内部侵蚀砂土漏水漏砂试验及离散元数值模拟

Water and Sand Leakage Test and DEM Numerical Simulation of Internal Eroded Sand

砂土内部矿物成分的溶解、降解或内部侵蚀会造成土壤颗粒的损失,改变砂土土壤的微观结构,从而影响砂土的稳定性以及土体的强度和刚度。因此,为了研究不同内部侵蚀程度对引发漏水漏砂灾害的影响,通过引入一定数量的可溶解颗粒(盐)来营造内部侵蚀的情况,在水的渗透作用下,模拟了砂土内部侵蚀后漏水漏砂灾害,并通过三维离散元软件对试验过程进行模拟分析。结果表明,随着内部侵蚀程度从0%增加至30%,砂土沉降最大值从3.6 cm上升至6.6 cm,成拱时间从220 s缩减至140 s,内部侵蚀程度越大,颗粒接触力链越稀疏,导致土层表面塌陷沉降区越陡、越宽,天然滤层通道更深、更宽,砂土损失量越多。研究结果可为内部侵蚀砂土漏水漏砂灾害发生机理提供重要依据。

Dissolution,degradation or internal erosion of mineral components in sandy soils may cause loss of soil particles and change the micro-structure of sandy soils,thus affecting the stability of sandy soils as well as the strength and stiffness of soils.As a result,to study the impact of different internal erosion degree on water and sand leakage disaster,a certain number of erodible particles(salts)are introduced to create internal erosion.Under the influence of water penetration,water and sand leakage disaster after internal erosion of sand is simulated,and the test process is simulated and analyzed by PFC3D.The results show that the sand layers with different internal erosion degree have different shapes after test.The results show that with the increase of internal erosion degree from 0%to 30%,the maximum value of sand settlement increases from 3.6 cm to 6.6 cm,and the arching time decreases from 220 s to 140 s.The larger the internal erosion degree is,the steeper and wider the settlement area of soil surface collapse is,the deeper and wider the natural filter channel is,and the more sand loss is.The research results provide important basis for the occurrence mechanism of water and sand leakage disaster in internal eroded sand.