Geometrical non-linear analysis of a simply-supported cross V-shaped folded plate roof

In this paper, the equation of the middle surface of a simply-supported cross V-shaped folded plate roof is established by means of the inclined coordinate system and generalized functions—sign function and step function. Then, the non-linear analysis for this simply-supported roof subjected to uniform load and point load is given by using the non-linear theory of shallow shell and the non-linear Galerkin's method. Finally, an illustrative example of this roof is presented. This example indicates that the largest stress of this roof is much less then that of the four pitch roof of same dimensions. Therefore, a lot of construction material could be saved by using this proposed roof.     

现浇混凝土折板屋面施工质量控制要点

结合某现浇混凝土折板屋面施工实例,归纳了其施工难点,对大跨度折板屋面立模支撑系统、高薄度混凝土浇筑等进行了阐述,实践证明该折板屋面工程完全满足设计及规范要求。     

简支平顶组合抛物面薄壳屋盖的自由振动和受迫振动的级数解

折板结构是由多块条形平板组合而成的空间结构,是一种既能承重,又可围护,用料较省,刚度较大的薄壁结构,可用作车间、仓库、车站、商店、学校、住宅、亭廊、体育场看台等工业与民用建筑的屋盖.目前折板结构建筑中绝大部分采用折叠式V形折板屋盖,比较单一,影响了推广应用范围.本文提出一种力学性能好,外观优美的平顶组合抛物面薄壳屋盖结构.借助斜坐标系和阶跃函数,建立了平顶组合抛物面薄壳屋盖的曲面方程,然后应用薄壳振动理论和变分法求得了简支平顶组合抛物面薄壳屋盖受迫振动响应的挠度和内力表达式.本文还可以解决组合抛物面薄壳屋盖的静力、自由振动和受迫振动等问题,故本文实际上包含了两种组合薄壳屋盖六个问题的解.     

勒泰中心折板钢桁架屋盖结构设计

石家庄勒泰中心空中广场屋盖采用不规则钢结构折板桁架,结构承重柱位于裙房层5～7屋顶,复杂的结构形状和支承条件造成结构受力很不均匀。介绍了结构体系选型;对比了带下部混凝土结构和不带下部混凝土结构两个模型对地震作用效应计算的差别,说明了整体分析的必要性;风致效应直接读取风洞试验计算结果进行应力和位移验算,对应3种雪荷载分别采用三种性能控制水准;对结构整体稳定极限承载力和关键节点进行了有限元分析,确保结构安全。     

拱型折板结构的塑性极限分析

本在献(1)基础上，用单元板力法求出拱型折板结构的棱边弯矩．再用上限定理与下限定理分别求出各折板塑性极限荷载的上限与下限值．     

Structural behaviour of glass folded plate curtain walls

This article is concerned with the nonlinear behaviour of glass folded plate curtain walls as an application of folded plate structures. The finite element approach was adopted for the analysis of the glass folded plate curtain walls. A plate finite element model was developed based on the nonlinear Mindlin theory. Furthermore, the model was also modified for the extension of hinges parallel to one of the global axes of the plate to simulate the case of glass folded plate curtain walls. To study the behaviour of glass folded plate curtain walls, an experimental model was built at the Structural Laboratory of Texas Tech University, USA, using aluminium plates with different connections, such as hinged or welded, and with different boundary conditions. The model, with different setups, was tested under distributed loads using vacuum machine. The results obtained from the experimental study were compared with the corresponding finite element results and conclusions were drawn.     

Analytical solution to flexural responses of annular sector thin-plates

A novel analytical solution is presented for the flexural response of annular sector thin-plates. An exact solution has been developed in the series form including trigonometric and exponential functions in the polar coordinate system for annular sector plates subjected to uniform loading. The salient feature of the solution development includes the derivation of a closed-form solution for the fourth-order partial differential equation governing plate deflections in the polar coordinate system.     

坡屋面混凝土点振法施工浅析

针对坡屋面在现浇过程中产生的问题，结合施工管理与实践，总结出一种新的施工方法——混凝土点振法，论述了点振法施工坡屋面混凝土及点振法对模板和钢筋施工的要求，采用点振法施工坡屋面混凝土，可达到预防屋面渗漏水的效果。     

Analytical solution for tunnelling-induced ground movement in clays

Elastic solutions are presented to predict the tunnelling-induced undrained ground movements for shallow and deep circular tunnels in soft ground, by imposing the oval-shaped ground deformation pattern as the boundary condition of the displacement around the tunnel opening. The gap parameter is used to describe the displacement at the opening. The difference between uniform radial and oval-shaped ground deformation patterns on ground deformations is investigated and different definitions for ground loss are discussed. The applicability of the proposed analytical solutions is checked with five case studies. Generally good agreement of the predicted ground deformations can be seen with field observations for tunnels in uniform clay.     

