【作者】 张卫中；

【导师】 尹光志；

【作者基本信息】 重庆大学 ， 安全技术及工程， 2007， 博士

【摘要】 随着国家经济发展,特别是西部大开发的开展,公路建设逐年增长,而且不断向山区延伸,因为地形、地貌等条件的约束,不可避免地会形成大量的边坡工程,甚至出现高陡人工边坡,以高等级公路的建设最为严重。在现有的公路线路中,不少线段屡有滑坡等地质灾害发生,造成车毁人亡,运输中断,损失惨重。所以进行路堑边坡稳定性研究意义非常重要。本文以渝黔高速公路向家坡滑坡为工程背景,系统研究了路堑边坡稳定性评价、失稳机理、监测及预报,以及正在运营中的路堑边坡动态优化综合治理问题。论文所取得的主要成果如下:①利用MTS岩石材料试验机对向家坡路堑边坡岩石在不同围压和不同含水量的变形、强度特征进行了试验研究,根据有围压的莫尔-库仑强度准则,依据最小二乘法,采用回归分析求解出了向家坡路堑边坡岩石试件的强度参数内摩擦角?和粘聚力C ;根据弹塑性力学理论,以弱风化砂岩为例,提出了能正确反映岩石三轴受力的抛物线-线弹性-Duncan双曲线-塑性软化-残余理想塑性五段式模型。②结合向家坡滑坡工程地质情况以及变形情况,总结了向家坡滑坡特征,深层次分析了该开挖路堑边坡降雨诱发失稳机理,汲取了向家坡滑坡前期治理失败的原因。③考虑降雨对滑坡滑面介质的应变软化和水致弱化性质,提出了三维滑坡力学模型,应用突变理论对其失稳力学机制进行了分析;总结了浅层滑坡坡体位移与降雨量的拟合关系,结合向家坡滑坡工程实例建立了考虑降雨对滑坡滑面介质的应变软化和水致弱化影响下浅层滑坡的尖点突变模型,分析了向家坡滑坡强降雨条件下浅层失稳的破坏机制。④结合向家坡这一路堑边坡的具体地形地貌以及滑坡等情况,设计出以地表监测为主、辅以深部位移监测及地下水监测等多层次综合监测系统,经现场一年多的测试,效果很好。⑤采用指数平滑法和非线性回归分析相结合的方法,建立了滑坡预测的非线性数学模型,并应用于向家坡工程实践;详细分析了滑坡演变的非线性特征,建立了基于时间序列向空间重构混沌方法的滑坡预测模型,并给出基于时间序列向空间重构混沌方法预测滑坡的一般步骤。⑥基于最优传递矩阵改进层次分析法求解权重,建立了基于可拓理论结合改进层次分析法的边坡稳定性综合评价模型,并应用于向家坡稳定性评价。⑦考虑前期治理的支挡工程和土体的共同作用,将其视为桩土复合体,对滑坡体岩体力学参数进行了综合取值;采用反分析法和极限平衡法对边坡在不同工况下的稳定情况进行了计算;根据传递系数法计算了边坡的下滑推力,为边坡的加固处理提供了科学的依据。⑧提出了“基于治理方案优选+优选方案细化结合监测信息反馈”的滑坡综合治理思路;考虑层次分析法存在的问题,详细介绍了模糊层次分析法的基本原理以及数学模型的建立,给出了模糊层次分析法权重以及判断矩阵一致性检验的简单可行方法,提出了基于模糊层次分析法的多目标决策问题的解决方案,并应用于向家坡滑坡治理方案的优选。⑨针对向家坡路堑高边坡的实际情况,确定了临时抢险和长久根治相结合的综合方案,采取以加固方案结合地下以及地表排水等主要治理措施对向家坡路堑滑坡进行了综合治理;同时采用监测信息反馈实现治理方案优化、滑坡治理的动态化施工和治理效果检验。更多还原

【Abstract】 More and more highways mushroom with western development plan proceeding, some of them are cutting through mountainous areas and landslide occur frequently which possibly not only lead to the close of roads but also pose a serious threat to the security of the traffic. In view of that, the investigation into the instability mechanism underlying the landslip and the improvement of the safety of slopes erected at both sides of a highway are of significance.In the thesis, the Xiangjiapo landslide on the expressway of YuQian is taken as an example to evaluate the stability , study the instability mechanism and the establishment of the monitoring system of a road slope, in addition, a dynamical optimization treating system of road slopes is presented. The main results attained are as follow:①Presents the test results of specimens under saturation, air-dried and drying conditions, respectively, on the MTS obtained from Xiangjiapo site to determine the mechanical properties of various rock masses constituting sliding body of Xiangjiapo, an Mohr circle was graphed according to values of the triaxial strain and confining stress, failure theory and strength parameters: c andφwere obtained through analyzing the curve fitting. Finally a constitutive model developed based on test data, which is characterized by an initial parabola, a next linear elasticity, a following Duncan model curve and a strain softening, the last perfect plasticity. In addition, the application of the model is also presented .②Discusses the mechanism of rainfall triggering landslip in connection with the creeping characteristics of Xiangjiapo sliding mass. The failure of previous treatment of the slope mass creeping was analyzed and the stability of the slope by homogenizing the sliding body and the previous reinforcement was evaluated.③Presuming that the slip surface is made up of elasto-brittle medium and strain-softening medium,a three-dimensional cusp model is formulated with simple law of mechanics; The relationship between slope-mass slide displacement and rainfall was analyzed by means of mathematic statistics. Based on the engineering example ,a cusp-catastrophic model of shallow landslide was established by means of nonlinear science catastrophe theory connected by engineering concrete example of xiangjiapo landslide, to reveal the sudden instability and failure mechanism of shallow landslide due to intensive rainfall.④On the basis of geological features of Xiangjiapo cutting excavation slope, this paper presents a comprehensive monitoring scheme including surface and deep movement monitoring as well as underground water monitoring, aiming to forecast possible catastrophe. The field application shows this monitoring system is practicable;⑤A model of exponential smoothing in combination with nonlinear regression is given and the application of the model to Xiangjiapo monitoring data is also presented. The nonlinearity of the mass creeping evolution is discussed by introducing the nonlinear time series techniques, based mainly on the reconstruction of the phase space, and the general nonlinear prediction principals is given.⑥Based on the improvement of AHP by the optimal transfer matrix ,the weights were abtained , and the Extension Theory in combination with improved hierarchy estimate model was set up and applied in xiangjiapo landslide.⑦Evaluated the stability of landslide by means of back analysis method and limit equilibrium method which under the considering gliding mass and prior period anti-slope project as soil-pile complexus ; The slide thrust was attained by transfer coefficient methods, which offered scientific gist for landslide reinforce.⑧The comprehensive control thought“treating scheme optimization+optimization scheme analysis combined monitoring information feedback”had been brought forward in the paper; Firstly the paper pointed out the defects of AHP, the basic theory of FA HP was presented and a mathematical model of fuzzy analytic hierarchy process was built up ,then the building method of fuzzy complementary judgment matrix ,the formula of weight and the consistency check method of judgment matrix were given. Lastly the application in the scheme selection for xiangjiapo landslide treating had proved the validity of this method.⑨According to the characteristic of express way landslide, both temporary protecting and perpetual comprehensive control scheme are made. Furthermore, an optimization and verification of the treatment plan based on the monitoring information feedback is also discussed.更多还原