双级微型桩群加固软岩高边坡作用机理与计算方法研究

发布时间：2018-04-19 19:15

本文选题：软岩高边坡 + 微型桩群　；参考：《西南交通大学》2017年硕士论文

【摘要】：微型桩群是将数根直径较小、长细比较大的钻孔灌注桩在桩顶连接起来的一种新型轻型抗滑支挡结构,特别是在边坡应急抢险及施工条件有限的情况下更适于工程应用。本文依托四川遂资高速公路路堑软岩高边坡工程,对可适于设计滑坡推力较大边坡或滑坡的双级微型桩群的作用机理与计算分析方法进行研究,主要得到以下结果:(1)在单级微型桩群加固滑坡的作用机理基础上,初步揭示了双级微型桩群加固滑坡的作用机制,给出了考虑后级桩群对其前侧坡体挤压作用的双级微型桩群间滑坡推力计算方法。(2)基于弹性地基梁理论的桩挠曲微分方程,在考虑桩前抗力的情形下,给出了微型桩幂级数法和有限差分法的求解方法。对幂级数法,微型桩采用分段计算,并且考虑截断处的位移、转角、弯矩和剪力的耦合。对有限差分法,全桩采用整体计算。利用Matlab编制计算程序,实现了对微型桩的位移、转角、弯矩和剪力具体计算。(3)以遂资高速公路K12工点路堑软岩高边坡为分析原型,采用通过Flac3D进行数值模拟,计算分析了微型桩的位移、转角、弯矩和剪力并确定了滑坡推力的分布形式和大小。后排桩群滑坡推力接近于矩形分布,前排桩群滑坡推力接近于三角形分布,且确定了桩底条件接近于自由端。(4)依托工程实例,将幂级数法、有限差分法的理论计算结果与数值模拟结果进行了对比分析,表明理论分析与数值模拟方法得到的桩体弯矩、剪力和位移等计算结果整体较为符合,说明了两者具有一定的合理性。本文在双级微型桩群加固滑坡的作用机制与微型桩计算分析方法方面的研究结果,可为实际工程提供指导与参考,具有重要的理论与实际意义。
[Abstract]:The micro-pile group is a new type of lightweight anti-slide retaining structure which connects several bored piles with small diameter and large length and fineness on the top of the pile, especially in the case of slope emergency rescue and limited construction conditions, which is more suitable for engineering application. Based on the cutting soft rock high slope engineering of Sichuan Suizi Expressway, this paper studies the action mechanism and calculation and analysis method of the two-stage micro-pile group suitable for the design of the slope with large landslide thrust or landslide. The main results are as follows: (1) on the basis of the mechanism of single-stage micro-pile group strengthening landslide, the mechanism of two-stage micro-pile group strengthening landslide is preliminarily revealed. In this paper, the calculation method of landslide thrust between two-stage micro-pile groups considering the influence of post-stage pile group on the front slope body is presented. The differential equation of pile deflection based on elastic foundation beam theory is given. When the pile front resistance is considered, The power series method and finite difference method of micro pile are given. For the power series method, the micro-pile is calculated in sections, and the coupling of displacement, rotation angle, bending moment and shear force at the truncation is considered. For the finite difference method, the whole pile is calculated as a whole. By using Matlab program, the displacement, rotation angle, bending moment and shear force of micro pile are calculated. The soft rock slope at K12 point of Suizi expressway is used as the analysis prototype, and the numerical simulation is carried out by Flac3D, which is used to calculate the displacement, rotation angle, bending moment and shear force of micro pile. The displacement, rotation angle, bending moment and shear force of micro-pile are calculated and analyzed, and the distribution form and magnitude of landslide thrust are determined. The thrust of the back pile group is close to the rectangular distribution, the front row pile group is close to the triangular distribution, and the condition of the pile bottom is close to the free end. The theoretical results of finite difference method are compared with the results of numerical simulation. The results of theoretical analysis and numerical simulation show that the calculated results of bending moment, shear force and displacement of pile body are in good agreement with each other. It shows that both of them are reasonable. The research results of this paper on the mechanism of strengthening landslide with two-stage micro-pile group and the calculation and analysis method of micro-pile can provide guidance and reference for practical engineering and have important theoretical and practical significance.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U416.14

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