多维地震动作用下曲线连续桥梁地震易损性研究

基于OpenSees有限元平台建立三类曲线连续梁桥,对算例桥梁进行三向平动地震动作用下的增量动力分析,并采用概率性地震需求分析方法绘制三类曲线连续桥梁关键构件的地震易损性曲线。结果表明在地震作用下,曲率半径小的单弯曲线连续梁桥比曲率半径大的单弯曲线连续梁桥损伤概率稍大;S型曲线连续梁桥相对于单弯曲线连续梁桥在桥墩横桥向损伤概率更大,且在多遇地震地震动加速度峰值(PGA=0.2g)以内,支座损伤概率较大。     

用钢筋弯曲机制作圆弧钢筋

市场销售的钢筋弯曲机,只能进行折角、弯钩等作业,而工业厂房中设备孔洞及圆弧形梁板所需的圆弧钢筋,一般用手工弯制,劳动强度大,功效低,制成的圆弧筋尺寸不准确。若在钢筋弯曲机上     

工字形截面连续梁-柱弹塑性弯扭屈曲分析

本文把有限积分法和有限差分法相结合,提出了一种新的数值计算方法,对工字形截面连续梁-柱弯扭屈曲弹塑性问题进行了分析。与有限差分法相比,该法计算精度高,节省贮存单元,同时可以方便地处理各种复杂的杆端条件。此外,文中还给出了连续梁-柱中杆件出平面长细比的限值,并提出了三跨连续梁-柱弯扭屈曲临界节点弯矩的近似计算公式。     

曲线连续梁桥单支座预偏心设计研究

本文以桥梁中墩采用独柱式点支承的曲线连续梁桥为例，介绍了如何通过设置不同支座的预偏心，来调整梁内扭矩的分布，达到改善弯扭耦合作用、优化曲线连续梁结构受力的目的。     

缓黏结预应力混凝土连续梁试验裂缝间距统计分析

基于缓黏结预应力混凝土两跨连续梁的受弯试验研究,将4根缓黏结预应力混凝土两跨连续梁分为30 d龄期与90 d龄期两组进行加载,并与无黏结预应力混凝土连续梁和有黏结预应力混凝土连续梁进行对比。通过对裂缝间距进行统计分析,得出结论:不同龄期缓黏结预应力混凝土连续梁其裂缝间距不仅基本相同呈现正态分布,而且不同龄期分别表现出与无黏结预应力混凝土构件和有黏结预应力混凝土构件相同的受力特性。     

翼缘板粘贴CFRP加固连续梁负弯矩的试验研究

通过6根连续梁研究了用CFRP加固T形截面翼缘板改善钢筋混凝土连续梁负弯矩的受弯性能。研究结果表明,T形截面翼缘板粘贴CFRP可以提高连续梁负弯矩的开裂荷载、极限荷载,当粘贴层数≥3时,连续梁由弯曲破坏转变为剪切破坏,在4倍翼板厚度范围内粘贴是有效可行的。粘贴CFRP层数相同时,翼板厚对结构的极限荷载无影响。     

北京市西厢工程菜户营立交独柱支承预应力弯箱连续梁桥设计与分析

本文简要介绍了北京市西厢工程菜户营立交中独柱支承预应力混凝土弯箱连续梁桥在设计上的一些特点和采用的新技术、新工艺,对工程设计中遇到的一些问题及解决方法进行了较详细的论述。在结构分析方面,探讨了预应力弯箱梁桥的空间计算、力学模型的建立及抗扭刚度的计算方法,提出了平面曲线连续梁桥独柱支承合理偏心的计算方法。     

国外期刊论文简介

JournalofConstructionalSteelResearch弯剪共同作用下的连续组合梁的极限强度研究Liang,QingQuan ;Uy,Brian(澳大利亚 )连续梁中的混凝土楼板对钢梁的竖向抗剪强度是有所贡献的 ,但现有的设计规范中并没有考虑这一有利因素 ,因此这样的设计方法偏于保守。本文用有限元方法研究了组合连续梁在弯剪共同作用下的极限强度。作者提出了一个三维有限元模型 ,可以模拟连续组合梁的材料、几何非线性。通过试验对有限元模型进行了验证 ,随后研究了混凝土板对梁竖向抗剪能力的影响 ,通过改变组合梁的弯剪比值来分析连续组合梁在弯剪相互作用下的…     

