抗滑桩边坡降雨入渗分析

发布时间：2018-01-13 20:39

本文关键词：抗滑桩边坡降雨入渗分析　出处：《湘潭大学》2014年硕士论文　论文类型：学位论文

【摘要】：边坡稳定研究是岩土、土木工程领域的重要研究课题，正确分析边坡稳定性问题，对加强工程建设的指导、确保人民生命财产的安全，意义十分重大。抗滑桩是边坡失稳防治加固的主要措施之一，它能够有效支挡滑坡推力，增强边坡的稳定性，且具有良好的经济效益。降雨是引起边坡失稳的重要因素之一，雨水下落对边坡表层造成动能冲击，雨水入渗能降低岩土强度参数，减小边坡的抗剪强度。本文将降雨渗流影响和抗滑桩加固边坡稳定的研究现状归纳和概括。阐述了抗滑桩支护边坡技术，介绍了几种常用的支护类型，并列举了抗滑桩支护边坡的优越性。在总结前人研究成果的基础上，将强度折减原理同ABAQUS相结合，考虑流固耦合和接触，建立了抗滑桩边坡入渗数值模型，对边坡的稳定性进行研究分析。主要研究成果如下：（1）用基于强度折减理论ABAQUS的有限元分析模型求出边坡的安全系数，将其与理正计算出来的安全系数（基于传统瑞典条分法和Janbu法）进行对比，发现三者的数值变化非常接近，验证了基于强度折减理论的降雨入渗边坡模型在ABAQUS软件的适用性。（2）通过降雨时长对边坡的影响稳定的分析，发现随着降雨时间的持续，边坡的安全系数出现较为明显的减少。降雨24h后，安全系数下降到1.022，当降雨达到72h后，雨水入渗大大降低了土体的抗剪承载力，随着入渗深度加大，边坡稳定性越趋于危险，安全系数下降较大幅度仅为0.875小于1.0，表明减少降雨时长对边坡稳定有一定的效果。（3）建立抗滑桩边坡入渗有限元模型，对入渗边坡的稳定进行分析。研究表明：1）通过对降雨时长影响分析，，随着持续降雨边坡土体饱和度值开始上升，由于桩的阻碍作用，抗滑桩左侧与右侧有较为明显的阶梯状态；由于抗滑桩作用，在桩体下侧土体开始形成新的平衡体系，新形成的小边坡开始出现新的坡角应力。该坡脚处的应力继续增加，抗滑桩桩侧与桩顶处也有持续增长的应力。2）抗滑桩桩长的增加能有效遏制边坡位移的增加，最大位移随桩长增长有减少的趋势，在桩长的附近出现了位移集中。当桩长超过一定限值，桩长对位移的影响又出现了弱化。3）通过对抗滑桩设桩位置进行分析，发现抗滑桩设置在滑裂面处，能有效阻止土体位移，设在滑裂面中部偏下，贡献最大，其他位置逐渐弱化，偏离滑裂面则贡献微弱。4）对抗滑桩桩体位移和受力进行分析，发现桩身上部发生弯曲变形，桩顶位移最大，其变形模式表现为剪切型。
[Abstract]:Slope stability research is an important research topic in the field of geotechnical and civil engineering. The correct analysis of slope stability can strengthen the guidance of engineering construction and ensure the safety of people's life and property. The anti-slide pile is one of the main measures to prevent and strengthen the slope instability. It can effectively support the landslide thrust and enhance the slope stability. Rainfall is one of the important factors causing slope instability. Rain Water's fall causes kinetic energy impact on the surface of the slope. Rain Water infiltration can reduce the geotechnical strength parameters. In this paper, the influence of rainfall seepage and the stability of slope strengthened by anti-slide pile are summarized and summarized. The technology of anti-slide pile supporting slope is expounded, and several kinds of common supporting types are introduced. On the basis of summarizing the previous research results, the strength reduction principle is combined with ABAQUS to consider fluid-solid coupling and contact. The numerical model of anti-slide pile slope infiltration is established, and the stability of the slope is studied and analyzed. The main research results are as follows: 1) the safety factor of slope is calculated by using the finite element analysis model based on strength reduction theory (ABAQUS). By comparing it with the calculated safety factor (based on the traditional Swedish slice method and Janbu method), it is found that the three values are very close to each other. The applicability of rainfall infiltration slope model based on strength reduction theory in ABAQUS software is verified. 2) through the analysis of the influence of rainfall duration on slope stability, it is found that the safety factor of slope decreases obviously with the duration of rainfall, and after 24 hours of rainfall. The safety factor decreased to 1.022. After 72 hours of rainfall, Rain Water infiltration greatly reduced the shear bearing capacity of soil. With the increase of infiltration depth, slope stability became more and more dangerous. The decrease of safety factor is only 0.875 less than 1.0, which indicates that reducing rainfall duration has certain effect on slope stability. Finally, the finite element model of anti-slide pile slope infiltration is established to analyze the stability of the infiltration slope. The research shows that the value of soil saturation of the slope begins to rise with the continuous rainfall through the analysis of the influence of rainfall duration. Because of the hindrance of the pile, the left and the right side of the anti-slide pile have obvious ladder state. Due to the action of anti-slide pile, a new equilibrium system began to form in the soil of the bottom of the pile, and the new angle stress began to appear in the newly formed small slope, and the stress at the bottom of the slope continued to increase. The increase of pile length can effectively restrain the increase of slope displacement, and the maximum displacement decreases with the increase of pile length. Displacement concentration occurs near the pile length. When the pile length exceeds a certain limit, the influence of pile length on displacement is weakened. 3) by analyzing the position of anti-slide pile, it is found that the anti-slide pile is located on the sliding crack surface. Can effectively prevent the soil displacement, located in the middle of the sliding fracture plane, the largest contribution, the other position gradually weakened, deviated from the sliding surface contribution is weak. 4) the analysis of the displacement and force of the pile body. It is found that bending deformation occurs in the pile body and the top displacement of the pile is the largest, and its deformation mode is shear type.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU473.1

【参考文献】