大型堆煤软土场地群桩基础受力变形特性数值分析与安全性评价

发布时间：2018-01-12 11:21

本文关键词：大型堆煤软土场地群桩基础受力变形特性数值分析与安全性评价　出处：《大连海事大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着我国经济突飞猛进,在工业厂房、公路路堤、道桥、港口码头经常出现堆载甚至超载的情况。在软土地基中,桩基础在堆载作用下不仅会产生侧向位移,还将产生较大的附加弯矩,这对于桩基的自身受力情况以及上部结构的安全使用产生安全隐患。因此,有必要研究软土地区堆载作用下桩基的受力特性,评价其是否满足稳定性和承载力要求,并提出合理化建议。本文以马来西亚BALINGIAN(2×300MW)燃煤电站储煤场软基处理为工程背景,基于大型通用有限元软件ABAQUS,考虑桩土相互作用的影响,通过建立二维、三维有限元分析模型,对储煤场群桩基础的受力特性进行研究,在此基础上进行参数化分析。具体研究内容包括:(1)建立了软土地基中堆煤场地群桩基础简化二维有限元分析模型,对无堆煤荷载作用和有堆煤荷载两种工况下土体位移、桩基位移及内力进行了系统分析,研究堆煤荷载对桩基变形及受力的影响规律,与实际情况对比确定建模的合理性。(2)结合施工勘测报告,选取三个典型断面,建立二维和三维有限元模型,对软土弹塑性本构地基-线弹性和弹塑性群桩基础的受力特性进行对比分析,并在此基础上结合规范要求对群桩基础的稳定性做出合理性评价。(3)基于以上分析,选取最不利断面,综合考虑工程实际情况,以淤泥质土层弹性模量作为参变量,研究其对群桩基础受力及变形的影响规律,在此基础上对真空预压处理后地基中桩基承载力进行验算,为相关工程的进一步设计与施工提供参考。
[Abstract]:With the rapid development of economy in our country, there is often overloading or overloading in industrial factory building, highway embankment, road bridge, port wharf. In soft soil foundation, pile foundation will not only produce lateral displacement under the action of surcharge. There will also be a larger additional bending moment, which will cause safety hidden danger for the pile foundation and the safety use of the superstructure. Therefore, it is necessary to study the mechanical characteristics of the pile foundation under the surcharge in soft soil area. To evaluate whether it meets the requirements of stability and bearing capacity, and to put forward reasonable suggestions. This paper takes the soft foundation treatment of coal storage yard of Malaysia BALINGIAN(2 脳 300MW coal power station as the engineering background. Based on the finite element software Abaqus and considering the influence of pile-soil interaction, a two-dimensional and three-dimensional finite element analysis model is established to study the mechanical characteristics of pile group foundation in coal storage yard. On the basis of this, parametric analysis is carried out. The concrete research contents include: 1) the simplified two-dimensional finite element analysis model of pile group foundation in pile yard and ground in soft soil foundation is established. The displacement of soil, displacement of pile foundation and internal force under two working conditions of coal load without pile and pile coal load are analyzed systematically, and the influence of pile coal load on deformation and force of pile foundation is studied. Compare with the actual situation to determine the rationality of the modeling. 2) combined with the construction survey report, select three typical sections, establish two-dimensional and three-dimensional finite element model. In this paper, the stress characteristics of elastic elastic and elastoplastic pile group foundation of soft soil are compared and analyzed. Based on the above analysis, the most unfavorable section is selected and the actual situation of the project is considered comprehensively. Taking the elastic modulus of silt soil as parameter, the influence of elastic modulus on the bearing capacity and deformation of pile group foundation is studied, and the bearing capacity of pile foundation after vacuum preloading treatment is checked. To provide reference for further design and construction of related projects.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU473.1

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