淮河超深双壁钢围堰荷载组合作用及力学特性分析

发布时间：2018-04-10 04:21

本文选题：双壁钢围堰　切入点：荷载组合　出处：《长安大学》2017年硕士论文

【摘要】：大跨径跨江河桥梁的发展,使得深水基础施工越来越普遍,这也对江河中防水围堰的施工技术提出了更高的要求。双壁钢围堰结构是一种重要的防水围堰形式,已被广泛采用于深水基础施工中。然而在钢围堰的设计中往往存在两方面的不足。一方面,采用保守的简化模型,将围堰结构的各构件单独进行承载力计算,再组成整体结构,忽略了围堰的整体受力,造成了材料浪费;另一方面,没有专门的钢围堰设计规范可供参考,对于围堰设计中的荷载取值和组合只能参考相关资料定义,缺乏统一性。双壁钢围堰结构的施工具有复杂性和不确定性,对于施工过程荷载最不利组合的确定具有十分重要意义。本文通过参考相关资料,推导出围堰结构在施工中所遇到的荷载的取值和施加方式,采取一种荷载组合方式,通过有限元软件Midas civil建立双壁钢围堰模型,模拟实际施工中的各种荷载,并进行组合,选取围堰着床、封底混凝土浇筑后、抽水一半以及抽水结束等四个工况,得出了围堰结构在不同施工工况下的受力特性;将监控实测结果与数值计算结果比较,对围堰结构受力特性进行验证,并在比较中发现差异,对荷载组合分项系数进行合理修正。本文还通过有限元软件Midas FEA建立封底混凝土和钢护筒的整体模型,得到其接触面粘结应力的分布规律,也为围堰结构的设计提供一定参考。本文探讨了隔仓板间距、水平体系间距对围堰受力的影响,对于双壁钢围堰结构的优化提供了参考思路。
[Abstract]:With the development of long-span bridge across rivers, the construction of deep-water foundation is becoming more and more common, which puts forward higher requirements for the construction technology of waterproofing cofferdam in rivers.Double wall steel cofferdam is an important waterproof cofferdam, which has been widely used in deep water foundation construction.However, there are two shortcomings in the design of steel cofferdam.On the one hand, the conservative simplified model is used to calculate the bearing capacity of the members of the cofferdam structure separately, and then the whole structure is formed, which neglects the overall force of the cofferdam and results in the waste of materials, on the other hand,There is no special code for the design of steel cofferdam for reference. For the load value and combination in the design of cofferdam can only refer to the relevant data definition lack of unity.The construction of double wall steel cofferdam structure is complicated and uncertain, which is very important for the determination of the most unfavorable combination of loads during construction.In this paper, by referring to relevant data, the value and mode of load applied to cofferdam structure in construction are deduced, and a kind of load combination mode is adopted. The model of double wall steel cofferdam is established by finite element software Midas civil.After simulating various kinds of loads in actual construction and combining them, four working conditions of cofferdam under different construction conditions are obtained, namely, after the cofferdam is placed in bed, the bottom concrete is poured, the pumping is half and the pumping is finished, and the mechanical characteristics of the cofferdam structure under different construction conditions are obtained.By comparing the measured results with the results of numerical calculation, the stress characteristics of cofferdam structure are verified, and the differences are found in the comparison, and the partial coefficients of load combination are corrected reasonably.In this paper, the integral model of bottom concrete and steel casings is established by the finite element software Midas FEA, and the distribution law of bond stress on the contact surface is obtained, which also provides a certain reference for the design of cofferdam structure.In this paper, the influence of the spacing between the spacers and the horizontal system on the stress of the cofferdam is discussed, which provides a reference for the optimization of the double wall steel cofferdam structure.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U445.556

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