跨高速公路特大桥连续粱施工安全管理

跨高速公路现浇连续梁施工工艺复杂、影响面广、工期紧、安全防护难度大,是铁路施工安全管理难点之一。本文主要以石武客专河南段漯驻特大桥跨漯平高速40m＋64m＋40m现浇连续梁施工为例,探讨铁路客运专线跨高速公路连续梁施工的安全管理。     

高强钢筋混凝土连续梁受弯性能的试验研究和有限元分析

共进行了2根采用HRB500级高强钢筋和1根HRB335普通钢筋混凝土连续梁的受弯性能试验研究及有限元分析。研究结果表明:高强钢筋混凝土连续梁在裂缝发展规律、截面应变分布、塑性铰出铰顺序和破坏形态等方面与普通钢筋混凝土连续梁基本一致。但高强钢筋混凝土连续梁的跨中屈服荷载、中支座屈服荷载和极限荷载均较普通钢筋混凝土连续梁明显提高,分别提高28.7%、22.8%和30%;构件延性有所提高,提高幅度为8.1%。有限元分析结果与试验结果吻合较好,精度符合工程精度要求。     

Ideelle Biegedrillknicklasten von Kreisbogenbindern aus Brettschichtholz mit gebundener Kippachse

Bifurcation loads of circular curved beams of glued‐laminated timber with continuous lateral support. On the basis of the energy method in connection with the static stability criterion a specific finite element formulation is developed with which bifurcation loads of curved beams of glued‐laminated timber can be determined easily. Because of the small numeric effort this procedure is excellently suitable for parameter studies. Extensive single investigations on the basis of two or three‐dimensional finite element models become normally superfluous. In the last part of the paper the results of a study are presented at circular curved beams of glued‐laminated timber. On condition of a continuous lateral support at the upper chord bifurcation loads are determined and presented graphically.     

圆心角对预应力砼曲线连续梁弹塑性力学的影响

圆心角是影响曲线梁力学行为的重要因素.为揭示圆心角对预应力混凝土曲线连续梁弹塑性力学行为的影响规律,笔者建立的预应力混凝土曲线梁理论模型及程序,用计算机模拟一系列不同圆心角情况下的预应力混凝土曲线连续梁,研究了在弹性和塑性阶段预应力混凝土曲线连续梁的内力、变形及支座反力随圆心角的变化规律.得出在弹性工作阶段当α0≤0.25时,对于剪力和弯矩可按直线梁计算的结论.     

Numerical study on horizontally curved steel-concrete composite beams subjected to hogging moment

The horizontally curved continuous composite steel-concrete beams, for instance, curved continuous composite bridges, have excellent qualities, such as quick construction, good seismic performance, saving construction formwork and convenience in spatial arrangement etc. At present, the application research of this kind of structures is becoming more of a concern, but very few studies have been conducted to study the mechanical performance of composite beams subjected to combined hogging (negative) bending and torsion. The purpose of the present study is to investigate the effects of curvatures on both elastic and inelastic behaviours of curved continuous steel-concrete composite beams in the interior support regions. Based on the experimental observations in a straight composite beam, a three-dimensional FE model capable of analysing the composite beams subjected to negative bending moment is built. Further numerical studies on curved composite beams with different curvatures are performed in this study. Strength and load carrying capacity, sectional strain distribution and movement of composite neutral axis before and after cracking, as well as the strain results of longitudinal reinforcing bars are investigated. Besides, the interaction equation for ultimate bending and torsional moments is proposed.     

施工误差影响下的超长空间预应力束摩阻系数识别研究

预应力构件中的超长空间曲线束其预应力损失通常较大,而施工误差的存在又会增加预应力损失而降低有效预应力,对结构通常会带来不利影响。因此,在预应力结构分析中,有必要考虑施工误差的影响,对超长空间曲线束的预应力损失进行实测并对计算预应力损失的相关系数进行修正,以此考察实际预应力损失对成桥结构的影响。本文则以某连续梁桥的底板通长束为例,通过现场实测钢绞线应力以及理论分析来确定对预应力损失影响最大的摩阻系数值,再依此进行结构有限元模型修正,研究由施工误差导致的预应力损失对成桥结构的影响。     

