含多层软弱夹层的顺层边坡渐进失稳判定及局部破坏范围研究

发布时间：2018-11-10 13:11

【摘要】：近年来,随着我国向西部修筑大量的铁路和高速公路,顺层路堑边坡总是不可避免地大量的出现,特别是顺层边坡中含有多层软弱夹层时,开挖后顺层边坡中不同岩层之间的错动变形对软弱夹层产生复杂的应力和应变状态,如何对含有多层软弱夹层的顺层边坡进行稳定性评价和加固则成为边坡工程中的重点,然而目前对该方面的研究成果较少。因此,本文将通过理论分析、数值模拟、数理统计等研究手段和方法对含多层软弱夹层的顺层边坡渐进失稳判定方法及局部破坏范围进行了研究,得到了含多层软弱夹层的顺层边坡渐进失稳、整体失稳、整体稳定的判别方法,提出了含多层软弱夹层的顺层边坡局部破坏范围计算方法及步骤,主要研究内容如下:(1)分析软弱夹层的渐进破坏特性,运用FLAC3D建立含有多层软弱夹层的顺层边坡,分析开挖到软弱夹层出露后顺层边坡的应力以及变形特征,从而提炼出含多层软弱夹层的顺层边坡渐进破坏机理(2)考虑软弱夹层的应变软化特性对顺层边坡稳定性影响,基于塑性极限分析中的上限理论,推导出含多层软弱夹层的顺层边坡发生整体稳定、整体失稳、渐进失稳的判定方法。(3)运用离散元软件UDEC建立含多层软弱夹层的顺层边坡数值模型以及其中的fish功能对软件进行二次开发,实现了顺层边坡破坏过程中软弱夹层参数弱化,再现了含多层软弱夹层的顺层边坡渐进破坏过程,并且将顺层边坡局部破坏范围确定为坡体监测位移的拐点。(4)基于含多层软弱夹层的顺层边坡渐进破坏机理,建立顺层边坡中各参数与局部破坏范围值的关系。运用数理统计分析对各参数与局部破坏范围值进行回归分析,据此得到含单层软弱夹层的顺层边坡局部破坏范围理论计算公式。(5)基于含单层软弱夹层的顺层边坡局部破坏范围理论计算公式,对含多层软弱夹层的顺层边坡破坏形式进行分类,对不同破坏形式建立了含多层软弱夹层的顺层边坡局部破坏范围的计算公式及步骤。
[Abstract]:In recent years, with the construction of a large number of railways and highways to the west of China, it is inevitable that there are a large number of bedding cutting slopes, especially when there are many layers of soft interlayers in the bedding slopes. After excavation, the staggered deformation between different rock layers in the bedding slope produces complex stress and strain state on the soft interlayer. How to evaluate and strengthen the stability of the bedding slope with multi-layer soft intercalation becomes the key point in the slope engineering. However, the current research on this area is less. Therefore, through theoretical analysis, numerical simulation, mathematical statistics and other research means and methods, this paper studies the determination method of progressive instability and local failure range of bedding slope with multi-layer weak intercalation. The method of judging the stability and stability of the bedding slope with multi-layer soft intercalation is obtained, and the calculation method and steps of the local failure range of the bedding slope with multi-layer weak intercalation are presented. The main research contents are as follows: (1) the progressive failure characteristics of weak intercalation are analyzed, and the stress and deformation characteristics of bedding slope with multi-layer weak intercalation are analyzed by using FLAC3D. Therefore, the progressive failure mechanism of bedding slope with multi-layer soft intercalation is abstracted. (2) considering the influence of strain softening characteristics of soft intercalation on the stability of bedding slope, based on the upper limit theory of plastic limit analysis, The overall stability and overall instability of the bedding slope with multi-layer weak intercalation are deduced. (3) the numerical model of bedding slope with multi-layer soft intercalation and its fish function are established by using discrete element software (UDEC). The parameter weakening of soft interlayer is realized in the failure process of bedding slope, and the gradual failure process of bedding slope with multi-layer soft interlayer is reappeared. The local failure range of bedding slope is determined as the inflection point of slope body monitoring displacement. (4) based on the progressive failure mechanism of bedding slope with multiple layers of weak intercalation, the relationship between the parameters of bedding slope and the value of local failure range is established. The regression analysis of each parameter and the value of local failure range is carried out by means of mathematical statistical analysis. Based on the theoretical formula of local failure range of bedding slope with single layer weak intercalation, (5) based on the theoretical formula of local failure range of bedding slope with single layer weak intercalation, The failure forms of bedding slope with multi-layer weak intercalation are classified, and the calculation formulas and steps of local failure range of bedding slope with multi-layer weak intercalation are established for different failure forms.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U416.14;U213.13

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