拉索预应力空间网格结构的全过程设计

将拉索预应力空间网格结构中产生预应力的本质归纳为拉索的初始缺陷长度，并从初始缺陷长度的角度出发，提出了拉索预应力空间网格结构的分析设计方法。     

预应力混凝土梁施工阶段数值模拟

采用有限元分析软件ANSYS对先张法预应力混凝土简支梁施工阶段进行数值模拟分析。结果表明,ANSYS有限元分析计算值与理论值吻合较好,为预应力混凝土结构的分析提供了较好的途径和方法。教学实践表明:有限元数值模拟分析补充、丰富了教学内容,对常规教学方式提供一种思路。     

鄄城黄河桥引桥50m折线配筋预应力砼T梁施工

德商高速公路鄄城黄河公路大桥引桥50m折线配筋预应力砼T梁是目前国内建设规模最大的折线配筋先张梁项目,它采用先张梁较后张梁优势明显,先张梁完全避免了后张法中可能出现的堵孔、压浆不密实、预应力失控等影响结构质量与耐久性的问题.鄄域黄河桥的50m折线配筋先张法T梁的建设也为后来的折线配筋先张法项目提供了大量的试验数据和宝贵的施工经验.     

预应力混凝土连续箱梁有限元损伤分析(英文)

为了确定预应力混凝土箱粱的极限承载能力,进行了预应力混凝土连续箱梁的破坏性试验,提出一种有限元损伤分析方法模拟箱梁结构行为.基于实体退化壳单元对箱梁进行模拟,并考虑了结构材料的非线性效应.由于预应力混凝土箱梁中通常存在大量曲线预应力钢筋,提出一种组合单元,并用该单元模拟箱梁中的预应力钢筋,该方法可使结构分析时单元数量大大降低.试验结果和理论分析对比表明:提出的方法能够有效地用于预应力混凝土连续箱梁的破坏性试验计算分析中;研究的旧桥依然存在较大的极限承载能力.     

有粘结预应力FRP筋混凝土梁受弯有限元模拟

采用有限元软件ABAQUS对预应力FRP筋混凝土梁受弯性能进行模拟。通过降温法施加预应力,忽略预应力筋与混凝土之间的粘结滑移。在收敛度差调整到3%、线性受拉损伤值dt的峰值取为0.9时,模拟结果与他人的试验结果比较基本吻合。     

预应力CFRP加固法在桥梁工程中的应用现状及展望

预应力CFRP加固法较非预应力CFRP加固法更能发挥CFRP高强的材料性能,具有更加广阔的应用前景。本文就预应力CFRP加固法的材料特点、预应力施加工艺、应用进展以及国内外的研究现状作了总结,并展望了此方法的未来研究方向。     

提高空心板梁桥横向整体性与刚度的方法研究

利用有限元程序MIDASCivil建立了装配式预应力混凝土空心板桥整体计算模型并进行计算,通过对比分析装配式预应力板桥在重做铺装、粘贴钢板和施加横向预应力的荷载横向分布影响线降低幅度、变化趋势,其中,着重分析了施加横向预应力之后的加固效果。有限元模型分析的结果表明,施加横向预应力效果最好,可达到治本效果。     

FRP加固在役混凝土柱轴压试验方法

为研究FRP(fiber reinforced plastics)加固在役混凝土柱轴压性能的试验方法,采用后张预应力法对混凝土柱施加初始应力,然后采用附加刚性千斤顶加载法进行模拟FRP加固混凝土柱轴压加载试验,得到应力-应变全曲线。研究结果表明,该试验方法能较好地实现FRP加固在役混凝土柱轴心受压试验。     

先张法预应力波型板桩截面分析与力学试验

分析了先张法预应力混凝土波型板桩自身截面原形的力学性能,克服了以往将波形板桩截面等效简化为工字型截面的计算过程复杂繁琐且易产生误差的缺点,新的计算分析方法较以往等效截面计算方法更加科学合理,过程简单清晰,结果误差小。同时结合理论分析进行波型板桩抗弯和抗剪力学试验,对比理论计算结果与力学试验数据,两者吻合较好,验证了理论分析方法合理可靠。     

预应力管桩（PHC）钢筋应力计埋设与计算实例

预应力管桩的桩身轴向力测试采用桩端封闭管桩,将钢筋应力计与钢筋焊接并置于管桩空腹中,随即浇筑砼封填,并利用沉桩的最后锤击振动使封填的砼密实。该方法施工方便、操作简单、应力计成活率高,每级加载微应变增量稳定,轴力变化清晰。     

预应力锚索在高坝洲电站蜗壳中的应用

介绍了预应力锚索在高坝洲水电站蜗壳中的应用,运用有限元方法进行了应力分析、强度和限裂验算,指出了预应力锚索加固的优点.     

