降雨对广西含泥质夹层碎屑岩边坡的稳定性影响研究

发布时间：2018-03-09 22:46

本文选题：碎屑岩　切入点：泥质夹层　出处：《广西大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文以2014年广西壮族自治区国土资源厅“广西碎屑岩地区地质灾害防治研究”项目为依托,在收集整理第一手资料的基础上采用统计分析、数值模拟及理论分析相结合的方法,研究广西碎屑岩地区滑坡灾害的分布规律、发育特征及碎屑岩区滑坡与降雨的关系,分析降雨对碎屑岩类边坡稳定性的影响。主要研究内容包括：1、统计分析2005年～2013年广西碎屑岩分布区地质灾害资料。分析结果表明滑坡是广西碎屑岩地区分布最广泛的地质灾害,以小型、浅层滑坡为主,降雨是最主要的诱发因素之一。2、研究广西碎屑岩分布区滑坡灾害与降雨的关系。研究结果表明,滑坡的发生与降雨前1-4天的降雨过程有较好的相关性,其中与滑坡前两天的降雨相关性最好；降雨型滑坡主要发生在暴雨期间；滑坡的发生时间滞后于降雨峰值出现的时间,并随着降雨强度的增加滞后时间有缩短的趋势。3、统计分析大量历史滑坡的勘察资料,分析广西碎屑岩区滑坡的地层岩性和各层土体的物理力学特性。分析结果表明,碎屑岩地区的滑坡主要发生在含有泥质夹层的边坡中,在降雨条件下边坡多沿泥质夹层发生破坏；泥质夹层强度较低,遇水易发生崩解软化,强度大幅步降低,为滑坡的形成提供了潜在滑移面。4、根据广西碎屑岩地区边坡特点建立碎屑岩与泥质带互层的边坡模型,利用Geo-studio数值分析软件中的SEEP/W和SLOPE/W模块模拟分析含有泥质夹层的边坡中泥质夹层对边坡内渗流场和边坡稳定性的影响。模拟结果表明,当降雨强度、降雨时间达到一定程度时,泥质夹层表面将出现暂时的积水区,降雨强度越大、降雨时间越长,积水越明显；泥质夹层被积水浸泡饱和度大幅增加、孔隙水压力升高、基质吸力降低、土体抗剪强度降低形成一层软弱带,边坡的稳定性降低；在相同的降雨时间里,坡度越小,降雨对坡体内部的土体的孔隙水压力影响越大,对边坡的稳定性影响越大；降雨诱发的滑坡潜在滑动面主要分布在相对隔水层表面或软硬土层的接触面。
[Abstract]:In 2014, based on the project of "study on the prevention and control of geological hazards in the clastic rock region of Guangxi" of the Department of Land and Resources of Guangxi Zhuang Autonomous region, this paper adopts the methods of combining statistical analysis, numerical simulation and theoretical analysis on the basis of collecting and arranging first-hand data. The distribution law, development characteristics and relationship between landslide and rainfall in clastic rock area of Guangxi are studied. This paper analyzes the influence of rainfall on the stability of clastic rock slope. The main research contents include: 1, statistical analysis of geological hazard data of clastic rock distribution area in Guangxi from 2005 to 2013. The results show that landslide is the most widely distributed geological hazard in the clastic rock area of Guangxi. The relationship between landslide disaster and rainfall in the distribution area of clastic rocks in Guangxi is studied. The results show that the occurrence of landslide has a good correlation with the rainfall process 1-4 days before rainfall. The correlation between landslide and rainfall two days before the landslide is the best; the rainfall type landslide mainly occurs during the rainstorm; the time of landslide occurrence lags behind the time of peak rainfall. With the increase of rainfall intensity, the lag time has a tendency of shortening. 3. The investigation data of a large number of historical landslides are statistically analyzed, and the stratigraphic lithology and physical and mechanical properties of each layer of soil in the clastic rock area of Guangxi are analyzed. The landslide in the clastic rock area mainly occurs in the slope with muddy intercalation. Under the condition of rainfall, the slope is destroyed along the muddy intercalation, the strength of the muddy intercalation is low, it is easy to collapse and soften when the water is encountered, and the strength of the muddy intercalation decreases greatly. The potential slip surface. 4 is provided for the formation of the landslide. According to the characteristics of the clastic rock slope in Guangxi, the slope model of interbedded clastic rock and muddy zone is established. The influence of muddy interlayer on the seepage field and slope stability in a slope with muddy intercalation is simulated by using SEEP/W and SLOPE/W modules in Geo-studio software. The simulation results show that when rainfall intensity and rainfall time reach a certain degree, The surface of the muddy intercalation will have temporary hydrological zone, the greater the rainfall intensity, the longer the rainfall time, the more obvious the water is, the higher the saturation of soaking by water, the higher the pore water pressure, the lower the matrix suction. In the same rainfall time, the smaller the slope degree, the greater the influence of rainfall on the pore water pressure of the soil, and the greater the influence on the slope stability. The potential sliding surface of the landslide induced by rainfall is mainly distributed on the surface of relative water barrier or the interface of soft and hard soil.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU457

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