深基坑支护论文：成都市百扬大厦深基坑支护数值模拟研究

1、深基坑支护论文：成都市百扬大厦深基坑支护数值模拟研究【中文摘要】随着经济环境的发展与人们居住环境要求的提高,近年来我国建筑、市政等工程得到飞速发展。在都市中,寸土寸金,因而在建筑向高空发展的同时,地下空间的利用也成为一个重要方向。这些地下空间和设施,包括高层及多层建筑的地下室、地下商业街、地下车库、地铁车站、越江隧道等各种形式。开发和建造这些地下空间和设施,首先要进行的就是大规模的深开挖,因此,作为保障深开挖进行的深基坑工程技术也得到了不断的发展。本文以百扬大厦深基坑工程为依托,就基坑的土压力、支护方案、支护结构参数等进行了较为全面的研究,获得了以下研究结果：(1)在分析传统土层物理力学参数厚

2、度加权简化方法存在的不足之处后,从支护结构内力等效的角度出发,提出了坑壁土层物理力学参数与支护结构内力等效相对应的简化计算原理与方法,并与传统土压力计算方法的计算结果进行了对比分析,表明本文提出的简化方法更为合理;(2)针对粘聚力较大的土层,用等值梁法来分析桩锚结构时寻求反弯点的困难,提出了等弯矩法来确定锚拉桩支撑点的位置及其支撑力值,经本基坑工程的论证,该方法效果较好；(3)运用有限差分软件FLAC3D,对深基坑开挖支护的全过程进行了三维模拟,分析了六种工况下围护结构的受力特性,研究了深基坑的变形规律。围护桩最大水平位移计算结果和监测结果基本一致;(4)深基坑工程空间效应FLAC分析表明：围

3、护结构变形呈现出较强的空间效应,基坑中部的围护结构水平位移最大,越靠近基坑的角点,围护结构的水平位移越小；水平支撑轴力分布也呈现出明显的空间效应,位于基坑中部的水平支撑轴力最大,离角点越近,水平支撑轴力越小。研究结果表明三维计算是分析深基坑空间效应的有效手段。【英文摘要】In recent years, Chinese construction and municipal engineering have been developing rapidly with the development of economic environment. In the city, because of t

4、he high cost of land, the use of underground space has become an important direction. The underground space and facilities, including the basement level and multi-storey buildings, underground shopping street, underground garage, subwaystations, and other forms of cross-river tunnel. Construction of

5、 the underground space and facilities, the first step is the large-scale excavation, therefore, as a guarantee of deep excavation of the deep excavation technology has been continuously developing.This text research on the earth pressure、bracing scheme and the parameter of the bracing structure rely

6、ing on this deep foundation ditchengineering.The main results gained can be summed up as follows:(1)Analyse the existed shortage of the thickness weighted simplified method about the physieal meehaniealparameter of the soil horizons first and then starting from theangle of equivalent internal force

7、of the bracing strueture, extraet the simplified ealculation Prineiple and method which is corresponding to the physieal mechanical parameter of the soil horizons and equivalent internal force of the bracing strueture.Comparing with the results which are ealculatedaccording to the traditional earth

8、pressure ealculation method, it indicate that the simplificd method extraeted in this text is more appropriate.(2)Aim at the diffieulty of looking for inflection point when using equivalent beam method to analyse the pile anehor strueture in soil horizons with high cohesive strength, extract mapping

9、 method and equivalent bending moment method to ensure the location and value of the bracing.The effect is yerified preferably in this foundation ditchengineering.(3) By the use of finite difference software FLAC3D, a three-dimensional simulation of the entire process ofexcavation and support of dee

10、p excavation is accomplished.The behavior of retaining structure is analyzed, and thedeformation laws of deep excavation is studied in six cases. Monitoring results and calculation results of the largest horizontal displacement of retaining pile are basically the same.(4) The spatial effect of deep

11、excavation is analyzed by FLAG, the result shows that:the spatial distribution of thebracing structure displacements and the axial force of the steel support has strong spatial effect:Spatial effect of the corner is strong.and the spatial effect of The central section weakens.the result show that th

12、e calculation ofthree-dimensional analysis of deep excavation is an effective means to study spatial effect.【关键词】深基坑支护 工程地质条件 有限差分法 FLAC3D 数值分析 土压力【英文关键词】deep foundation pit bracingEngineering geological conditions Finite difference method FLAC3D Numerical analysis Soil pressure【目录】成都市百扬大厦深基坑支护数值模拟研

13、究6-710-11Abstract7第一章 绪论10-14摘要1.1 引言1.3 1.2 深基坑工程的主要内容与特点11-12国内外研究现状121.4 本论文的主要研究工作12-142.1 工程概第二章 百扬大厦深基坑工程环境条件概况14-20况1414-16标16-17与难点17-202.2 工程环境条件14-172.2.2 场地地下水162.2.1 工程地质条件2.2.3 土层的工程特征指2.3 本基坑的特点3.1 常用2.2.4 场地的周边环境17第三章 基坑土压力分析20-323.1.1 朗肯土压力理论的土压力理论20-2621-233.1.2 库伦土压力理论23-243.1.3 基坑

14、水压力的计算24-253.1.4 根据建筑基坑支护技术规程3.2 坑壁土压力计算方3.2.2(JGJ120-99)的土压力计算方法25-26法的分析26-283.2.1 地面荷载的处理26-27朗肯理论和库伦理论的对比分析27-28算28-313.4 本章小结31-3232-4532-333.3 坑壁土压力的计第四章 百扬大厦深基坑4.2工程支护方案研究基坑支护的技术要求33-444.1 基坑支护的功能324.3 基坑支护设计计算4.3.1 基坑设计简述33-344.3.2 基坑支护结构的静力计算34-37计算37-444.3.3 百扬大厦深基坑支护结构的静力第五章 百扬大厦深基4.4 本章小结44-45坑支护的数值模拟分析45-67介45-485.1 有限差分法的基本原理简5.2.1 5.35.2 有限差分法软件FLAC_(3D)48-505.2.2 FLAC_(3D)的特点48-505.3.1 土体本构模型的确立FLAC_(3D)简介48数值模型的建立50-5750-52件52-5353-575.3.2 计算区域及单元划分、材料参数、边界及初始条5.3.3 围护桩、衬砌及预应力锚索的模拟5.4 基坑开挖模拟