土压平衡盾构改性砂土流动特性的离散元模拟
DEM simulation of flow property of conditioned sand in EPB tunneling
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摘要: 对运用离散单元法模拟改性土流动特性的可行性进行了分析,提出了改性土离散元接触本构模型,在此基础上对改性土坍落度实验进行了离散元数值模拟。在实验室内对标准坍落度实验进行了改进,坍落度实验数值模拟得到的改性土坍落后的形态再现了实验室结果,并且标记点的垂直位移与实验室实测结果一致性较好。Abstract: The feasibility of the discrete element method(DEM) simulation of the flow property of the conditioned soil of earth pressure balance(EPB) is analyzed.The DEM contact model of the conditioned soil is proposed,on the basis of which the slump test of the conditioned soil is simulated by DEM.The standard slump test is improved in the laboratory.The vertical displacement of the marked particles in the simulation accords with the laboratory slump test results and the final slumped shape in the simulation reproduces the laboratory result.The comparision results illustrate that the proposed DEM contact model can simulate the flow property of the conditioned soil,which provide the basis for the further pressure analysis in the closet of the EPB shield machine.