大直径筒仓滑模与仓顶钢结构整体抬升施工技术

针对大直径筒仓工程施工问题,将仓顶钢结构与仓壁滑升模板系统进行整体施工设计,先在地面通过统一的承载和变形协调控制措施,在仓壁滑升模板上设置抬升支座,布置抗水平推力拉杆系统,形成一个大直径筒仓主体施工稳定承载体系,滑升施工过程中严格控制滑升偏差精度,监测空间钢结构整体提升的支座反力和与提升装置的变形,一次性完成大型筒仓的仓壁施工和仓顶钢结构整体安装,并运用循环降落法有效地解决了仓顶钢结构整体屋盖的就位问题。     

超大直径筒仓仓壁滑模仓顶钢结构托带施工技术

结合工程案例,对超大直径筒仓仓壁滑模仓顶钢结构托带的施工方法作了介绍,结合其施工原理,对其施工工艺流程及施工操作要点进行了归纳总结,指出该施工方法具有操作简单、进度快、效率高等优点。     

大直径筒仓滑模与仓顶钢结构整体抬升施工技术

随着我国整体经济建设的蓬勃发展,我国建筑业实现了较为长足的进步,大直径筒仓非定型平台滑模施工技术得到进一步完善。为此简单介绍大直径筒仓滑模与仓顶钢结构整体抬升施工技术,详细阐述该施工技术的原理、技术工艺及安装措施。     

浅圆仓斜顶伞形钢结构支撑系统施工技术

某粮食储仓为筒形尖顶结构,仓顶板屋面及仓壁圆环外侧悬挑天沟施工难度大,危险性高,混凝土浇筑质量不易控制。施工采用伞形钢结构支撑,将传统的从地面开始搭设钢管架改为从支撑平台顶部开始搭设钢管架,在工程实践中取得了良好的成效。介绍了该技术的原理与施工工艺,主要包括伞形钢支撑系统组装、提升就位并架设挂钩式三脚架、仓顶板施工等。     

筒仓仓顶结构的优化设计与施工

结合工程实例 ,介绍筒仓仓顶结构的选形设计和采用柔性施工平台及格构桁架式梁骨架进行仓顶结构施工的过程     

浅圆仓仓顶钢桁架支撑体系的设计与施工

为确保仓顶结构施工安全、减少钢管使用量、有效提升施工速度,设计了一种中心立柱+钢桁架的支撑体系。通过在杭州市仁和粮食储备库建设工程的施工应用,证实该支撑体系构造简单,可重复利用,拆除便利,并可通过桁架单元的组装调节适应多种大直径浅圆仓仓顶施工需求,避免了类似工程仓顶施工平台搭设周期长、拆除工程量大、安全隐患高等缺点,对类似工程的施工具有一定的参考意义。     

沉箱仓格牛腿设计优化

沉箱于仓格顶部设计钢筋混凝土牛腿,用于支撑仓格盖板以作为胸墙底模板支撑.钢筋混凝土牛腿在施工过程中不利于沉箱预制内模安装、拆除.通过设计优化,采用钢牛腿代替钢筋混凝土牛腿,简化预制内模安装、拆除,实现仓格盖板支撑,达到施工便利、节省成本、缩短工期的目标,可供同类工程借鉴.     

钢结构浅圆仓仓盖的支撑布置形式分析

钢结构的浅圆仓仓盖是一种新型的空间仓盖结构,其支撑布置形式有许多种,但从综合角度考虑,哪种支撑布置形式相对比较合理,目前还不十分清楚,这给工程设计带来很大不便.通过对工程常用的4种支撑布置形式的钢结构仓盖进行计算、分析和比较,确定出一种相对经济合理的仓盖支撑布置形式.     

