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管涌对堤防工程的危害极为严重,人类对管涌的认识也逐渐加深。目前,对管涌破坏开始的条件及其破坏后通道贯通的后果了解较多,然而,因其破坏及发展机制的复杂性,对于管涌发生后涌砂及流量的研究并不深入。通过自行设计的室内模型,改变上覆黏土的厚度对3组土性相同的无黏性土试样进行试验。对测压管水头、通道范围、涌砂量和流量等进行对比分析,研究孔隙率、渗透系数以及流量的变化规律,发现涌砂随时间变化满足非线性关系——Boltzmann模型。最后,利用渗透系数与孔隙率以及孔隙率与累计涌砂量的关系,推导并验证了流量随时间变化的理论公式。这对于认识管涌和有效控制管涌发展以及减灾避难有着非常重要的意义。
Piping on the embankment project is extremely serious harm, human understanding of piping is also gradually deepening. However, due to the complexity of its damage and development mechanism, there is not much research on the surge of sand and flux after the occurrence of piping. Through self-designed indoor model, the thickness of overlying clay was changed to test three groups of non-cohesive soil samples with the same soil properties. Comparing and analyzing the head, passage range, grit discharge and flow rate of piezometer, the change rule of porosity, permeability coefficient and flow rate are studied. It is found that the gushing sand changes with time to meet the nonlinear relation - Boltzmann model. Finally, based on the relationship between permeability coefficient, porosity, porosity and accumulated sand production, a theoretical formula for the change of flow with time is derived and verified. This is of great significance for understanding piping and for effectively controlling the development of piping and disaster reduction asylum.