非线性M-C强度准则下预应力锚索加固边坡时效稳定性分析M-P法  

M-P method for analyzing the long-term stability of slope reinforced by pre-stressed cables under the nonlinear M-C strength criterion

作　　者：邓东平[1] 杨春会 谢志军 DENG Dong-ping;YANG Chun-hui;XIE Zhi-jun(College of Civil Engineering,Central South University,Changsha,Hunan 410075,China;Hunan Road and Bridge Construction Group Co.Ltd.,Changsha,Hunan 410000,China;Hunan Pingyi Expressway Construction and Development Co.Ltd.,Yueyang,Hunan 414517,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]湖南路桥建设集团有限责任公司,湖南长沙410000 [3]湖南省平益高速公路建设开发有限公司,湖南岳阳414517

出　　处：《岩土力学》2024年第4期1051-1066,共16页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52278380);湖南省自然科学基金(No.2023JJ30670);湖南省交通运输厅科技项目(No.202008)。

摘　　要：拓展传统极限平衡方法在复杂条件下边坡稳定性分析中的适用性一直是岩土工程界的研究热点。众所周知,边坡岩土体剪切失效一般服从于非线性强度准则,而传统极限平衡方法仅适用于线性强度准则下边坡稳定性分析。此外,预应力锚索作为一种主动防护措施,可极大地即时提高边坡稳定性而被广泛应用于中、大型边坡工程加固。然而,在应力松弛、蠕变效应以及腐蚀环境影响下预应力锚索加固边坡稳定性时效特征往往被忽视。由此,基于Morgenstern-Price(M-P)法,嵌入非线性Mohr-Coulomb(M-C)强度准则,并融入应力松弛与蠕变效应下锚索预应力损失模型以及腐蚀环境下锚索性能劣化模型,从而,建立非线性强度准则下预应力锚索加固边坡安全系数时程表达式。进一步,为了解决非线性强度准则下隐式嵌套公式难以求解的问题,归零化条间法向力初始值,并应用迭代循环求解策略,在引入循环终止允许误差判别条件后,可实现边坡稳定性理论真实结果的逼近求解。经过后续算例对比分析,验证了所提方法的可行性和合理性,与此同时,还研究了不同预应力损失速率和不同锈蚀环境下预应力锚索加固边坡稳定性的时效变化规律。Expanding the applicability of traditional limit equilibrium(LE)methods in slope stability analysis under complex conditions has been a research hotspot in geotechnical engineering field.It is recognized that the shear failure of geotechnical body of slope is typically governed by nonlinear strength criteria,while the traditional LE method is only applicable to the slope stability analysis under the linear strength criterion.Pre-stressed anchors,as an active protection measure,are widely used in the reinforcement of medium and large-scale slope projects because they can greatly and instantly improve the stability of slopes.However,the long-term stability characteristics of slope reinforced by the pre-stressed cables,including stress relaxation,creep,and the effects of corrosion,are often overlooked.To address these issues,an approach based on the Morgenstern-Price(M-P)has been developed.This method incorporates the nonlinear Mohr-Coulomb(M-C)criterion and integrates the pre-stress loss model of the cables under stress relaxation and creep effects,as well as the performance deterioration model of the cables under the influence of corrosion.In order to tackle the challenge of solving implicit nested formulas under the nonlinear strength criterion,the initial value of the inter-slice normal force is set to zero,and an iterative loop calculation strategy is applied.Subsequently,the approximation of the real theoretical results of slope stability can be realized by introducing the criterion of the allowable error of loop termination.Through comparison and analysis of various examples,the feasibility and rationality of this method have been verified.Furthermore,the variation patterns of long-term stability of slope reinforced by the pre-stressed cables under different pre-stressed loss rates and different corrosion environments are also studied.

关 键 词：边坡 极限平衡M-P法 非线性M-C强度准则 预应力锚索加固 时效稳定性 

分 类 号：TU452[建筑科学—岩土工程]