超深地下连续墙钢筋笼吊装施工计算方法研究

发布时间：2018-01-21 11:26

本文关键词： 地下连续墙钢筋笼整体吊装简化计算　出处：《武汉理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着社会生产力的发展,大型深基坑工程越来越多,在大型地下工程中多采用地下连续墙施工技术,而钢筋笼吊装作为地连墙施工技术控制的重要一环,对地下连续墙施工的成败有着举足轻重的影响。未来地连墙钢筋笼吊装技术将随着超深地连墙技术的推广而得到广泛运用。对于超深地下连续墙钢筋笼的吊装,以往常常采用分段制作、吊装就位、分段连接的方式进行,其安全性比较好,但是效率低,成本高,且空中焊接质量不易得到保证,焊接后垂直度也不易控制。现代施工现场,吊装施工已经越来越多地采用整体一次性吊装就位的工艺方法,这种方法整体性好、施工周期短,效率高,节约材料和成本;但是超深基坑地下连续墙钢筋笼的整体吊装有其特殊性,钢筋笼本身质量大,长度长,单纯钢筋笼的单位刚度很低,吊点处笼体局部受力较大。在吊装过程中如果吊点设置不合理,加固措施不足,钢筋笼可能会有很大的纵向挠度,即钢筋笼顶端和尾端已经吊离地面,而钢筋笼中间部分还在平台上,继续强行吊装很容易发生钢筋笼散架等安全质量事故。同时,钢筋笼的吊装受力状态与其在地连墙中的受力形式是大不同的。因此,相应的吊装分析和设计研究是非常重要的。本研究以现行地下连续墙施工工艺和现有相关研究现状为基础,通过建立某项目中心主塔楼部分地下连续墙钢筋笼的整体有限元模型,对钢筋笼吊装过程中的整体受力变形性能进行分析,研究纵筋、横筋以及斜向腹筋在参与整体受力变形中的作用;通过推导偏位吊装下吊点力与钢丝绳力的表达式,对比偏位吊装下吊点力、钢丝绳力和垂直吊装下的吊点力、钢丝绳力,来研究钢筋笼吊装过程中可能会出现的偏位吊装的影响;建立梯形腹架和三角形腹架的钢筋笼模型,通过对比两种腹架受力变形性能,从而在钢筋笼腹架的设置上给出一些优化建议;在研究了钢筋笼整体受力变形性能的基础上,通过划分计算单元,将钢筋笼从整体结构简化为组合腹架;分析组合腹架的特性,通过选择分析模型,利用平衡条件以及变形协调条件,将组合腹架翼缘杆筋等效为矩形弦杆,实现组合腹架向平面单片腹架的简化;进一步分析单片腹架的特性,选择合适分析模型,实现单片腹架向单杆的简化。
[Abstract]:With the development of social productivity, there are more and more large-scale deep foundation pit projects. Underground continuous wall construction technology is often used in large underground projects, and steel cage hoisting is an important part of the construction technology control. In the future, the hoisting technology of reinforced cage will be widely used along with the extension of the technology of super-deep connecting wall, and the hoisting of reinforcement cage of super-deep diaphragm wall will be widely used. In the past, we often use the way of segmenting, hoisting, and connecting, its safety is good, but the efficiency is low, the cost is high, and the quality of air welding is not easy to be guaranteed. It is not easy to control the perpendicularity after welding. In modern construction site, lifting construction has been used more and more one-off hoisting position, this method has good integrity, short construction period and high efficiency. Saving materials and costs; However, the integral hoisting of reinforcement cage of underground continuous wall of ultra-deep foundation pit has its particularity. The reinforcement cage itself has large quality, long length, and the unit stiffness of simple steel cage is very low. In the process of hoisting, if the hoisting point is not reasonable and the reinforcement measures are insufficient, the reinforcement cage may have a great longitudinal deflection, that is, the top and the tail end of the steel cage have been hoisted off the ground. And the middle part of the steel cage is still on the platform. It is easy to happen the safety and quality accidents such as the reinforcement cage loose frame and so on. At the same time. The loading state of steel cage hoisting is different from the force form of reinforcement cage in the ground connecting wall. The research on hoisting analysis and design is very important. This research is based on the current construction technology of underground continuous wall and the current research status. Through the establishment of the integral finite element model of the steel cage of the underground continuous wall of the main tower building of a project, the deformation behavior of the steel cage during the hoisting process is analyzed, and the longitudinal reinforcement is studied. The role of transverse tendons and oblique web tendons in the deformation of the whole body; By deducing the expressions of the lifting point force and the wire rope force, the paper compares the lifting point force, the wire rope force and the vertical lifting point force and the wire rope force. To study the influence of skew hoisting in the process of steel cage hoisting. The reinforcement cage model of trapezoidal web frame and triangular web frame is established, and some optimization suggestions are given by comparing the deformation behavior of the two kinds of web frame. On the basis of studying the mechanical and deformation behavior of the whole steel cage, the reinforcement cage is simplified from the integral structure to the composite web frame by dividing the calculation elements. The characteristics of the combined web frame are analyzed. By selecting the analysis model and using the balance condition and the deformation coordination condition, the flange bar bar of the combined web frame is equivalent to the rectangular chord bar, which can simplify the combined web frame to the plane single web frame. Further analysis of the characteristics of the single-piece web frame, the selection of appropriate analysis model to achieve the simplification of the single-bar of the single-piece web frame.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU753

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