| 既有桩基荷载对邻近浅埋隧道开挖效应及支护内力影响的研究 |
| |
| 引用本文： | 安建永,项彦勇,贾永州.既有桩基荷载对邻近浅埋隧道开挖效应及支护内力影响的研究[J].岩土力学,2014,35(4):926-932. |
| |
| 作者姓名： | 安建永 项彦勇 贾永州 |
| |
| 作者单位： | 1. 北京交通大学 土木建筑工程学院，北京 100044；2. 中国建筑西南勘察设计研究院有限公司，成都 610000 |
| |
| 基金项目： | 国家自然科学基金资助项目(No. 50978019)。 |
| |
| 摘 要： | 建立了包括地层模型、桩基荷载模型、浅埋隧道开挖模型和支护模型以及桩基荷载、地层压力、地层沉降、支护应变量测装置的平面应变模型试验系统;通过模型试验,研究了不同水平、竖向相对位置处的既有桩基荷载对附近浅埋隧道开挖引起的地层压力重分布、地层沉降及隧道支护内力的影响特征。另外,采用FLAC3D软件,对模型试验及不同工况进行了数值模拟。结果表明:(1)与没有桩基荷载的自由地层中的隧道开挖试验相比较,地层中的既有桩基荷载会明显地改变邻近浅埋隧道开挖引起的地层压力重分布、地层沉降及隧道支护内力;(2)对于桩径和水平相对距离都相同,但桩长不同的桩基荷载,桩长与隧道埋深比值为1.0时,对隧道开挖效应影响最大,二者比值小于1.0时,其影响程度随着比值的减小而减小,二者比值大于1.0时,桩长的改变对隧道开挖效应影响较小;(3)对于桩径和桩长都相同的桩基荷载,对地层压力、地层沉降及支护内力的影响随桩基荷载与隧道的水平距离的减小而增大,桩基荷载距隧道的水平距离与隧道直径比值介于0.54.0时,桩基荷载对隧道开挖效应影响较大,隧道较危险,比值介于4.04.0时,桩基荷载对隧道开挖效应影响较大,隧道较危险,比值介于4.06.0时,影响较小,比值>6.0时,影响可以忽略不计。
|
| 关 键 词： | 模型试验 桩基荷载 隧道开挖模拟 数值分析 地层压力 地层沉降 隧道支护内力 |
| 收稿时间： | 2013-07-04 |
Study of influences of existing pile foundation loads on adjacent tunnel excavation and internal forces of primary support |
| |
| AN Jian-yong,XIANG Yan-yong,JIA Yong-zhou.Study of influences of existing pile foundation loads on adjacent tunnel excavation and internal forces of primary support[J].Rock and Soil Mechanics,2014,35(4):926-932. |
| |
| Authors: | AN Jian-yong XIANG Yan-yong JIA Yong-zhou |
| |
| Institution: | 1. School of Civil Engineering and Architecture, Beijing Jiaotong University, Beijing 100044, China; 2. China Southwest Geotechnical Investigation & Design Institute Co., Ltd., Chengdu 610000, China |
| |
| Abstract: | An layered earth model, a pile foundation load model, a shallow tunnel excavation model and an associated support model, together with plane strain model test system for measuring pile foundation load, soil pressure, soil settlement, and support strain are set up. Experiments are conducted to study the influences on soil pressure redistributions, soil set, tunnel crown settlements, and internal forces of the tunnel support caused by a nearby shallow tunnel excavation under the condition of various horizontal and vertical existing pile foundation loads. Moreover, the test process and different working conditions are simulated via the FLAC3D software. The results are as follows: (1) Compared to the tunnel excavation without pre-existing pile foundation loads, pre-existing pile foundation loads can significantly alter the soil pressure redistributions, soil settlements and internal forces of the tunnel support; (2) For pile foundation loads of different length, fixed pile diameter and horizontal position, when the ratio of pile length and tunnel depth is equal to 1.0, it causes a largest influence on the effect of tunnel excavation, in the case of the ratio less than 1.0, the influence decreases with the decrease of the ratio; when the ratio is beyond 1.0, the influence of the pile length change on tunnel excavation effect becomes smaller. (3) For file foundation loads of fixed pile diameter and length, the soil pressure, ground settlement and internal force of tunnel support increase with the decrease of the relative horizontal distance between the pile foundation loads and the tunnel. If the ratio of horizontal distance between the pile foundation loads and the tunnel and tunnel diameter is from 0.5 to 4.0, the tunnel will be in the danger. If the ratio of that is from 4.0 to 6.0, the influence on tunnel caused by the pile foundation loads will become lighter. If the ratio of that is beyond 6.0, the influence can be neglected. |
| |
| Keywords: | model test pile foundation load modeling of tunnel excavation numerical simulation soil pressure ground settlement internal force of tunnel support |
| 本文献已被 CNKI 等数据库收录！ |
| 点击此处可从《岩土力学》浏览原始摘要信息 |
| 点击此处可从《岩土力学》下载免费的PDF全文 |
|