钢结构浅圆仓仓盖的支撑布置形式分析

钢结构的浅圆仓仓盖是一种新型的空间仓盖结构,其支撑布置形式有许多种,但从综合角度考虑,哪种支撑布置形式相对比较合理,目前还不十分清楚,这给工程设计带来很大不便。通过对工程常用的4种支撑布置形式的钢结构仓盖进行计算、分析和比较,确定出一种相对经济合理的仓盖支撑布置形式。     

高空钢结构穹顶独立格构支撑平台辅助安装技术应用

针对工程中遇到的高大中空钢结构穹顶安装施工的难点,提出通过设立钢结构独立格构支撑平台,结合结构圈周环形悬挑支撑平台,并在支撑平台上搭设落地钢管脚手架体,辅助钢结构穹顶进行安装施工,有效解决高空作业平台搭设和后期拆除难度大的问题,为类似工程的施工提供了思路参考。钢结构独立格构平台支撑体系采用大型有限元结构分析软件计算分析,确保了支撑系统的结构安全。     

上承式钢管混凝土拱桥的动力特性分析

主要研究恩施龙桥特大桥上承式钢管混凝土拱桥的动力特性,并分析了主拱圈含钢率、横撑面积变化、桥面宽度变化几个因素对上承式拱桥的频率影响。通过分析得知:上承式钢管混凝土拱桥的桥面与主拱圈的振动基本一致;主拱圈的含钢率与横撑面积变化对横向刚度影响不明显,而可通过适当增加桥梁宽度来提高桥梁的横向刚度。     

An experimental study on structural performance evaluation of steel wire-integrated deck plate

Recently, due to the decreased work term and the convenience of construction work, the steel wire-integrated deck plate has been widely used in the construction sites in Korea. Most of all, owing to its good stiffness and economic consideration, the steel wire-integrated deck plate system has become very popular in recent years. This research suggested the new-type shear connector that can perform the roles of vertical bar and shear connector at the same time to obtain safety on construction load of the steel wire-integrated deck plate and improvement on constructability, and used many variables such as the location of lattice end and diameter of the lattice bar to evaluate the structural safety of the steel wire-integrated deck plate in construction step. The test results show that the new-type shear connectors sufficiently perform the roles of the vertical bars.     

闵浦大桥上层钢桥面铺装力学分析与优化设计

以沥青混合料铺装层的最大拉应力、铺装层与钢桥面板间最大剪应力等为控制指标,对闵浦大桥双层桥面的上层钢桥面裸板及铺装层进行了力学响应分析。计算结果表明:轮载作用下正交异性钢桥面板的力学响应具有显著的局部特征,与荷载作用位置密切相关;上层钢桥面上弦杆宽度范围内局部的变形量接近0.8mm,对铺装层的受力不利,应进行加劲处理;上层钢桥面上弦杆靠近轮迹带的支撑点和T型纵向加劲肋与钢表面板的交汇点为钢桥面铺装受力最不利点,应进行优化设计。最后提出:对上弦杆部分的钢桥面板进行局部加劲处理,供载重骑车行驶的外侧两车道的钢桥面板厚度宜采用16mm。     

大跨钢桥桥面铺装结构受力分析

桥面铺装试验模型的横断面是两边各有一个闭口肋,中间有三个开口肋的结构,横向具有刚度不均匀性,不宜采用正交异性板弯曲理论进行计算。本文根据虎门大桥桥面铺装及室内试验模型的特性提出了钢桥面铺装力学分析方法,为钢桥面铺装设计与施工提供了一定的理论依据。     

高速铁路钢桁梁桥正交异性整体钢桥面板有效宽度的计算原则

对比现有国内外钢桥设计规范中计算钢桥面板有效宽度的计算方法和公式。分析普通铁路钢桁梁桥纵横梁明桥面系和高速铁路钢桁梁桥正交异性整体钢桥面系传力途径和受力特点的不同。得出现有规范中的公式只能计算平面受弯构件,如简支梁和连续梁的有效宽度,不适用于正交异性整体钢桥面系杆件的结论。在上述基础上,提出了计算正交异性整体钢桥面板有效宽度的原则。     

钢桥面铺装层结构设计指标近似计算新方法

在行车荷载作用下,钢桥面铺装层的受力与变形较一般公路沥青路面或机场道面复杂得多,也是钢桥面铺装层结构设计的一个重要因素。从使用条件、工程实践、试验研究和受力特点等角度出发,提出钢桥面铺装层结构设计指标:一是铺装层拉应力,二是铺装层表面局部挠跨比。采用有限元方法建立在车载作用下钢桥面铺装层的力学响应计算模型。在结构设计参数常用取值范围内,对不设纵隔板和设置纵隔板两种常用钢桥面铺装层的结构设计指标关键影响因素进行正交敏感性分析。同时,通过逐步线性回归方法拟合出钢桥面铺装层结构设计指标的近似计算公式。得到的近似计算公式的精度检验和工程实例分析结果表明,近似计算公式精度很好,满足工程设计和理论研究的需要。研究结果可为钢桥面铺装层结构设计提供近似计算的新方法。     

