基于修正统一硬化模型的超固结非饱和红黏土边坡稳定分析  

Stability analysis of overconsolidated unsaturated red clay slope based on modified UH model

作　　者：柳伟 徐长节[1] 杜昊东[3] 朱怀龙 王长虹 LIU Wei;XU Chang-jie;DU Hao-dong;ZHU Huai-long;WANG Chang-hong(State Key Laboratory of Performance Monitoring Protecting of Rail Transit Infrastructure,East China Jiaotong University,Nanchang,Jiangxi 330013,China;Department of Architectural Engineering,Jiangxi Vocational and Technical College of Communications,Nanchang,Jiangxi 330013,China;School of Mechanics and Engineering Science,Shanghai University,Shanghai 200444,China)

机构地区：[1]华东交通大学轨道交通基础设施性能监测与保障国家重点实验室,江西南昌330013 [2]江西交通职业技术学院建筑工程学院,江西南昌330013 [3]上海大学力学与工程科学学院,上海200444

出　　处：《岩土力学》2024年第4期1233-1241,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金重点项目(No.52238009);国家自然科学基金高铁联合基金(No.U1934208);江西交通运输厅科技项目(No.2021H0037)。

摘　　要：在降雨和水位升降的联合作用下,库岸边坡易发生滑塌现象。采用理想弹塑性Mohr-Coulomb准则,在干湿循环作用下,分析库岸边坡的稳定性,难以反映边坡土的超固结消散等复杂力学特性。以江西省新干航电枢纽库岸边坡为背景,针对弱超固结非饱和红黏土,开展非饱和直剪试验,采用反正切函数,描述吸力应力与基质吸力的数学物理关系,提出红黏土的超固结非饱和统一硬化(unified hardening,UH)模型。然后,在UH模型的基础上,采用C++语言,开发FLAC3D的应用程序;利用GeoStudio软件的SEEP/W模块,计算降雨入渗的非饱和渗流场;编写接口程序,导入FLAC3D,开展库岸边坡的稳定性计算。库岸边坡的水平位移明显大于经典的非饱和理想弹塑性模型计算结果,结果表明,修正UH模型能够合理地预测超固结非饱和红黏土库岸边坡的稳定性,为同类库岸边坡工程稳定性分析提供了参考。Under the combined effect of rainfall and water level fluctuation,the slope of the reservoir bank is prone to collapse.Ideal elastic-plastic Mohr-Coulomb criterion is used to analyze the stability of reservoir slope,which is difficult to characterize the complex mechanical characteristics of slope soils,such as over consolidation dissipation under wet-dry cycles.It is difficult to analyze the stability of bank slopes under the action of dry and wet cycles to reflect the complex mechanical properties such as overconsolidation and dissipation of slope soils.In this study,focusing on weakly overconsolidated unsaturated red clay at the reservoir bank slope of the Xingan shipping-hydropower junction project in Jiangxi Province,unsaturated direct shear tests were conducted and an overconsolidated unified hardening(UH)model for red clay was constructed.The UH model incorporates the mathematical-physical relationship between suction stress and matric suction using the arctangent function.Subsequently,based on the UH model,an application program of FLAC3D was developed in C++.The SEEP/W module of GeoStudio software was employed to compute the unsaturated seepage field during the rainfall infiltration,and an interface program was created to import FLAC3D data for stability calculations of the reservoir slope.Comparisons between the horizontal displacements obtained from the improved UH model and the classical unsaturated elastic-plastic model revealed significantly larger displacements in the former,suggesting that the improved UH model can provide reasonable predictions of the overconsolidated unsaturated red clay for reservoir slope stability.This research offers valuable insights for similar projects involving analyses of reservoir bank slope.

关 键 词：红黏土 统一硬化模型 吸力应力 超固结 边坡稳定分析 

分 类 号：TU446[建筑科学—岩土工程]