《Journal of Geotechnical and Geoenvironmental Engineering》杂志刊登“复杂应力状态下内侵蚀的临界水力梯度"

作者：D. S. Chang, S. M. ASCE ；L. M. Zhang,；F. ASCE
刊物：《Journal of Geotechnical and Geoenvironmental Engineering》，138卷第7期，680-689页
关键词：溃坝；大坝安全；水力梯度；微结构；渗流；土壤侵蚀
摘要：内侵蚀是指渗流条件下粗土颗粒团里中的细粒土被选择性侵蚀，并影响土体的水力和机械力学性质。本研究通过室内试验在各向等压、三轴排水压缩、三轴伸长应力等复杂应力路径下进行了大量的内侵蚀试验。这些试验的目的是为了研究内侵蚀的初始变化和发展过程，并对应力状态对临界水力梯度的影响进行研究。相应的三个临界梯度被定义为初始梯度、骨架变形梯度和破坏水力梯度。这三个临界梯度分别对应于侵蚀开始时的细粒土充填大孔隙、有强力胶结的粗颗粒体和土体破坏状态。在压应力条件下初始梯度开始随着剪应力比的增大而增大，随后随着应力条件接近破坏而降低。通过各向等压内侵蚀实验得到了在相同的孔隙率下最大的初始梯度和骨架变形梯度。

Critical Hydraulic Gradients of Internal Erosion under Complex Stress States

Authors:D. S. Chang, S. M. ASCE ；L. M. Zhang,；F. ASCE
Journal:《Journal of Geotechnical and Geoenvironmental Engineering》 Volume 138, Number 8,910-921
Key words:Dam failures; Dam safety; Hydraulic gradients; Microstructures; Seepage; Soil erosion
Abstract: Internal erosion involves selective loss of fine particles within the matrix of coarse soil particles under seepage flow, which affects the hydraulic and mechanical behavior of the soil. In this research, extensive laboratory internal erosion tests were conducted under complex stress states following three stress paths: isotropic, drained triaxial compression and triaxial extension stress paths. These tests were designed to investigate the initiation and development of internal erosion and the effect of stress state on critical hydraulic gradients. The entire erosion process can be divided into four phases: stable, initiation, development, and failure. Accordingly, three critical gradients termed as initiation, skeleton-deformation, and failure hydraulic gradients can be defined. These critical gradients correspond to the onset of erosion of the fine particles filling the large pores of the skeleton, the buckling of the strong force chains formed by the coarse particles, and the soil failure, respectively. The initiation gradient under compression stress conditions generally increases with the shear stress ratio first and then decreases when the stress conditions approach failure. The tests under isotropic stress conditions show the largest initiation and skeleton-deformation gradients at the same porosity.

原文链接：http://dx.doi.org/10.1061/(ASCE)GT.1943-5606.0000871
翻译：王丽娟；审核：安鹏