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地下连续墙的理论计算与工程实测对比分析

Continuous Diaphragm Wall of Theoretical Calculations and Engineering Measure of Contrasting and Analysis

【作者】 靳雪梅

【导师】 牛志荣;

【作者基本信息】 太原理工大学 , 岩土工程, 2009, 硕士

【摘要】 随着改革开放的不断深入以及我国国民经济的快速健康发展,国内的城市化建设也进入了一个更新、更快的发展时期,城市的数量、规模及其人口也都有了巨大的增长。这就使得开发三维城市空间发展要求愈益迫切,它最直接地表现为城市建筑物、构筑物不断地向高空发展和向地下延伸,而且在未来它仍将是城市发展的趋势。目前各类用途的地下空间已经在世界各大中城市得到大量的开发利用,同时,也会遇到一些大中型的基坑工程。大量的基坑工程实践表明,仅仅依靠理论分析和经验估计难以完成经济可靠的基坑支护设计和施工,施工监测就显得十分重要。地下连续墙作为深基坑的一种支护型式,其受力与钢板桩、桩排式灌注桩等挡土结构有许多相似之处,但因为地下连续墙入土深、刚度大,施工过程的工况多,所以设计计算时又有其本身的特殊性。本文是以天津港南疆港区神华煤炭码头建设工程两座廊道的地下连续墙工程为研究背景,以地下连续墙的设计计算方法在实际工程中的应用为研究重点,对地下连续墙的水平位移、垂直位移、顶撑应力等进行了有限元计算,并用实测数据进行了验证。总结提炼了目前通用的地下连续墙的设计计算方法,将地下连续墙的静力计算理论分为以下二类:(1)古典法——荷载结构法;(2)弹性抗力法——有限单元法,介绍了这两类方法的设计原理与计算步骤,并根据地下连续墙施工过程的工况多的特点,引入具体实例详细说明各工况受力特点及计算方法。根据工程需要,对二座翻车机房廊道的八个观测断面和20个观测点,进行了土压力、墙顶水平位移、墙顶垂直位移、墙体侧向变形和顶撑应力的监测,测得了随着时间和挖深的变化,在不同工况时,土压力、墙体变位和顶撑应力的变化情况。并采用古典法求得1-A断面的支撑轴力,再利用二维有限元程序PLAXIS对二座廊道地下连续墙的四个断面进行了理论计算分析,得到不同工况时的墙体变位和顶撑应力。通过对工程监测数据和理论计算结果进行对比分析可知,古典法计算支撑轴力较监测数据偏小,利用有限元计算得的墙体水平位移变形曲线与工程实测较为接近,而将有限元计算所得的墙体垂直位移和支撑应力用于工程实际也是偏于安全的。

【Abstract】 With the deepening of reform and opening up as well as China’s national economy, rapid and healthy development of urbanization in the domestic construction has entered a newer, faster development times, the number of cities, the size of its population has been tremendous growth. This makes the development of three-dimensional urban space requirements of the development of increasingly urgent, it is most directly reflected in city buildings; structures to keep the high-altitude development and extension of the underground, but in the future it will continue to be the trend of urban development. At present, various uses of underground space is already the world’s major cities has been a lot of development and utilization will also encounter some of the large and medium-sized excavation.A large number of foundation engineering practice shows not rely on theoretical analysis and experience is estimated to complete the economic and reliable foundation pit design and construction, construction monitoring is essential. Continuous Diaphragm Wall as a deep foundation pit type, and its force with the Steel Sheet pile, pile-ROW pile retaining structure, etc. There are many similarities, but because buried deep Continuous Diaphragm Wall, stiffness, and the construction process working condition, so the design of the calculation has its own particularity.This article is based on Tianjin Port Nanjiang Port Shenhua Coal Terminal 2 corridor construction of Continuous Diaphragm Wall for the research background to the design of Continuous Diaphragm Wall method of calculating the actual engineering focus, Continuous Diaphragm Wall of the horizontal displacement, vertical displacement, stress and so on up to the top of the finite element method, and verify the measured data.Aggregate refining the current generic design of Continuous Diaphragm Wall method of calculation will have Continuous Diaphragm Wall of static calculation theory is divided into the following two categories: (1) the classical method——load-structure method; (2) Elastic Resistance method - finite element method, introduced the two types of methods of design principle and calculation procedures in the light of the construction process of Continuous Diaphragm Wall of the working conditions and more features, the introduction of specific examples in detail the status of the workers affected by the characteristics and the method of calculating power.Based on the engineering needs of car-dumper shed and corridor 8 observation section and 20 observation points, a horizontal displacement of wall’s top , vertical displacement of wall’s top, lateral wall deformation and top up the stress monitoring, measured as the time and deepening the changes in the different working conditions, the wall deformation and top up the changes in stress. Obtained using the classical 1-A cross-section of the support shaft, and re-use two-dimensional finite element program for the two corridor PLAXIS Continuous Diaphragm Wall of the four sections the theoretical calculation and analysis, when different conditions of the wall change bit and top up the stress. Works by monitoring data and calculated results were analyzed, we can see that the classical method to calculate the axial force to support the monitoring data than too small, the use of finite element calculated horizontal displacement of the wall deformation curve and the project is closer to the measured, and the finite element calculations vertical displacement of the wall stress and support for the project is biased towards the actual security.

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