树根桩在高挖边坡防护中的稳定性研究

发布时间：2018-01-06 02:12

本文关键词：树根桩在高挖边坡防护中的稳定性研究　出处：《长安大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着高速公路建设进程的不断延伸，高速公路网络的逐步形成，山区高速公路的修建也逐步普遍化。然而受到山区固有地形地质、自然环境条件的制约，，山区高速公路地质灾害发生频繁并且类型多种多样。在山区修建高速公路存在诸多安全隐患，尤其是在高挖边坡工程中。所以在山区修建高速公路时，需要特别注意高挖边坡的稳定性问题。本文以乐宜高速公路高挖边坡为依托工程，分析了高挖边坡的破坏形式及各类地质灾害的预报。利用FLAC3D建立数值模型，采用强度折减法，研究了树根桩的桩位、桩长、桩径等设计参数对高挖边坡稳定性的影响。结果表明：一级坡体中设置在距坡脚的1/3附近坡面处，多级边坡设置在离坡脚最近的平台附近，此时边坡的安全系数较高，且所需树根桩桩长较短、桩径较小；树根桩的桩长一定要穿过初始滑动面，且桩长大于临界桩长；对于不同的桩位，当桩长完全穿越新的滑动面时，边坡安全系数均大于1.8；越靠近坡脚的树根桩，增加桩径的效果越明显，而靠近坡顶时，设置斜树根桩更有利。采用极限平衡法和有限元法，选取典型高挖边坡，分析了框架梁防护和树根桩防护在不同工况下的稳定性并进行对比。结果表明：树根桩在高挖边坡防护上具有一定的优越性。
[Abstract]:With the continuous extension of highway construction process and the gradual formation of highway network, the construction of mountain highway is gradually generalized. However, it is restricted by the inherent terrain, geology and natural environment conditions. The geological disasters of highway in mountainous area occur frequently and are of various types. There are many hidden dangers in the construction of highway in mountain area, especially in the high excavation slope engineering. So, when building expressway in mountainous area. Special attention should be paid to the stability of high-excavated slopes. In this paper, based on the high excavation slope of Leyi Expressway, the failure form of high excavation slope and the prediction of various geological hazards are analyzed. The numerical model is established by FLAC3D and the strength reduction method is adopted. The influence of pile position, pile length, pile diameter and other design parameters on the stability of highly-excavated slope is studied. The results show that the first-grade slope body is located near the slope surface 1/3 from the foot of the slope. The multi-stage slope is located near the nearest platform at the foot of the slope, and the safety factor of the slope is high, and the length of the root pile is shorter and the diameter of the pile is smaller. The pile length of the tree root pile must pass through the initial sliding surface and the pile grows up to the critical pile length. For different pile positions, when the pile length passes through the new sliding surface completely, the slope safety factor is higher than 1.8; The more the root pile near the foot of the slope, the more obvious the effect of increasing the diameter of the pile is, but when near the top of the slope, it is more advantageous to set the inclined root pile. The limit equilibrium method and finite element method are used to select the typical high excavated slope. The stability of frame beam protection and root pile protection under different working conditions is analyzed and compared. The results show that the tree root pile has some advantages in high excavation slope protection.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.14;U417.1

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