基于ABAQUS的基坑开挖对邻近管线变形影响的数值分析

发布时间：2018-02-21 12:42

本文关键词： 有限元分析基坑开挖管线变形影响因素空间效应被动区加固　出处：《天津城建大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着经济的发展，由于城市人口众多，建筑物密集，各类地下管线错综复杂，城市建设基坑开挖不断加深加大，深基坑开挖的安全问题和对周边环境的影响成了岩土工程研究的一个重要的课题。本文在前人研究的基础上，运用有限元软件ABAQUS就深基坑开挖对周围地下管线的影响这一课题进行了研究分析。主要内容和结论如下： 1.首先介绍了ABAQUS有限元软件在基坑开挖中的应用，对三维有限元中单元类型、本构模型的选取，初始应力的设置以及开挖步骤等关键技术分别进行了阐述。 2.本文主要通过采用ABAQUS软件建立土体、围护结构及其邻近地埋管线为一体的3D有限元模型。研究分析了分步开挖、不同管材、距离基坑远近、不同埋置深度以及周边堆载等不同因素对地下管线变形的影响，通过对数值模拟结果进行对比分析，得出管线的变形随着开挖深度的增加而增加；管线的变形与其弹性模量的大小有关；基坑对邻近管线的影响范围大致在3倍的开挖深度；基坑施工过程中尽量减少在基坑周边土体堆载，，控制基坑开挖变形对周边环境的影响，减少事故的发生。 3.结合工程实例，运用ABAQUS建立了内撑式支护结构基坑开挖的三维有限元模型，通过把模拟结果和具体监测数据对照，验证了模型有一定的准确性。对基坑开挖的空间效应对邻近地下管线的位移影响，得出管线的变形受开挖顺序和基坑端部坑角效应的影响明显，管线在基坑坑角部位受其影响的范围在1.5倍的开挖深度内。并对基坑被动区加固的合理范围进行了对比分析，采用被动区土体加固可以有效的减小其对周围地埋管线的位移，结合本工程实际情况，认为加固深度为6m宽度为7m时是能满足加固效果前提下最经济的范围。通过本文的初步研究，大型基坑开挖对周围地下管线的影响取得了初步认识，为以后信息化施工指导工程实践提供了一定的理论基础，对于实际基坑工程中对周围地下管线的保护设计及今后的研究都有一定的参考意义。
[Abstract]:With the development of economy, because of the large population, dense buildings and complicated underground pipelines, the excavation of foundation pit in urban construction is deepening and increasing. The safety of deep foundation pit excavation and its influence on the surrounding environment have become an important subject in geotechnical engineering. The influence of deep foundation pit excavation on underground pipeline is studied and analyzed by using finite element software ABAQUS. The main contents and conclusions are as follows:. 1. The application of ABAQUS finite element software in excavation of foundation pit is introduced. The key techniques such as element type, selection of constitutive model, setting of initial stress and excavation steps in 3D finite element are described respectively. 2. The 3D finite element model of soil mass, retaining structure and its adjacent buried pipe line is established by using ABAQUS software. The paper studies and analyzes the step by step excavation, different pipe materials, and the distance from the foundation pit. Through the comparison and analysis of the numerical simulation results, it is concluded that the pipeline deformation increases with the increase of excavation depth. The deformation of pipeline is related to its elastic modulus; the influence of foundation pit on the adjacent pipeline is about 3 times the depth of excavation; during the construction of foundation pit, the heaped load of soil around the foundation pit is reduced as far as possible. Control the influence of excavation deformation on the surrounding environment and reduce the occurrence of accidents. 3. Combined with the engineering example, the three-dimensional finite element model of the excavation of the foundation pit of the braced retaining structure is established by using ABAQUS. The simulation results are compared with the specific monitoring data. The accuracy of the model is verified. The displacement of the adjacent underground pipeline is affected by the spatial effect of excavation, and the deformation of the pipeline is obviously affected by the excavation sequence and the pit angle effect at the end of the foundation pit. The influence range of pipeline on pit corner is 1.5 times of excavation depth. The reasonable range of reinforcement in passive zone of foundation pit is compared and analyzed. The displacement of pipeline buried in surrounding area can be effectively reduced by soil reinforcement in passive zone. Combined with the actual situation of the project, it is considered that the most economical range under the premise of the reinforcement effect can be obtained when the depth of reinforcement is 6m and the width is 7m. Through the preliminary research in this paper, the influence of large excavation on the underground pipeline around the foundation pit has been preliminarily understood, which provides a certain theoretical basis for guiding the engineering practice of the information construction in the future. It has certain reference significance for the protection design and future research of underground pipeline in actual foundation pit engineering.
【学位授予单位】：天津城建大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU753;TU990.3

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