. Does the dynamic response of mountain tunnel accord to any rules under the strong earthquake? Is the security of tunnel enough when it is constructed near the active faults or in the strong seismic regions? How to alleviate the effect of earthquake though advisable design? All these are concerned problems puzzled project designer. The study of earthquake resistance design for the tunnel and underground engineering has just begun at present time in China. It is of great actual value to study the seismic responses and the vibration-absorption measures of the shallow buried mountain tunnel built in the strong seismic regions. This paper aims at exploring the law of tunnel in response to the earthquake dynamic profoundly by large-scale shaking table test on opening section of Huangcaoping tunnel No.2.On this paper, drawing Huangcaoping Tunnel has been carried out by small vibration table model test of the geometry derived similar to 1 / 40, bomb-similar to 1 / 15, the density similar to control than 1/0.75 similar to the various factors; To barite powder, quartz sand, zinc oxide, gypsum, glycerol, latex and water to the substrate, in accordance with different materials than the preparation of the mixed Huangcaoping tunne as a grade II, III surrounding rock similar material; within Purchase steel mesh tube as the plaster lining the tunnel structure model; initial support structure will be simplified for different diameter of the wire to simulation, and the model of the static and dynamic mechanics of the test parameters, such as various research results Based on the dynamic response of a large-scale earthquake shake table physical simulation experimentsWith reference to have the various physical modeling experiments based on the design of an experimental model of me so as to meet the model of the natural frequency requirements by shaking table size and model of the control of the border established model to simulate size; selected for this experiment Various testing equipment and laying, installation of equipment, methods. Completed the design in accordance with the above model of conservation and pouring concrete to form a simulation of the production process.Commissioning test equipment to be imported after the white noise scan to identify characteristics of the model, according to install the system to load test the design, respectively, from weak seismic waves enter Xeon.On the three-way and six degree of freedom shaking table ,the Huangcaoping 2 # tunnel entrance of the model was 63%, 10%, 5% and 1% exceeding probability , different exciting direction seismic waves enter the shaking table test. To test of universal significance, the test measured by adding a natural wave,is Kobe wave. Earthquake simulation test process, in addition to sensors tests, also used the camera to monitor the entire process, and in every condition enter the tunnel lining after the scan, observed deformation and damage the lining situation.Conditions will be collected to the various acceleration curve, the strain curves, and the stress curve analysis: Exciting different seismic impact on different direction of the tunnel, to the Y, YZ exciting to undermine the structure of the tunnel when the largest tunnel with depth Dynamic Response dwindling, in more than 10 times the value of tunnel Diameter after the dynamic response has stabilized; bias backing the side wall of the tunnel dynamic response than the invading side wall; damping layer, the seismic shock absorption, such as joint measures to damping Effect; portal corner of the invading side in the earthquake and its role under stress concentration, the portal for the most vulnerable to damage the region; slope in the cave under the dynamic load, front slope in the region did not support a number of tension cracks, but not Instability in the overall, only a partial block out the phenomenon.Finally, the physical simulation test results, digital simulation results, on-site monitoring of a comprehensive analysis of information on seismic safety evaluation of the Huangcaoping 2# tunnel.