Research On Shaking Table Test Of Multilayer Interchange Tunnel

Currently existing theory and study on anti-seismic of underground structure are mainly for regular structure; research for shallow buried and complex structure during engineering is less. The reconstruction project in ding huai men street of Nanjing city as the underground interchange project in the city, the project adopted for the first time design of using double-deck both on the main line and abroad line. This paper set the double-deck tunnel appearing in the engineering as the research object, design and complete the shaking table test of complex nodes, study on the seismic response of shallow buried complex structure in the process of earthquake.First of all, this paper discusses the significance of researching on the underground structure vibration response; introduce the common types of damage to underground structures and underground structure model test methods:centrifuge test, shaking table test; introduces the theory of similar design of model test, similar design according to model structure and model soil two different materials is introduced.In view of the shaking table test plan, preparation and design process, research the shallow buried structure shaking table test technology, including the choice of box, model structure’s design and making, the production of model soil, instruments and sensors and so on. The test was carried out for the model test data. Analysis on the shallow buried underground complex structure in the acceleration and strain change under ground motion.The main conclusion:(1) The existence of underground structure will change the transmission of seismic wave in the soil, increase the peak acceleration response. (2) Due to the existence of diaphragm wall, ensure the structure move with the surrounding soils together, under the action of earthquake ground motion, the peak acceleration at the top and bottom of the structure similar to the acceleration of surrounding soils, slightly less than the peak acceleration of surrounding soils. (3) Under the effect of horizontal to the ground motion, the seismic response of underground structure is controlled by the surrounding soils, therefore, strain mainly concentrated in the lateral wall and floor intersect. So the middle plate strain response is significantly greater than other parts of the structure. This plate appear damage under 300gal earthquake action. (4) For shallow buried tunnel, under great ground motion, the structure has a rise trend, this may cause to the damage of upper part of the foundation and roads, houses, etc, this should be pay attention.