欠稳定斜坡上抗滑桩桩前土体稳定与抗力发挥程度的研究

发布时间：2018-04-22 06:00

本文选题：斜坡 + 抗滑桩　；参考：《西南交通大学》2016年硕士论文

【摘要】：我国西部山区地质条件复杂,地形起伏大,公路、铁路在此地势中建设时难免会形成斜坡高填方路堤。抗滑桩作为一种支护结构凭借其良好的支挡和阻滑性能在工程中被广泛使用。本文采用Plaxis2D有限元软件对边坡稳定分析中采用强度折减法确定安全系数时的三种不同边坡失效判别方法进行了分析,对抗滑桩桩前土体稳定与抗力发挥程度之间的关系进行了研究,最后利用所得的桩前土稳定安全系数与抗力发挥程度随坡度之间的变化关系采用理正软件计算抗滑桩的内力和位移并与Plaxis软件计算结果对比。主要结论如下：(1)三种不同失效判断方式下边坡的稳定安全系数差别不大,计算不收敛时选取的三个控制点水平位移大小基本一致。三点水平位移与折减系数曲线出现明显的拐点,拐点对应的安全系数相同与所选控制点位置和所在土层无关。(2)随着桩前土坡度的增大桩前土稳定性降低,桩前土水平抗力发挥程度和稳定安全系数均在减少。(3)获得了不同强度参数组合下桩前土稳定安全系数与抗力发挥程度随坡度的变化关系。当桩前土地面倾斜时,组合①②桩前土抗力发挥程度和稳定安全系数与坡度之间基本呈线性关系,组合③④⑤当坡度小于30°时随着坡度的增大其抗力发挥程度减小较缓,稳定安全系数减小较快,当坡度大于30°时随着坡度的增大其抗力发挥程度减小较快,稳定安全系数减小较缓。地面水平时,五种组合抗力发挥程度和稳定安全系数均较地面倾斜时大。(4)当Plaixs软件中为双排桩模型时,前排桩的位移和内力两软件计算结果相差在10%-40%之内。当Plaixs软件中为单排桩模型时,理正计算的最大弯矩和锚索拉力与Plaxis计算结果相差在10%以内,最大剪力和水平位移相差分别为34%和31%。单排桩情况下Plaxis软件计算的桩前土稳定安全系数与理正计算时采用的安全系数基本一致。
[Abstract]:The geological conditions in the mountainous areas of western China are complicated and the topography is large. The high slope embankment will inevitably be formed in the construction of highway and railway in this terrain. As a kind of supporting structure, anti-slide pile is widely used in engineering by virtue of its good supporting and anti-slip performance. In this paper, Plaxis2D finite element software is used to analyze three different slope failure discrimination methods when the strength reduction method is used to determine the safety factor in slope stability analysis. The relationship between soil stability and resistance in front of anti-slide pile is studied. Finally, the internal force and displacement of anti-slide pile are calculated by using the relationship between the stability safety factor of pile front soil and the exertion degree of resistance with the slope. The results are compared with those calculated by Plaxis software. The main conclusions are as follows: (1) under the three different failure judgment modes, the stability safety factor of the slope is not different, and the horizontal displacement of the three control points selected when the calculation is not convergent is basically the same. There are obvious inflection points in the curve of horizontal displacement and reduction coefficient of three points, and the safety factor corresponding to the inflection point is the same as the position of the selected control point and the soil layer. 2) with the increase of the soil slope in front of the pile, the stability of the soil in front of the pile decreases. Under different strength parameters, the relationship between the stability safety factor and the exertion degree of soil stability with slope was obtained. When the soil surface in front of the pile is tilted, there is a linear relationship between the soil resistance in front of the composite pile and the stability safety factor and the slope. When the slope is less than 30 掳, the resistance of combination 345 decreases slowly with the increase of the slope. When the slope is larger than 30 掳, the stability safety factor decreases more quickly, and the stability safety factor decreases slowly with the increase of slope. When the Plaixs software is a double-row pile model, the difference between the displacement and internal force of the front pile is within 10% -40%. When the single row pile model is used in Plaixs software, the difference between the maximum bending moment and cable tension calculated with Plaxis is less than 10%, and the difference between maximum shear force and horizontal displacement is 34% and 31%, respectively. In the case of single row pile, the safety factor of soil stability calculated by Plaxis software is basically the same as that used in rational calculation.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U416.1;U213.15

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