【作者】 葛桂琼；

【导师】 周安；

【作者基本信息】 合肥工业大学 ， 结构工程， 2010， 硕士

【摘要】 近年来,随着城市建设的快速发展,高层建筑的大量兴建以及城市地下空间的开发利用,必将带来大规模基坑工程的开挖和支护。由于地下管线密布对支护施工的影响以及施工面有限的限制,在工程中常采用桩锚支护结构体系。本文首先对与基坑支护相关的土压力计算基本理论和传统的支护结构设计方法进行综合分析和评价,然后针对桩锚支护结构形式,介绍了目前常用的计算其受力与变形的方法和理论。型钢混凝土支护桩(简称劲性桩)是一种在混凝土灌注桩中配置型钢的桩体,同时劲性桩配有锚杆形成桩锚组合支护体系。本文针对这种新的支护桩体进行有限元数值模拟,对比分析型钢混凝土支护桩与普通钢筋混凝土支护桩的受力性能。分析结果表明：与普通钢筋混凝土支护桩相比,型钢混凝土支护桩体的材料利用充分,桩体受力更加合理,其承载能力和延性也有了明显提升并且型钢混凝土支护桩施工简单,施工周期较短,在工程中值得推广和运用。在实际工程中,影响支护桩位移的外在因素是很多的。本文对影响型钢混凝土支护桩位移变化的参数进行了有限元分析。得出桩体混凝土等级、土体物理性质、锚杆设置和地下水位对支护结构的不同影响,并举具体工程实例加以验证。随着基坑工程的发展,基坑深度不断增加,平面形状也越来越不规则,基坑的空间效应也越来越多地影响到了基坑支护体系的设计及施工。本文通过有限元分析软件ANSYS建立了考虑空间效应的基坑开挖三维有限元模型,对支护桩在基坑开挖过程中的反应进行了分析研究,并探讨了基坑支护结构的角部效应、基坑几何尺寸对基坑支护结构的位移、内力分布的影响,对基坑的空间效应进行了系统的分析。表明将基坑空间效应的影响应用到支护结构设计中,可以适当减少支护结构的用量,从而降低成本,起到事半功倍的作用。更多还原

【Abstract】 In the recent years,along with the high-speed development of city construction,a great number of high-rises are constructed together with the exploitation of the underground structure,which surely brings large-scale excavation and support of the foundation pit project. Because of the influence of the underground pipeline which have a wide distribution around the project as well as the limitation about working surface,Pile-Anchor support system is often used in engineering. In this paper, the earth pressure calculation of the basic theory and the traditional structural design methods associated with the foundation pit have been analyzed and evaluationed comprehensively. In view of the Pile-Anchor support system,this article summarizes the impact when the supproting piles added supports,and describes the current design methods and theories on Pile-Anchor support system.Steel reinforced concrete supported piles (referred to stiff pile) which is configured the concrete piles with steel,form pile-anchor support system with anchor. In this paper, this new support system is detailedly analysed by large finite element software ANSYS. Compared with ordinary reinforced concrete support piles,Steel reinforced concrete support piles had higher bearing capacity by making full use of the tensile and piezotropy of the steel,and had better ductility. Steel reinforced concrete support piles had many advantages with simple construction and short construction period. It is worthy of being used widely in engineering practice.In the actual project, there are many external factors that impact displacement of pile. In this paper,the external factors that impact displacement of pile is detailedly analysed by large finite element software. Draw the different effects of support structure about pile concrete level, the physical properties of soil, anchor set-up and groundwater levels,and list specific examples of projects simultaneously.With the development of excavation,increasing depth of excavation and more and more irregularly shaped planar,the spatial effect of excavation increasingly affects the design and construction of foundation pit system. In this paper,the finite element program ANSYS is used to consider the spatial effect,and have do reaserch about the reaction of the supporting piles in the excavation process,and has also discussed the geometry size and structure angle department effect impact to the retaining wall displacement,the pressure distributed influence, have a systematic analysis for the spatial effect of the excavation. If the spatial effect of the foundation is applied to the design of supporting structure,we can decrease the amount of supporting structure and reduce costs.更多还原