灌注桩竖向承载力静载试验与有限元模拟

在某变电站工程5根灌注桩进行竖向承载力静载试验的基础上,采用通用有限元软件ABAQUS对静载试验进行数值模拟,给出了建模方法和受力模拟过程,得到桩的Q-s曲线和沉降规律。研究发现土体的弹塑性关系中的弹性模量和桩土摩擦系数对分析结果有着重要影响。通过与试验结果进行对比,对该工程的有限元模拟中土弹性模量的选取和桩土摩擦系数的确定进行了总结。本文的有限元模型和方法能够有效地模拟灌注桩静载试验,可以对以后的工程设计和研究有一定的借鉴作用。     

静载试验梁式反力系统设计方法研究

静载试验由于结果准确被广泛的应用于工程实践中,介绍了现有反力系统的主要种类与优劣,为改进静载试验梁式反力系统设计方法,基于欧拉–伯努利梁理论提出了梁式反力系统的设计方法,为梁式反力系统的设计与施工提供了有力依据。通过大型有限元软件Abaqus,采用由须寅、龙驭球提出的广义协调矩形膜元,模拟了梁在受静载作用时的线弹性变形与非线性变形,分析了反力作用下梁在线弹性阶段与非线性阶段的受力情况以及梁内钢筋的应力应变情况。通过有限元模拟静载试验中的逐级加载过程并结合工程实测数据进行对比,进一步确保了静载试验梁式反力系统设计方法的准确性、有效性与安全性。     

基于静载试验与仿真分析的旧桥承载力评估

通过对店埠河桥现场静载试验,介绍一种基于静载试验结果和有限元数值仿真分析的旧桥承载力评定方法,通过实测值与理论值比较说明静载试验结果可以很好地表现出结构工作性能和使用性能。     

马道静载试验与有限元分析

本文以某大剧院多功能厅钢桁架结构马道为背景,对该马道进行了静载试验研究。由于是新建结构,对其正常使用存在不确定性,所以用单调加载静力试验来研究其承载力和稳定性。通过静载试验得到马道最大跨主要受力杆件的应变大小以及最大跨挠度大小等重要数据,然后使用有限元软件ABAQUS进行了建模分析,由此也进一步的验证出检测数据的可靠性。有了这一分析过程也将为现实工程结构静载试验检测鉴定提供参考。     

浅析30m简支梁桥检测技术

本文依托某桥梁检测工程实际,论述述了简支梁桥检测的主要内容,包括外观检测、静载试验和动载试验。外观检测涵盖上部结构、下部结构、桥面系及混凝土强度、钢筋保护层等无损检测;桥梁动静载试验涉及有限元模型建立、加载方案制定和实施、试验数据采集和分析等过程。     

现浇混凝土楼板荷载试验及数值仿真

研究楼板结构在静载作用下安全使用性能的评估方法,针对工业厂房楼板结构跨度长、荷载大等特点,介绍楼板结构现场静载试验的基本内容和方法。以贵州省都匀市某厂房为实例,采用现场注水加载试验及有限元技术,对楼板结构的安全使用性能进行分析与评估,结果表明现场静载试验与有限元分析方法相结合,可为楼板结构的安全评估和加固等提供科学依据。     

长系杆钢管混凝土拱桥静载试验

静载试验是验证桥梁工程结构安全的重要方法,曹娥江袍江大桥为5跨飞燕式钢管混凝土拱桥,大桥建成后通过静载试验对袍江大桥整体结构的安全承载能力和使用条件做出了判断。静载试验测定了结构关键截面的挠度和应变,并建立了桥梁的有限元模型,对不同加载工况进行计算分析,将实际测试值与理论值进行比较。     

抗拔组合式锚板静载反力系统在工程中的应用

传统的基桩静载试验已经不能满足实际工程需要,且试验费时费力,存在着不小的安全隐患。抗拔组合式锚板静载反力系统主要通过锚板、钢箱梁及高强度钢棒连接,可单独用作单桩抗拔静载试验,还可结合锚桩及一定量的配重用作大吨位单桩竖向抗压静载试验。本文基于有限元对锚板装置的初步验算,结合现场试验的验证,从而模拟设计了该反力系统在最大试验荷载下的实际使用工况。该系统通过机械连接代替传统的焊接,解决了在高应力作用下出现开裂的问题,进一步优化该系统,使安装拆卸简单,运输方便,大大节省了工期并降低了施工成本。     

