黄土高原地震次生滑坡灾害发生机理及评估方法研究

项目名称： 黄土高原地震次生滑坡灾害发生机理及评估方法研究

项目编号： No.51278397

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 建筑科学

项目作者： 苏立君

作者单位： 西安建筑科技大学

项目金额： 80万元

中文摘要： 地震扰动会对黄土结构造成损伤，导致震后在降水、灌溉和冻融循环等因素的影响下会引发滑坡灾害，然而目前对该类滑坡的机理认识尚不清楚。本项目通过开展原状黄土和经过振动台模拟地震作用扰动的黄土试样的非饱和三轴试验和冻融循环试验，建立黄土强度和变形指标及应力应变关系特征与地震参数之间的定量关系；提出可以描述地震荷载扰动损伤后非饱和黄土力学特性的弹塑性本构模型，建立地震荷载扰动黄土力学参数与冻融循环参数之间的关系式，并将两者结合起来建立地震损伤黄土的水-热-力-变形耦合关系式；在此基础上通过理论和数值分析揭示震后黄土边坡在水分场和温度场变化作用下而产生滑坡灾害的力学机理，确定滑坡发生时的临界条件，并进一步利用数值模型分析其致灾距离和致灾面积及沿程破坏力的大小，形成对该类滑坡的危险性及破坏力的定量评估方法。研究成果有助于更加科学合理地评价地震次生黄土滑坡灾害，为该类滑坡的防治及监测预警提供理论支持。

中文关键词： 非饱和三轴试验；次生滑坡；黄土损伤；冻融循环；

英文摘要： Earthquake will cause damage to the micro-structure of loess, which will lead to landslide under the influence of rainfall, irrigation and repeated freeze-thaw cycles. However, the mechanism of this type of landslide is still not clear. In this project, unsaturated triaxial tests and freezing-thawing tests will be carried out on both undisturbed loess samples and samples disturbed by earthquake loading simulated by a shaking table. Based on the test results, relationship between the strength and deformation characteristics and earthquake parameters will be determined. A elasto-plastic constitutive model that can simulate the mechanical properties of earthquake-damaged unsaturated loess will be established. Quantitative relathionship between mechanical parameters of earthquake-disturbed loess and freezing-thawing parameters will be determined. This relationship will be combined with the constitutive model to establish a freezing-thawing degradation formulation of earthquake-damaged loess. Based on this, the mechanical mechanism of landslide caused by variation of moisture distribution and effects of freeze-thaw cycles follwing an earthquake will be analyzed both analytically and numerically. The critical conditions of the landslide will be determined during the analysis. Further analysis will be carried out using

英文关键词： Unsaturated triaxial test；Secondary landslide；Loess damage；freezing and thawing cycle；