| In recent years,the case of tunnels built by the shield method in China was increasing gradually,and a large number of tunnel projects were distributed in high-intensity seismic region.Under the action of strong earthquakes,the tunnel suffer from various damages,and the post-disaster repair of tunnel is difficult because of complex environment.Therefore,in order to improve the safety of tunnels under strong seismic action,it is necessary to carry out research on seismic isolation technology of shield tunnels.Synchronous grouting as a key link in the construction of shield tunnels,the selection of grouting materials is crucial,and the current research on synchronous grouting materials rarely takes into account the grouting layer as a seismic isolation of shield tunnels,which plays a certain role in shock absorption under the action of earthquakes.Based on the current research results on seismic isolation in tunnel engineering,combined with the synchronous grouting technology of shield tunnels,the performance of grouting materials and the influence of the new seismic isolation on the dynamic response of the tunnel was studied through indoor testing and numerical calculation.The main work of the paper is as follows:(1)Cement,fly ash,bentonite,rubber particles,closed-cell perlite and polyvinyl alcohol fiber are used as raw materials,through indoor testing,combined with the construction requirements of synchronous grouting of shield tunnels,the influence of the each component on the apparent density,consistency,fluidity,bleeding rate,volume shrinkage and setting time of the grouting is comprehensively analyzed.(2)Through the uniaxial compressive test and the flexural test,the failure characteristics of harden body were analyzed,and the influence of each component on the strength of harden body was discussed.(3)Through three-dimensional caculation simulation,the dynamic response of shield tunnel under the conditions of different stiffness and thickness seismic isolation is analyzed. |
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