碳纤维布加固钢梁拼接节点的试验研究和有限元分析

通过碳纤维布加固钢梁高强螺栓拼接节点的静载试验,考察了影响加固效果的主要因素和钢梁的破坏形态。运用ANSYS有限元分析软件,建立考虑接触摩擦与预紧力的钢梁螺栓拼接节点有限元分析模型,并进行数值模拟,分析碳纤维布加固的螺栓节点对钢梁的屈服荷载和刚度的影响。有限元分析结果和试验结果均表明加固措施的有效性。     

高荷载条件下桩基静载试验反力装置研究

埃塞俄比亚亚的斯亚贝巴市某桥梁工程的桩基竖向静载试验设计荷载较高,现有桩基静载试验中反力装置局部存在强度应力的安全问题。针对该实际问题,在材料短缺的情况下,本文设计了一套能满足桩基竖向静载的新反力装置,该装置通过贝雷支架与工字钢、钢管钢筋混凝土组合焊接成整体,并采用Midas有限元软件对桩基竖向静载条件下的新反力装置进行计算与分析。结果表明,新反力装置满足要求,并成功地应用于实际工程,解决了桩基静载试验的技术安全问题。     

Evaluation of a steel railway bridge for dynamic and seismic loads

In this study, dynamic and seismic assessment of a railway bridge system with four discrete spans giving service on a double track railway line and located in an earthquake-prone region in Turkey is presented. A three-dimensional computer model of the bridge was generated using a commercial general finite element analysis software. Field measurements such as static and dynamic tests as well as material tests were conducted on the bridge system. Validation of the finite element model was performed based on the results of these tests. The calibrated 3D model of the bridge structure was then used for necessary calculations regarding structural assessment and evaluation according to train loads as well as seismic loads. Additional members were proposed to transmit seismic loads to supports. The fourth span, which had a permanent imperfection due to truck collision was studied in detail. Results have shown that due to excessive amount of capacity loss, the only choice was to write off the fourth span.     

某在役高架钢箱梁桥的安全性评定及相关问题探讨

在实际桥梁工程检测中,往往因为周围环境条件的制约,不能获得原计划中的所有测试数据或是所获得数据准确性受到行车荷载的影响.针对这两个问题,以某在役钢箱梁桥的损伤检测和安全性评定为例,探讨解决这两种问题的途径.首先介绍了该钢箱梁桥跨的表现检测和无损探伤,之后对该桥进行静动载试验,以获得桥梁在试验荷载下的静动力响应.为了与试验结果对比,还用两种方法建立钢箱梁桥跨的有限元模型,在对比不同方法计算准确度的基础上获得设计以及试验荷载下桥梁静力响应以及模态参数的计算值;最后,探讨静载测试数据的扩充办法,并对试验荷载作用下的计算模型进行了修正,通过模拟试验过程中某车道行车荷载对计算结果的影响,从而成功解决了前述的两种问题,实现了该钢箱梁跨的安全评定.     

孟加拉国36.6m跨贝雷桥静载和疲劳试验

孟加拉国36.6m跨贝雷桥是1座在HD200型贝雷桥基础上改进的简支装配式公路钢桥,通过静载和疲劳试验研究该桥的承载能力和疲劳寿命。试验结果表明:在设计活荷载作用下,该桥挠跨比为1/830,横梁、上下弦杆、斜竖杆和桥面板的应力均满足规范要求;在1.5倍设计活荷载作用下,各杆件单元应力均未超过钢材的屈服强度。该桥下弦杆销钉在工作应力幅作用下,疲劳寿命可以达到200万次。孟加拉国36.6m跨贝雷桥的承载能力和疲劳寿命能够满足使用要求。     

Versuche an genieteten Brückenlängsträgern – Statisches Verhalten,Ermüdungsfestigkeit und Rissausbreitung

Tests on riveted bridge stringers – behaviour under static loads, fatigue strength and crack propagation. The assessment of the load‐carrying capacity and of the remaining fatigue life of existing railway and road bridges has gained an increasingly significant role over the last years. Thus, the problem of determining adequate strength values of riveted members of older steel bridges once again arose during the elaboration of the ONR 24008 specification. In the course of a research project initiated by the Austrian Federal Railways (ÖBB), static and fatigue tests were carried out on riveted members taken from a demolished railway bridge in Salzburg. The results of these tests gave further insight into the load carrying behaviour of built‐up riveted members, particulaly the progagation of fatigue cracks.     