饱和黏性土地基中现浇大直径管桩水平振动响应解析解

基于经典的平面应变假定,将土体假设为若干个相互独立的薄层,对饱和土地基中现浇大直径管桩水平振动频域特性进行了理论研究。首先通过引入势函数对土体动力固结方程解耦,采用Laplace变换和分离变量的方法求得了桩周土及桩芯土频域响应解析解,进而利用桩土完全耦合的条件得到桩振动响应解,给出了桩顶复阻抗解析表达式。将本文解完全退化到实心桩的解与已有理论解对比,验证了本文解的合理性并阐明两解的区别。通过参数分析,得到了桩长以及桩半径等参数对复阻抗特性影响的规律。     

楼顶广告牌结构基本自振周期计算方法研究

为精确得到楼顶广告牌结构的基本自振周期,采用结构分析软件SAP2000针对楼顶广告牌自身钢结构、大楼结构、楼顶广告牌钢结构与下部钢筋混凝土大楼整体结构分别进行了广告牌结构基本自振周期的计算,结果表明:下部钢筋混凝土结构对楼顶广告牌风荷载计算有着较大的影响,整体结构的基本自振周期远大于单独钢结构基本自振周期,而与大楼结构基本自振周期相近,在计算楼顶广告牌结构风荷载时应综合考虑下部房屋结构的影响。分析结果对今后楼顶广告牌的设计和检测计算具有参考价值。     

弹性地基上自由层合圆板弯曲问题的解析解

从三维弹性力学基本方程出发 ,建立了弹性地基上周边自由的横观各向同性层合圆板轴对称弯曲问题的状态方程 ,并将板面的法向载荷展成傅里叶 -贝塞尔级数 ,从而给出问题的解析解。此解满足弹性力学全部方程 ,计及了所有独立的弹性常数 ,并满足层间连续性条件。     

大跨悬挑屋盖风振系数研究

针对荷载规范中对大跨悬挑屋盖结构风振系数计算的不足,利用时程分析法,在有限元建模的基础上,直接采用风洞试验数据,计算了某大跨悬挑屋盖结构的荷载风振系数和位移风振系数,研究了其随风向角的变化规律,并讨论了不同风向角下结构参数的影响。     

大悬挑屋盖结构采用筒式粘弹性阻尼器的风振控制应用研究

合肥体育中心综合体育馆为大悬挑钢网架屋盖结构,悬挑28.23m.该屋盖结构悬挑跨度大,造型复杂,且悬挑部分上、下表面均受到风的作用,原设计方案的悬挑自由端竖向位移超出了规范的规定.为有效抑制风振响应、改善结构抗振性能,采用筒式粘弹性阻尼器对其进行风振控制.根据消能支撑的风振控制力、等效刚度、等效耗能因子及结构动力特性,在大悬挑钢屋盖结构的关键部位设置附加的消能支撑.研究和实践表明,设置消能支撑后,明显减小了风振的竖向位移反应,其强度和刚度均满足规范要求,取得了很好的社会效益和经济效益.     

Analytical solution for steady-state groundwater inflow into a drained circular tunnel in a semi-infinite aquifer: A revisit

This study deals with the comparison of existing analytical solutions for the steady-state groundwater inflow into a drained circular tunnel in a semi-infinite aquifer. Two different boundary conditions (one for zero water pressure and the other for a constant total head) along the tunnel circumference, used in the existing solutions, are mentioned. Simple closed-form analytical solutions are re-derived within a common theoretical framework for two different boundary conditions by using the conformal mapping technique. The water inflow predictions are compared to investigate the difference among the solutions. The correct use of the boundary condition along the tunnel circumference in a shallow drained circular tunnel is emphasized.     

焦炉基础顶板预埋管施工工艺探讨

结合自身多年的施工经验,对焦炉基础顶板预埋管施工工艺进行了分析和探讨,介绍了采用管座及钢管固定体系的工艺特点、原理,着重阐述了该技术施工流程及操作要点,为今后焦炉基础顶板施工提供了借鉴。     

厦门理工学院体育馆压型钢板屋面的加固修复

体育馆压型钢板部分屋顶被台风破坏,在认证为不可抗力破坏后,分析破坏原因,探讨研究原设计的薄弱环节,并有针对性的提出修复补强方案,根据调整的设计方案对破坏后的屋顶修复进行过程控制,保证工程的质量。     

砂质海床中锚板基础水平振动动力特性研究

基于埋置在耦合海水–海床半空间中刚性、无重量圆盘基础的水平振动动力阻抗[1],简单讨论了海洋工程中常用的承受竖向拉力的、有自重的锚板基础在水平波浪动荷载下的振动情况。给出了计算深埋锚板基础在发生共振时的共振频率和放大系数的简化计算公式。最后通过采用实际的海床砂土参数及锚板参数,得出了只要锚板的厚径比满足一定的要求,深埋锚板基础一般不会发生共振的结论。对于真实的深埋锚板基础,这个厚径比要求一般是较容易满足的。此外,锚板水平位移对低频海洋波浪水平荷载的频率变化并不敏感,最大水平位移发生在频率为0即静载情况下。本文结论对于理解海洋工程中锚板基础在水平波浪荷载作用下的振动特性有所帮助。     

银川机场航站楼钢结构风振分析

对银川机场扩建工程中的航站楼主楼钢结构的风致振动效应进行了分析.简述了该建筑风洞试验的风压分布特点.采用基于里兹向量的振型分解频域法进行结构风振计算.分析了该结构的风振效应的数值和分布特点,发现平均风荷载较大区域(靠近来流区域)的风振系数相对较小,而平均风荷载较小区域(远离来流区域)的风振系数反而大.结构的平均风效应和脉动风效应并不完全符合分布相似的特点,因此在设计时简单地采用统一风振系数的做法,将不能有效反映结构的实际风致振动效应.     

计算肋形板自振频率的能量法

应用能量原理导出肋形板自振频率计算式,针对工程中肋形板不同的边界约束状况,给出振型试函数各种形式,指出该方法既适用于不同纵、横梁布置的板,也适用于板边各种支承情况,与有限单元法相比,无需计算机程序,计算过程简单易行。