堤(坝)基层状粗粒土发生渗透变形的颗粒运移规律  

Particle Migration Law of Seepage Deformation of Dam Foundation with Layered Overburden

作　　者：黄海均 严新军[1] 毛海涛 王正成[3] HUANG Hai-jun;YAN Xin-jun;MAO Hai-tao;WANG Zheng-cheng(School of Water Conservancy and Civil Engineering, Xinjiang Agricultural University, Urumqi 830052, China;Water Conservancy and Hydropower School, Hebei Engineering University, Handan 056002, China;College of Civil Engineering, Chongqing Three Gorges University, Wanzhou 404100, China)

机构地区：[1]新疆农业大学水利与土木工程学院,乌鲁木齐830052 [2]河北工程大学水利水电学院,邯郸056002 [3]重庆三峡学院土木工程学院,万州404100

出　　处：《科学技术与工程》2020年第16期6620-6627,共8页Science Technology and Engineering

基　　金：国家自然科学基金(51309262);重庆市科委基础与前沿研究计划项目(cstc2018jcyjAX0673);重庆市教委2011协同创新子课题(061500911)。

摘　　要：堤(坝)基常出现强弱互层的土层结构,具有代表性的主要由强透水砂砾石层、弱透水细砂层和强透水砂砾石层组成,渗透时各土层微观的颗粒运移规律对于揭示堤(坝)基渗透变形和破坏机理至关重要。采用三维颗粒流程序并结合“反演模拟法”,准确对颗粒细观参数进行了标定,有效的模拟了该多层堤(坝)基渗透变形的发展过程,获得了堤(坝)基渗透变形过程中的颗粒运移特点及颗粒流失情况。结果表明:渗透破坏主要发生在上部砂砾石层中,随着渗透破坏的持续发生,逐渐影响下部土层,该层中细颗粒在粗颗粒孔隙间移动而后逐渐流失,属于典型的管涌破坏。中间细砂层在上部砂砾石层管涌破坏后,其颗粒最先在管涌口正下方Z4区发生流失,其余区域颗粒流失相对较晚,且颗粒流失量均随着计算时间步的增加而增加,导致细砂层出现小范围的变形。随着计算时间的增加,上部砂砾石层的下沉量是逐渐增加的,当上部砂砾石层细颗粒流失达到一定程度,堤(坝)基发生破坏,将对上部建筑物产生重大危害。为从微观角度认识多层堤(坝)基流渗透破坏提供了一定参考。The foundation of dike(dam)often presents the soil layer structure with strong and weak interaction,which is mainly composed of strong permeable sand gravel layer,weak permeable fine sand layer and strong permeable sand gravel layer.The microscopic particle migration law of each soil layer during seepage is very important to reveal the seepage deformation and failure mechanism of dike(dam)foundation.Using the three-dimensional particle flow sequence and the inversion simulation method,the Micro-Parameters of the particles were calibrated accurately,and the seepage deformation process of the multi-layer embankment(dam)foundation was simulated effectively.The particle migration characteristics and particle loss during the seepage deformation process of the embankment(dam)foundation were obtained.The results show that the seepage damage mainly occurs in the upper gravel layer.With the continuous occurrence of seepage damage,the lower soil layer is gradually affected.The fine particles in the layer move between the coarse grain pores and then gradually lose,which is a typical piping failure.After the piping failure of the upper sand-gravel layer,the particles of the middle fine sand layer first lost in Z4 area just below the piping mouth,while the particles of the other areas lost relatively late,and the amount of particle loss increased with the increase of calculation time,resulting in small-scale deformation of the fine sand layer.With the increase of calculating time,the subsidence of the upper gravel layer is gradually increasing.When the loss of fine grains in the upper gravel layer reaches a certain extent,the foundation of the dyke(dam)will be damaged,which will cause great harm to the upper buildings.A reference was provided for understanding the seepage failure of multi-layer embankment(dam)foundation flow from a micro-perspective.

关 键 词：多层结构 颗粒流 渗透变形 管涌 

分 类 号：TV16[水利工程]