钢筋混凝土肋拱桥静动载试验与评估

以一座3跨100m上承式钢筋混凝土肋拱桥为例,对其进行了静动载试验和计算评估。静载试验中,测试并分析了主拱圈和桥面板控制截面的挠度和应力。动载试验中,测试并分析了该桥的自振特性以及行车激振下的冲击作用。根据实测拱轴线坐标,考虑温度、混凝土收缩徐变等因素,对3跨连拱进行仿真分析。比较分析试验和仿真计算结果表明:该桥在承载能力极限状态下,主拱圈拱脚附近截面承载能力不足,桥面板承载能力能满足设计要求;在正常使用极限状态下,主拱圈和桥面板具有足够的强度和刚度;结构整体受力处于弹性状态,具有良好的动力性能;静动载试验和仿真计算相结合的评估方法可以准确而全面地评定结构性能。     

珠江大桥西桥动静载试验研究

本文介绍了对广州市内环路广佛出口放射线珠江大桥西桥进行的动静载试验的荷载试验的内容、检测方法、分析总结和荷载试验的结果；并依据试验结果对该桥的成桥质量和动静载工作状态作出了合理的评价。     

Fatigue assessment and strengthening measures to upgrade a steel railway bridge

The present paper deals with the experimental and analytical study of a 19th century riveted steel truss railway bridge to assess its current condition and remaining time of life. The analysis includes static and dynamic field measurements and laboratory tests. The evaluation of the capacity of the bridge for the trainloads, as well as for the seismic and wind loads, as specified by current design codes, was performed using a finite element model. Besides, after the owner's recent decision to upgrade the bridge to meet modern standards and new types of trains, the necessary strengthening was proposed, and the new estimation of the remaining fatigue life of the bridge after the suggested strengthening was also provided.     

Twim: A MATLAB toolbox for real-time evaluation and monitoring of traffic loads on railway bridges

This paper describes Twim, a toolbox written in the MATLAB computer language. Twim is designed for monitoring bridge behaviour during train passages as well as for performing Bridge Weigh-In-Motion of railway traffic, both in real-time and offline. The algorithms calculate the static bogie loads and bogie distances, as well as the speed and acceleration of the train. Twim also includes visualization functions, automatic identification of known locomotives and an auto-calibration that uses locomotives with known bogie loads. The algorithms used place specific requirements on both the bridge type and the instrumentation of the bridge. These requirements are explained in the paper. The instrumentation of several bridges is described, and some of the interesting results gained through this instrumentation are presented.     

钢管混凝土系杆拱桥动荷载试验

某主跨52m的钢管混凝土系杆拱桥,建成后因外观质量较差而进行了现场实桥承载能力静荷载试验和动荷载试验,本文简要介绍了该桥的动荷载试验过程,对测试结果进行了整理.     

Static analysis of cable-stayed bridge with CFT arch ribs

A new type of cable supported bridge, cable-stayed CFT arch bridge, was proposed and its static strength was studied in this paper. Arch ribs consist of concrete filled steel tubes (CFT). CFTs have high resistance against bending moments and compressive axial forces and are ideal as arch ribs. A cable-stayed CFT arch bridge with a main-span of 300 m was designed and the safety of its structural members was checked by the limit state design method. Large deformation analysis was used to obtain sectional forces. The CFT arch ribs and the steel box girders and towers of the designed bridge satisfied the required safety criteria for ultimate design loads. The applied loads were further increased until the bridge collapsed when the arch ribs buckled. The amount of steel required for the cable-stayed CFT arch bridge was significantly lower than that for the cable-stayed bridge. It has been found that the proposed cable-stayed CFT arch bridge is feasible and potentially economical.