隔震曲线桥梁碰撞研究

目前,铅芯橡胶隔震支座已应用于曲线桥梁,由于采用铅芯橡胶支座,地震作用下梁体位移增大,相邻梁体间容易产生碰撞。国内外对于曲线桥梁碰撞的研究相对甚少,本文以一座三联曲线桥梁为研究对象,用非线性时程分析确定曲线桥梁最不利地震输入角度,在此基础上,用本文确定的最不利地震输入角度讨论了曲线桥梁梁间碰撞响应对梁及桥墩的影响。计算结果表明,曲线桥梁采用隔震支座后,可以明显消耗碰撞过程中产生的能量,碰撞对桥墩影响不大,但是瞬时的碰撞对梁轴力影响很大。     

栓钉连接件时变受剪承载力对组合梁施工阶段受力性能的影响

为了对钢-混凝土组合梁施工阶段的受力性能进行准确分析,针对我国常用的隔板式组合梁,通过推出试验研究栓钉连接件受剪承载力随混凝土龄期的变化规律,采用ANSYS有限元分析软件分析栓钉连接件时变受剪承载力对某连续曲线组合梁施工阶段受力性能的影响。分析结果表明：在混凝土龄期很短时栓钉连接件就具有一定的受剪承载力和抗剪刚度,且早期增长快,后期增长慢;混凝土板分段浇筑时组合梁的应力和变形随浇筑时间间隔的增加逐渐减小,在本文实例中,与不考虑浇筑过程中混凝土与钢梁的组合作用时相比,浇筑时间间隔为6 h的组合梁径向变形减小26.5%;与考虑28 d龄期混凝土与钢梁的组合作用时相比,浇筑时间间隔为3 d的组合梁切向应力增大14.2%。因此,当组合梁混凝土板浇筑时间间隔在6 h至3 d之内时,均应采用栓钉连接件的时变受剪承载力来分析浇筑过程中混凝土与钢梁的时变组合作用对组合梁施工阶段受力性能的影响。     

圆形孔蜂窝钢梁试验研究

通过对圆形孔和六边形孔两种孔形的蜂窝钢梁试验研究,揭示了圆形孔蜂窝钢梁的受力特性,对比分析了两种孔形的梁的受力性能,并将圆形孔蜂窝梁的试验结果与理论简化计算结果进行了对比分析。     

Experimental study on curved composite beams subjected to combined flexure and torsion

There are situations in which a composite steel–concrete beam is subjected to torsion, such as members that are curved in plan or straight edge beams. The concrete slab and steel beam contribute to the torsional strength and stiffness of a composite steel–concrete beam, but this composite action is usually ignored in design codes of practice, which leads to conservative designs. Therefore, this paper investigates the ultimate strength of curved in place composite steel–concrete beams. Eight curved in plan composite steel–concrete beams have been tested under a single applied load at mid-span. Partial shear connection has also been considered in these tests. The composite steel–concrete beams have been designed with different span/radius of curvature ratios. This paper further supports the view that, in the presence of flexure, there will be an increase in the torsional moment capacity, but the flexural moment capacity does not greatly increase in the presence of torsion. A model has also been presented to represent the bending–torsion interaction for curved in plan composite steel–concrete beams with full and partial shear connection.     

Nonlinear elastic analysis of composite beams curved in-plan

A novel 3D elastic total Lagrangian formulation is developed for the numerical analysis of steel–concrete composite beams which are curved in-plan. Geometric nonlinearities are considered in the derivation of the strain expressions, and the partial interaction at the interface in the tangential direction as well as in the radial direction due to flexible shear connectors is incorporated in the unique proposed formulation, which is derived from considerations of fundamental engineering mechanics. Examples are presented to illustrate the effects of initial curvature, geometric nonlinearity and partial interaction on the behaviour of composite curved beams, which are compared with those based on more sophisticated but computationally less efficient ABAQUS shell element models and experiments reported in the literature. The results demonstrate that the developed formulation is accurate and effective in capturing the behaviour of composite beams curved in-plan, providing a highly efficient finite element.     

广西体育中心主体育场异形混凝土构件施工技术

广西体育中心主体育场工程为框架剪力墙结构,结构复杂,异形构件多,体量大,斜柱、曲梁尤具代表性,其造型、体量国内罕见.其测量定位、高架支撑、模板、钢筋、混凝土等工程施工难度大,通过制定科学合理的专项施工方案,采取切实可行的施工技术措施,最终按期保质完成了斜柱曲梁的施工.其成品质量达到设计及施工规范要求.