Initial pre-stress finding procedure and structural performance research for Levy cable dome based on linear adjustment theory

The cable-strut structural system is statically and kinematically indeterminate. The initial pre-stress is a key factor for determining the shape and load carrying capacity. A new numerical algorithm is presented herein for the initial pre-stress finding procedure of complete cable-strut assembly. This method is based on the linear adjustment theory and does not take into account the material behavior. By using this method,the initial pre-stress of the multi self-stress modes can be found easily and the cal-culation process is simplified and efficient also. Finally,the initial pre-stress and structural performances of a particular Levy cable dome are analyzed comprehensively. The algorithm has proven to be efficient and correct,and the numerical results are valuable for practical design of Levy cable dome.     

非预应力大跨度混凝土空心现浇楼板设计

大跨度结构应用范围越来越广泛,而且随着建筑技术的发展和建筑材料的更新,实现大跨度的手段也越来越多。除了预应力、钢结构、网架等通常结构以外,探讨一种普通材质为主的现浇空心板结构。结合实例,具体阐述计算及构造要点。     

Sensitivity analyses of cables to suspen-dome structural system

The construction of the cables is a key step for erecting suspen-dome structures. In practical engineering, it is difficult to ensure that the designed pre-stresses of cables have been exactly introduced into the structures in the site; so it is necessary to evaluate the influence of the variation of the pre-stresses on the structural behavior. In the present work, an orthogonal design method was employed to investigate the pre-stressed cables'sensitivity to the suspen-dome system. The investigation was concentrated on a Kiewitt suspen-dome. Parametric studies were carried out to study the sensitivity of the structure's static behavior, dynamic behavior, and buckling loads when the pre-stresses in the cables varied. The investigation indicated that suspen-dome structures are sensitive to the pre-stresses in all cables; and that the sensitivity depended on the location of the cables and the kind of structural behavior. Useful suggestions are given at the end of the paper.     

Sensitivity analyses of cables to suspen-dome structural system

The construction of the cables is a key step for erecting suspen-dome structures. In practical engineering, it is difficult to ensure that the designed pre-stresses of cables have been exactly introduced into the structures in the site; so it is necessary to evaluate the influence of the variation of the pre-stresses on the structural behavior. In the present work, an orthogonal design method was employed to investigate the pre-stressed cables' sensitivity to the suspen-dome system. The investigation was concentrated on a Kiewitt suspen-dome. Parametric studies were carried out to study the sensitivity of the structure's static behavior, dynamic behavior, and buckling loads when the pre-stresses in the cables varied. The investigation indicated that suspen-dome structures are sensitive to the pre-stresses in all cables; and that the sensitivity depended on the location of the cables and the kind of structural behavior. Useful suggestions are given at the end of the paper.     

基于神经网络的体外预应力筋极限应力的预测

鉴于影响体外预应力筋极限应力的因素较多,采用BP和RBF两种人工神经网络模拟方法进行体外预应力筋极限应力进行预测。通过和试验数据比较分析,预测结果与试验结果的相对误差均在10%以内,满足工程需要,因此,采用神经网络预测体外预应力筋极限应力是可行的。     

新技术在闸墩预应力钢筋施工中的运用

在苏丹麦洛维大坝工程溢流坝闸墩预应力钢筋施工中,采用新型螺纹钢筋、新型千斤顶、新型液压油泵、半球形紧固螺母、法国Alstom注浆泵以及国际工程施工常用的伸长值反算实际张拉力、快速注浆阀门等新工艺和新技术,确保了工程施工质量,提高了工作效率。这些新技术可为同类工程借签。     

Experimental study on the construction shape-forming process and static behaviour of a double strut cable dome

A double strut cable dome structural system was presented to improve the mechanical behaviour of a cable dome. This structure has good stability and is convenient to construct. To investigate its construction method and static performance, a structural model with a 6-m diameter was designed. From the nodal equilibrium equation, the calculation formulas for the prestress distribution with self-weight considered were deduced. Two types of construction methods, namely, assembling at high altitude and integral lifting, were adopted in the shape-forming process of the double strut cable dome, monitoring the internal force of the cable-strut components and the structural deformation. According to loading tests under full-span load and half-span load, the static behaviour of the structure was obtained and compared with the results from finite element analysis. Using the formulas deduced in this paper, the actual initial prestress considering self-weight for a double strut cable dome can be obtained accurately. This structure was suitable for tensioning the outer diagonal cables to apply prestress. Combined with the construction method for integral lifting, the difficulty and workload of the construction process can clearly be reduced, making the structure favourable for engineering application. Under an external load, the internal force of the ridge cables and inner diagonal cables decreases and the internal force of the other components increases. The results of the model tests were in good agreement with those of the finite element analysis.