格栅加筋土挡墙性状

发布时间：2018-07-10 17:25

本文选题：格栅 + 加筋土挡墙　；参考：《浙江大学》2014年博士论文

【摘要】：加筋土挡墙的破裂面、格栅拉力、土压力、变形对加筋土挡墙的设计非常重要,但目前设计很多都是靠经验。本文通过理论分析、数值模拟、模型实验、现场实验对格栅加筋土挡墙进行了研究。研究发现：加筋土挡墙破裂面由向上应力和向下应力产生并叠加而成,向上应力产生的破裂面一般由上下两段直线构成,破裂面的下半段从墙脚处斜向上方延伸,其与水平面的夹角呈45°+0.5φ,破裂面与竖向压力呈线性关系,竖向压力越大,破裂面越长。墙顶压力越大,破裂面的上半段位置越高,其从下半段的上端开始斜向墙面延伸。向下应力产生的破裂面是一条产生于墙面某个位置并斜向下方延伸的直线,它与水平面的夹角也呈45°+0.5φ。本文总结出一套计算、快速绘制破裂面的方法。加筋土挡墙墙背处的侧向土压力与理论计算的静止土压力基本一致,可以用墙背处的静止土压力进行挡墙的整体稳定性验算。但是强夯后墙背处的侧向土压力显著增大。由于格栅在加筋土中所起的作用逐渐变小,破裂面由下而上与水平面的夹角逐渐减小。同等条件下与直立加筋土挡墙相比,斜面加筋土挡墙的墙面位移和墙顶面的不均匀下沉都较小。挡墙的地基对挡墙墙面水平位移和墙顶面的不均匀下沉影响很大。斜面挡墙墙脚处的破裂面随墙面的倾斜而倾斜。三分之一墙高处的墙面水平位移最大,出现“鼓肚”现象,随着墙顶荷载的增大,墙面水平位移增大,上部墙面的水平位移更显著。在挡墙旁强夯会引起墙面较大的振动加速度,尤其是墙面顶点的水平加速度。夯点距墙面越近,振动加速度显著增大。强夯会引起格栅拉力增大,重锤低击可减少强夯对格栅的影响。碾压荷载会使中下部墙面发生较大的水平位移,而强夯会使碾压而成的加筋土挡墙墙面“回缩”。本文的理论、实验方法、结论可为进一步研究和挡墙设计提供参考。
[Abstract]:The fracture surface, grid tension, earth pressure and deformation of reinforced earth retaining wall are very important to the design of reinforced earth retaining wall. In this paper, theoretical analysis, numerical simulation, model experiment and field experiment are used to study the reinforced earth retaining wall. It is found that the rupture surface of reinforced earth retaining wall is produced and superimposed by the upward stress and the downward stress. The rupture surface produced by the upward stress is generally composed of two straight lines, and the lower half of the fracture surface extends diagonally from the bottom of the wall to the top. The angle between the plane and the horizontal plane is 45 掳0.5 蠁, and the fracture surface is linearly related to the vertical pressure. The larger the vertical pressure is, the longer the fracture surface is. The higher the pressure on the top of the wall is, the higher the position of the upper half of the rupture surface is, and the higher the upper end of the lower part is, the more inclined it is to the wall. The fracture surface produced by downward stress is a straight line which originates from a certain position of the wall and extends diagonally downwards. The angle between it and the horizontal plane is also 45 掳0.5 蠁. In this paper, a set of calculation methods for fast drawing of fracture surface is summarized. The lateral earth pressure at the back of the reinforced earth retaining wall is basically consistent with the static earth pressure calculated theoretically, and the overall stability of the retaining wall can be checked by the static earth pressure at the back of the wall. However, the lateral earth pressure at the back of the wall increases significantly after dynamic compaction. The angle between the fracture surface and the horizontal plane from the bottom to the top decreases gradually because the grid plays a smaller role in the reinforced soil. Compared with the vertical reinforced earth retaining wall under the same conditions, the wall displacement and the uneven subsidence of the top surface of the inclined reinforced earth retaining wall are smaller than those of the vertical reinforced earth retaining wall. The foundation of the retaining wall has great influence on the horizontal displacement of the wall surface and the uneven subsidence of the top surface of the wall. The cracked face at the foot of a inclined retaining wall tilts with the slope of the wall. The horizontal displacement of the wall at the height of 1/3 wall is the largest and the phenomenon of "bulging belly" appears. With the increase of the load on the top of the wall, the horizontal displacement of the wall surface increases, and the horizontal displacement of the upper wall is more obvious. Dynamic compaction next to the retaining wall will cause the vibration acceleration of the wall, especially the horizontal acceleration at the top of the wall. The closer the tamping point to the wall, the greater the vibration acceleration. Dynamic compaction will increase the grid tension, and the low impact of heavy hammer can reduce the influence of dynamic compaction on grid. The rolling load will make the middle and lower part of the wall face larger horizontal displacement, and the dynamic compaction will make the reinforced earth retaining wall surface "shrink". The theory, experimental method and conclusion of this paper can provide reference for further research and design of retaining wall.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU476.4

【参考文献】