【作者】 李瑞芳；

【导师】 陈昌富；

【作者基本信息】 湖南大学 ， 土木工程， 2016， 硕士

【摘要】 在现代化建设飞速发展的今天,内陆尤其是西南部地区都修建了大量的基础设施,地震诱发滑坡灾害所造成的生命和财产损失以及对人类社会的冲击也将日益严重。若能计算出地震荷载作用下边坡产生的位移,则可在一定程度上对边坡灾害进行预估。目前,尽管国内外众多学者在对地震滑坡的变形特性进行预测分析时,都进行了比较深入的研究和探讨,也提出了一系列行之有效的方法,但其计算中均采用竖直条分法,且假定岩土在震动过程中的强度保持不变,这与实际情况不符。因此,本文基于已有的Newmark有限滑动位移理论,采用斜条分法对边坡地震永久位移进行分析研究。以Newmark法计算原理为研究基础,采用理论上不失严密性、但计算又相对较简单的Spencer法,提出了一种适应性更强的岩土边坡地震永久位移计算方法。该方法应用Spencer条间力假定,采用斜条分法,同时考虑岩土体强度随震动次数衰减等因素的影响,基于静力平衡条件求得各个时间点处的临界加速度值,计算出边坡永久位移。探讨了条块倾角等因素对位移的影响。结果表明,该方法计算结果能更好的贴合边坡实际位移,对边坡位移计算提供了一种新的研究思路。针对块体破坏形式的岩质边坡,考虑结构面强度衰减,采用Sarma法条间力计算方法,导得了一种实用的岩质边坡地震位移计算公式,并就地震波的振幅、震动周期等因素对位移的影响进行了分析。该计算方法能更好地适应岩质边坡的复杂情况,计算方法简单易行。考虑土体强度衰减,以有限差分软件FLAC3D为计算工具,建立计算模型,对算例边坡进行数值模拟计算,并将得到的坡脚水平位移与采用本文方法计算的结果进行对比分析,两者吻合良好,进一步验证了本文计算方法的可行性。同时,还就土体参数对永久位移的影响进行了分析。更多还原

【Abstract】 In today’s rapid development of modernization, a lot of infrastructure has been built especially in the southwestern inland regions. Earthquake-induced slope disaster has been cause significant losses in terms of damages to people, property and society. If the slope displacement under seismic loads could be calculated, it will to a certain extent facilitate to prevent the slope disaster. At present, many researchers around the world conducted analysis on the deformation characteristics of the seismic slope, and proposed a number of methods to effectively analyze the slope displacement. These methods are based on general limit equilibrium. Among them, the slope mass isdivided into vertical slices, and thegeotechnical strength in shock processremains the same. However, it is inconsistent with the actual situation. According to existing Newmark’s theory of the finite sliding displacement, several studies were carried out to compute the permanent displacement based on inclined slice method.Basedon Newmark’s theory of seismic permanent displacement and Spencer method, a new method which is suitable for geotechnical slope is proposed to calculate the seismic permanent displacement.An inclined slice method wasusedto adapt to the interface which may be tilted between slices. And the attenuation of the shear strength under seismic vibration on the sliding surface and other influencing factors wereconsideredinthismethod. Under the static equilibrium condition, the critical acceleration values were calculated for each time point and then the permanent displacement of slopes were computed. The results show that this new method is not only more adaptable than the existing calculation methods, but also more accurate in the calculation precision, which provides a new insight into theseismic permanent displacement calculation of slope.Based on Sarma’s method, taking into consideration structural plane intensity attenuation, a simple and feasible seismic displacement calculation method for rock slope was developed. The impacts of different factors, such as the amplitude of the seismic waves, vibrations cycle etc. on the displacement were analyzed. The results show that this method is simple but effective and could applied to compute the displacement for rock slope under complex conditions.Considering soil strength attenuation,numerical simulation was performed to analyze the displacement of slopefor the selected case by using the finite difference software FLAC3 D. The horizontal displacement toe wassimulatedand the effects of soil parameters on the permanent displacement of were analyzed. According to the simulation results, it agrees well with the calculated results which further verify the feasibility of the proposed calculation method.更多还原