摘要
加筋土挡墙是由拉筋、墙面板和填土构成的一种新型复合支挡结构物。相对于传统的重力式挡土墙，加筋土挡墙为一种柔性结构，具有较好的变形协调性和抗震性能，对地基的承载能力要求也不高，且具有很好的经济性和造型美观性等一些其他结构无法比拟的优越性。因此，被广泛应用与公路、水利、城市建设和铁路等工程中。
加筋挡土墙虽有较好的抗震性能，但并非能够抵抗任何等级的地震作用。对于规范要求的抗震设计加筋土挡墙工程，在设计计算时须考虑地震力对其的影响。根据现行相关规范，地震烈度在6度以上的地区，加筋土挡墙应进行抗震设计。采用拟静力法来考虑地震作用，不计竖向地震力的影响，只需考虑水平地震力作用。
本文对加筋挡土墙的构造、特点及其发展应用状况作了概述。通过加筋挡土墙的构造，分析了加筋挡土墙的加固机理和破坏模式。加筋土本身是一种复合结构，在工作态下，各组成部分之间的相互影响使其具有一定的复杂性。
关键词：加筋土挡墙；地震力；稳定性分析与计算
Abstract
Reinforced earth retaining wall is a new composite supporting structure comprised of reinforcement, wall sheathing and filling. Compared with traditional gravity retaining wall, the reinforced earth retaining wall is a flexible structure with better deformation compatibility and seismic behavior.Moreover, the reinforced earth retaining wall requires low foundation bearing capacity and has advantages like economical efficiency as well as better appearance which are incomparable to other structures. Therefore, it is widely used in the construction of road, water conservancy, city construction and railway.
The reinforced earth retaining wall having good seismic behavior does not mean it can resist the earthquake effect of any grade. To reinforced earth retaining wall with seismic design required in the specification, the effect of seismic force should be taken into account in design calculation. According to the current standard, in the area where seismic intensity is level six or above, the reinforced earth retaining wall should be designed to resist earthquake. If adopting pseudo-static method to calculate seismic effect, the effect of vertical seismic force should be neglected, only calculating the effect of horizontal seismic force.
This thesis gives a brief introduction to the structure, characteristics, development and application of the reinforced earth retaining wall, at the same time, analyzes its reinforcement mechanism and failure modes through the structure of the reinforced earth retaining wall. Reinforced earth is a composite structure itself, and interrelationship of each component makes it relatively complex in the working state.
Key words: Reinforced earth retaining wall; Seismic force ; Stability analysis and calculation
目录
第1章 绪论 .................................................................................................................. 1
1.1 支挡结构与挡土墙 ........................................................................................ 1
1.1.1 支挡结构 ............................................................................................. 1 1.1.2挡土墙 .................................................................................................. 1 1.2加筋土挡墙的特点和适用性 ......................................................................... 2
1.2.1 加筋土挡墙的特点 ............................................................................. 2 1.2.2 加筋土挡墙的适用性 ......................................................................... 2 1.3加筋土挡墙的应用与发展 ............................................................................. 2
1.3.1国外发展概况 ...................................................................................... 2 1.3.2 国内发展概况 ..................................................................................... 3 1.3.3 加筋土技术的不足 ............................................................................. 4 1.4 本课题设计的背景、目的及意义 ................................................................ 4
1.4.1 背景 ..................................................................................................... 4 1.4.1 目的与意义 ......................................................................................... 5
第2章 加筋土挡墙的设计原理 ................................................................................. 6
2.1 加筋土挡墙的构造 ........................................................................................ 6
2.1.1 墙面板 ................................................................................................. 6 2.1.2 拉筋 ..................................................................................................... 6 2.1.3 填料 ..................................................................................................... 7 2.2 加筋土挡墙的设计原理 ................................................................................ 8
2.2.1 摩擦原理 ............................................................................................. 9 2.2.2 准粘聚力原理 ................................................................................... 10 2.3 加筋土挡墙的破坏模式 .............................................................................. 11 2.4 破裂面的确定 .............................................................................................. 13 2.5 加筋土挡墙设计计算时的基本假定 .......................................................... 15 第3章 加筋土挡墙的设计理论和计算方法 ........................................................... 16
3.1 稳定性分析计算方法 .................................................................................. 16
3.1.1 拟静力法 ........................................................................................... 16 3.1.2 数值分析法 ....................................................................................... 17 3.2 内部稳定性分析计算 .................................................................................. 18
3.2.1 土压力计算 ....................................................................................... 18 3.2.2 作用在拉筋上的竖向压应力计算 ................................................... 21 3.2.3 地震力计算 ....................................................................................... 22 3.2.4 拉筋拉力计算 ................................................................................... 23 3.2.5 拉筋抗拔力计算 ............................................................................... 23 3.2.6 拉筋长度的确定 ............................................................................... 23 3.2.7 拉筋抗拔稳定检算 ........................................................................... 24 3.2.8 拉筋抗拉强度检算 ........................................................................... 24 3.2.9 墙面板内力检算 ............................................................................... 25 3.2.10 连接件内力检算 ............................................................................. 26 3.3 外部稳定性分析计算 .................................................................................. 27
3.3.1 基底抗滑稳定性计算 ....................................................................... 27 3.3.2 倾覆稳定性计算 ............................................................................... 28 3.3.3 基底承载能力计算 ........................................................................... 28
第4章 加筋挡土墙设计 ........................................................................................... 30
4.1 工程资料 ...................................................................................................... 30
4.1.1 工程概况 ........................................................................................... 30 4.1.2 工程条件 ........................................................................................... 30 4.2设计方案 ....................................................................................................... 31
4.2.1 加筋土挡墙方案的选择 ................................................................... 31 4.2.2 填料与拉筋的选取 ........................................................................... 32 4.3 初步确定拉筋长度 ...................................................................................... 33
4.3.1 墙后总地震主动土压力计算 ........................................................... 33 4.3.2 基底抗滑稳定 ................................................................................... 33 4.3.3 抗倾覆稳定 ....................................................................................... 34 4.4 荷载计算 ...................................................................................................... 34