基于双参数折减的岸坡稳定性分析方法优化研究

发布时间：2018-07-18 21:22

【摘要】：本文针对传统强度折减法单一不合理折减方式以及FLAC3D软件在非饱和渗流分析上存在局限性两个方面所存在的不足进行优化,通过考虑衰减次序间隔的双参数强度折减法和自编孔压场转换程序(seep/w to flac3d)对某滑坡案例进行计算分析,得到了库岸边坡在库水位作用下的渗流场和稳定性变化规律(考虑库水位变化速率影响),为今后涉水边坡的分析、评价和防治提供了一定借鉴,同时也对FLAC3D软件在非饱和渗流分析方面的开发应用做了进一步的探索。本文研究主要取得如下成果:(1)基于理论分析及前人研究成果推导了考虑c、?衰减次序间隔的双参数强度折减解析公式,该式更加符合边坡岩土体实际的破坏机制,为更加准确的评价边坡稳定性问题提供了参考。残余强度的确定始终具有一定的不确定性,本文得到的衰减次序间隔系数a也对解释残余粘聚力和残余内摩擦角的取值及弹性评价边坡稳定性提供了理论依据。(2)本文通过二维渗流计算软件GeoStudio对某滑坡案例进行了分析研究,得到了库水位升降作用下岸坡在不同渗流时刻的渗流场和稳定性变化规律。计算结果表明:库水位上升阶段,边坡稳定性安全系数先降低后升高,并且在安全系数最小时对应存在最危险水位高度;而在库水位下降阶段,边坡安全系数则整体呈现逐渐减小的变化趋势;探讨了库水位升降速率的不同对岸坡稳定性的影响规律,计算结果表明:库水位上升期间,库水上升速率增加或减小时,岸坡稳定性安全系数分别增大和减小;库水位下降期间,库水下降速率增加或减小时,岸坡稳定性安全系数分别减小和增大。(3)本文通过对GeoStudio和FLAC3D两种软件计算模式和理论的研究,基于fish参数化语言,编制了孔压场转换程序(seep/w to flac3d),此程序采用了邻域插值和节点遍历的运行模式,成功实现了同一边坡渗流场导入再分析的问题,为本文思路的验证提供了依据。(4)通过FLAC3D对考虑双参数折减和非饱和渗流影响的某滑坡案例的稳定性进行了计算分析,得到的变形规律与GeoStudio(slope/w)中采用Morgenstern-Price方法所得结果相同,并讨论了库水变动速率的不同对岸坡稳定性的影响,初步建立了一种分析涉水岸坡稳定性的评价方法,初步解决了FLAC3D在非饱和渗流问题上的局限性。
[Abstract]:In this paper, the shortcomings of single unreasonable reduction method of traditional strength reduction method and limitation of FLAC3D software in unsaturated seepage analysis are optimized. A landslide case is calculated and analyzed by using a two-parameter strength reduction method and a self-compiled seep/w to flac3d program, which takes into account the attenuation sequence interval. The seepage field and stability change law of bank slope under the action of reservoir water level are obtained, which can be used for reference for the analysis, evaluation and prevention of the wading slope in the future. At the same time, the development and application of FLAC3D software in unsaturated seepage analysis are further explored. The main achievements of this paper are as follows: (1) based on the theoretical analysis and previous research results, the author deduces the consideration of cu? The analytical formula of two-parameter strength reduction of attenuation sequence interval is more in line with the actual failure mechanism of slope rock and soil and provides a reference for more accurate evaluation of slope stability. The determination of residual strength is always uncertain. The attenuation order interval coefficient a obtained in this paper also provides a theoretical basis for explaining the values of residual cohesion and residual angle of internal friction and evaluating the slope stability with elasticity. (2) in this paper, a landslide case is evaluated by the two-dimensional seepage calculation software GeoStudio. Have carried on the analysis research, The seepage field and stability of bank slope at different seepage time are obtained under the action of reservoir water level rise and fall. The calculation results show that the slope stability safety factor decreases first and then increases at the stage of water level rise, and the most dangerous water level exists when the safety factor is minimum, while at the stage of reservoir water level decreasing, On the other hand, the slope safety factor is gradually decreasing, and the influence of the rise and fall rate of reservoir water level on the slope stability is discussed. The calculation results show that the rising rate of reservoir water level increases or decreases during the period of water level rise. The safety factor of bank slope stability increases and decreases respectively, and during the period of reservoir water level decline, the decreasing rate of reservoir water level increases or decreases. The slope stability safety factor is reduced and increased respectively. (3) through the research of GeoStudio and FLAC3D software calculation mode and theory, based on fish parameterized language, A seep/w to flac3d program is developed, which adopts the operation mode of neighborhood interpolation and node traversal, and successfully realizes the problem of introducing and reanalyzing the seepage field of the same slope. (4) the stability of a landslide case considering the effects of two-parameter reduction and unsaturated seepage is calculated and analyzed by FLAC3D. The results obtained are the same as those obtained by Morgenstern-Price method in GeoStudio (slope/w). The influence of the variation rate of reservoir water on the stability of bank slope is discussed. An evaluation method is established to analyze the stability of bank slope, and the limitation of FLAC3D in unsaturated seepage is solved.
【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU43

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