黄土填方边坡物理模拟过程中微结构变形破坏特征

发布时间：2018-03-15 05:28

本文选题：黄土滑坡　切入点：微结构　出处：《科学技术与工程》2017年33期 　论文类型：期刊论文

【摘要】：在黑方台地区,常年发生大量的黄土滑坡,对黄土滑坡破坏特征的研究有利于黄土滑坡的预测预报。通过物理模拟实验再现了这类滑坡的破坏过程,利用电镜扫描并借助图像处理软件分析了坡体破坏过程中的土体微结构变化特征,并结合直剪试验研究了土体强度变化特征。得到了以下结论,破坏前黄土颗粒的孔隙率在20%~22%之间,破坏后的黄土颗粒孔隙率13%左右。破坏后的黄土强度低于破坏前,内聚力C、内摩擦角φ均降低。黄土破坏时,颗粒结构重新排列,颗粒间胶结物肢解分散,是孔隙率降低的主要原因。黄土破坏时颗粒结构的改变导致孔隙水压力突增,与宏观变形破坏特征具有一致性,这说明微结构变形破坏特征具有突发性。
[Abstract]:In Heifangtai area, a large number of loess landslides occur all the year round. The study of the failure characteristics of loess landslides is beneficial to the prediction and prediction of loess landslides. The failure process of such landslides is reproduced by physical simulation experiments. The change characteristics of soil microstructure during slope failure are analyzed by means of scanning electron microscope and image processing software, and the change characteristics of soil strength are studied in combination with direct shear test. The following conclusions are obtained. The porosity of loess particles is between 20% and 22% before failure, and the porosity of loess particles after failure is about 13%. The strength of loess after failure is lower than that before failure, cohesion C and friction angle 蠁 decrease. The dismemberment and dispersion of cement between particles is the main reason for the decrease of porosity. The change of particle structure during the failure of loess results in a sudden increase of pore water pressure, which is consistent with the characteristics of macroscopic deformation and failure. This indicates that the deformation and failure characteristics of microstructures are sudden.
【作者单位】：成都理工大学地质灾害防治与地质环境保护国家重点实验室;
【基金】：四川省国土资源厅科学研究计划(KJ-2015-18) 创新群体科学研究基金(41521002)资助
【分类号】：P642.22;TU444

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