边坡变形预测与位移速率预警阈值方法研究

发布时间：2018-05-15 19:23

本文选题：变形预测 + 时序分析法　；参考：《西南交通大学》2015年硕士论文

【摘要】：边坡的变形预测与预警研究一直以来都是岩土工程领域的重要课题。边坡的准确预测和及时预警不仅有利于边坡的整体安全,也有利于周边生命财产的安全。本文从预测与预警两个角度着手,结合数学理论与数值模拟手段,进行边坡的变形预测模型和分级预警阈值的确定的研究工作,主要研究内容与成果如下：1.基于时序分析法,以边坡变形监测数据为位移时间序列,分解趋势项位移与季节项位移,引入GM灰色模型与ARMA模型,提出并建立了边坡预测的位移分离模型。利用所建模型对大水田边坡数据作位移预测分析,并与常规模型进行预测精度的对比,结果表明位移分离模型具有更好的预测效果。2.基于工程类比法,选取了影响滑坡相似程度的9个因子(边坡角、断层节理发育程度、滑动破坏模式、滑动面深度、岩体结构、岩体基本质量、降雨量、地下水及开挖爆破)。对各因子进行了分级量化,并利用层次分析法确定其影响权重。由此提出确定边坡相似程度的计算方法。3.收集了24个典型滑坡及其相关资料,主要涉及边坡的地质构造条件、水文气候条件及破坏前的位移变化情况等。根据滑坡三阶段规律,确定把边坡进入中加速阶段、初加速阶段及安全储备系数为1.25的等速变形后期时的三个变形速率作为滑坡位移速率预警阈值。4.对布沼坝露天矿西帮边坡运用基于工程类比法的预警阈值方法进行分析,找到与其最相似的已滑边坡——抚顺西露天矿西帮人卷车滑坡,给出了边坡三个级别的位移速率预警值2.62mm/d、3.27mm/d及12.13mm/d。利用Midas/GTS软件模拟西帮边坡的分步开挖,计算得到坡体进入初加速阶段与中加速阶段时的累计位移分别为130mm与400mmm,与基于工程类比法的位移速率预警值对应的累计位移值150mm与470mm基本吻合,说明该位移速率预警阈值的确定方法具有一定现实意义。
[Abstract]:The study of slope deformation prediction and early warning has always been an important subject in geotechnical engineering field. Accurate prediction and early warning of slope are not only conducive to the overall safety of slope, but also conducive to the safety of life and property around the slope. From the angles of prediction and early warning, combining mathematical theory and numerical simulation, this paper studies the prediction model of slope deformation and the determination of the threshold of graded warning. The main research contents and results are as follows: 1. Based on the time series analysis, the displacement separation model of slope prediction is proposed and established by introducing GM grey model and ARMA model, taking slope deformation monitoring data as displacement time series and decomposing trend term displacement and season term displacement. The model is used to predict and analyze the displacement of large paddy slope data, and the prediction accuracy is compared with the conventional model. The results show that the displacement separation model has better prediction effect. Based on the engineering analogy, nine factors (slope angle, fault joint development, sliding failure mode, sliding surface depth, rock mass structure, basic rock mass quality, rainfall, groundwater and excavation blasting are selected. The influence weight of each factor is determined by analytic hierarchy process (AHP). Therefore, a calculation method for determining the similarity degree of slope is put forward. In this paper, 24 typical landslides and their related data are collected, which mainly involve the geological and structural conditions of the slope, hydro-climatic conditions and displacement changes before failure. According to the law of three stages of landslide, the three deformation rates of the slope in the middle acceleration stage, the initial acceleration stage and the late stage of isokinetic deformation with safe reserve coefficient 1.25 are determined as the early warning threshold of landslide displacement rate .4. Based on the analysis of the early warning threshold method based on the engineering analogy method, the slope of west side of Buzhuaba opencast mine is analyzed, and the most similar landslide is found in the west side slope of Fushun West Open-pit Mine. The displacement-rate warning values of 2.62 mm / d 3.27 mm / d and 12.13 mm / d are given for the three levels of slope displacement. The Midas/GTS software is used to simulate the step excavation of the west slope. The accumulative displacement of slope at the initial acceleration stage and the middle acceleration stage is calculated to be 130mm and 400mmm, respectively, which is basically consistent with the cumulative displacement value 150mm and 470mm corresponding to the early warning value of displacement rate based on the engineering analogy method. It shows that the method of determining the threshold of displacement rate warning is of certain practical significance.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU433

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