Fatigue evaluation of steel-concrete composite deck in steel truss bridge——A case study

An innovative composite deck system has recently been proposed for improved structural performance. To study the fatigue behavior of a steel-concrete composite bridge deck, we took a newly-constructed rail-cum-road steel truss bridge as a case study. The transverse stress history of the bridge deck near the main truss under the action of a standard fatigue vehicle was calculated using finite element analysis. Due to the fact that fatigue provision remains unavailable in the governing code of highway concrete bridges in China, a preliminary fatigue evaluation was conducted according to the fib Model Code. The results indicate that flexural failure of the bridge deck in the transverse negative bending moment region is the controlling fatigue failure mode. The fatigue life associated with the fatigue fracture of steel reinforcement is 56 years. However, while the top surface of the bridge deck concrete near the truss cracks after just six years, the bridge deck performs with fatigue cracks during most of its design service life. Although fatigue capacity is acceptable under design situations, overloading or understrength may increase its risk of failure. The method presented in this work can be applied to similar bridges for preliminary fatigue assessment.     

A systematic approach towards the structural behaviour of a lightweight deck–side shell system

Lightweight structures are increasingly used for high-speed ships. This paper presents a systematic approach to analyse the structural behaviour of a lightweight deck–side shell system using high strength steel. An analytical model of the deck–side shell system was first given, which includes the effects of stiffeners for the deck and side shell, the support conditions of the centreline girder (CL-girder), the influence of transverse beams, and the interaction between the side shell and the lightweight deck as parts of problems to the solution. By changing several geometric parameters, the sensitivity of both overall and local stress and deflection for the deck–side shell system was investigated. The different geometric parameters analysed comprise the influence for variation in the thickness of the web for transverse beams, longitudinal stiffeners and the CL-girder, the thickness of lower flange for the transverse beam and, the thickness for the panel. Furthermore, the influence of the lightweight deck and loads from the deck above on the side shell, the effects of the side shell and loads from top deck on the deck, the support conditions for the CL-girder, and the influence of deck loads on the eigenmodes were also analysed. By evaluating the results obtained from FE simulation, the support conditions of the CL-girder, the thickness of the panels and the lower flange of the transverse beams were found to be the most relevant parameters affecting both the stress and the deflection distribution of the structure. The dynamic characteristics of the structure were also analysed. The FE analysis concerning buckling of the structure was present. The results enable naval architects and structural engineers to design new extreme lightweight deck structure more reliable and economical. And some suggestions for future research are also given.     

钢结构屋顶承板的稳定性分析

采用有限元方法对钢结构屋顶承板进行承载力的稳定性分析。计算屋顶承板结构模型的总体刚度矩阵时考虑结构的几何效应,以载荷增量法逐渐对结构增加载荷,求出载荷与结构变形的关系,并由总体刚度矩阵来判定是否为奇异矩阵,进而计算出弹性屈曲载荷。将有限元计算结果与试验结果进行比较,通过分析发现有限元分析所得屈曲载荷值与在试验中获得的屈曲载荷值很相似,误差在9%以内。     

大跨径桥梁钢桥面铺装设计

由于大跨径钢箱梁桥面铺装的使用条件、施工工艺、质量控制与要求的特殊性,因此对于特定的桥梁的桥面铺装均需作针对性的专题研究,以保证铺装设计和施工成功。总结了作者近10年对大跨径钢桥面铺装设计理论与方法设计的研究成果,包括铺装材料与结构、钢桥面铺装体系受力特性、疲劳特性、设计指标、轴载换算原则与方法、铺装体系整体优化设计方法、工程实施等技术,研究成果已在南京长江第二大桥、南京长江第三大桥、润扬长江公路大桥、苏通长江大桥和杭州湾大桥等10多座大型钢箱梁桥桥面铺装设计和铺装工程中应用。