| Shifangyu tunnel is deemaed as the research object in this study.With the investigation of the modeling and simulation technique of tunnel construction,the optimizaion construction of this tunnel is carried out in detail.The design and construction of small interval tunnels,the construction mechanics of Small Spacing Tunnels and the monitoring and measurement technology of tunnel construction process are summarized systematically.On this basis,the paper focuses on the modeling method of small spacing tunnel structure and surrounding rock,Xiaojing.The numerical simulation technology of tunnel construction process,the optimization of Shifangyu tunnel construction scheme considering the variation of surrounding rock physical parameters and the evaluation of Shifangyu tunnel construction optimization scheme based on monitoring data are studied.By combining the engineering survey and geological survey data of Shifangyu Tunnel with the stress release law of surrounding rock and the finite element modeling theory of tunnel structures such as loosening zone and pressure arch,the finite element modeling of V-class shallow-buried small clearance section of Shifangyu Tunnel is carried out.Based on the finite element modeling of Shifangyu Tunnel,three construction methods,step method,multi-arch step method and multi-arch mixed method,are designed and simulated respectively.By comparing the vertical displacement nephogram and ground settlement curve of tunnel structure calculated by construction simulation,the optimum construction method is selected to realize the construction.The optimization of the construction plan for the Shi Fang Yu tunnel is presented.The construction scheme of Shifangyu Tunnel is designed in detail with the selected construction method,and the contents and frequency of the monitoring and measuring items are determined.Then,the measured data of ground settlement,horizontal convergence and vault settlement of the tunnel are sorted out,which corresponds to the construction simulation results.In order to verify the accuracy of the construction simulation results of Shifangyu Tunnel and to evaluate the deformation degree and safety of the surrounding rock and diagnose the structural state of the tunnel,the co-mapping is carried out.The results show that the tunnel measurement results under the proposed construction scheme conform to the expected stable development trend,the deformation of surrounding rock can be stabilized to a basic stop within the expected time,and the simulation results are in good agreement with the established construction simulation results,which proves that the tunnel construction process simulation is more effective. |
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