地震作用下双薄壁高墩刚构桥桥台处的碰撞效应及减碰措施          下载免费PDF全文

徐略勤  魏晓龙 《地震工程学报》2017,39(3):425-433

针对双薄臂高墩连续刚构桥两侧桥台处主梁与背墙的碰撞现象,基于桥台-背土作用简化模型和Kelvin碰撞模型,采用非线性时程法研究碰撞对双薄臂墩地震剪力、弯矩、曲率和位移,以及支座纵向变形的影响。提出可牺牲背墙、阻尼器、加强型横系梁等三种减碰措施,并对比分析其减碰效果。研究表明:碰撞会显著增大高墩的地震内力和曲率响应,降低墩顶位移和支座的纵向变形;碰撞刚度的变化对碰撞效应的影响在20%以内;可牺牲背墙和阻尼器两种减碰措施均可大幅降低桥墩的地震内力和曲率,使其接近不考虑碰撞时的状态,阻尼器同时还可以保护支座不超过容许变形,而可牺牲背墙则会导致支座的地震破坏;加强型横系梁不能发挥减碰作用,反而会增大桥墩的地震响应。  相似文献   

大跨铁路钢桁连续梁桥减隔震方案比较研究   总被引：5，自引：2，他引：3       下载免费PDF全文

杨华平  钱永久  樊启武  黎璟  邵长江 《地震工程学报》2017,39(6):1097-1104

为研究适用于大跨铁路钢桁连续梁桥的减隔震方案及合理优化参数,以一座全长504 m的三跨铁路钢桁连续梁特大桥为工程背景,使用非线性结构分析软件SAP2000建立有限元模型,采用快速非线性分析方法分析对比摩擦摆、阻尼器、速度锁定器等减隔震方案在各种装置参数下的减震效率。研究表明:由于大跨铁路钢桁连续梁桥墩身自振导致的地震力较大,摩擦摆方案内力减震效率一般,同时墩底内力对滑动面半径变化并不敏感,在选取滑动半径时应更多地考虑行车平顺性和梁端位移值的限制。速度锁定器会极大地增加此类桥梁地震输入能量,不适用于此类桥型。阻尼器方案对活动墩内力减震效果明显,但不能有效降低固定墩内力。摩擦摆支座附加阻尼器组合减震方案能有效控制此类桥梁的内力和位移响应。研究结论可为大跨度钢桁连续梁桥减隔震设计提供参考。  相似文献   

圆柱形支撑大跨度建筑结构强震冲击分析模型仿真   总被引：3，自引：2，他引：1       下载免费PDF全文

吴海波  王新妮 《地震工程学报》2018,40(1):48-53

圆柱形支撑大跨度建筑稳定性较差,不能在强震冲击下保持稳定的结构状态。为解决此问题,设计圆柱形支撑大跨度建筑结构强震下冲击分析仿真模型,通过圆柱分析法则的确定、有限元支撑模拟分析与监测、圆柱形支撑体系承载能力分析以完成模型的仿真分析与监测。基于此对大跨度建筑结构强震冲击进行静力分析,调整强震冲击下模型的结构,完成模型的搭建。模拟强震冲击环境,设计对比实验结果表明,应用圆柱形支撑大跨度建筑结构强震下冲击分析仿真模型,可明确圆柱形支撑大跨度建筑薄弱点,发现稳定性较差建筑结构单元,达到提升圆柱形支撑大跨度建筑在强震冲击下稳定性的目的。  相似文献   

考虑支座摩擦滑移及结构碰撞的非规则人字形桥梁地震响应分析          下载免费PDF全文

闫磊  李青宁  刘芳平  申纪伟  程龙飞  杨茂 《世界地震工程》2018,34(2):044-54

针对非规则人字形桥梁在地震作用下灾变严重的问题,以一座非规则人字形桥梁为研究对象,建立其空间分析模型,研究综合考虑支座摩擦滑移、结构碰撞对非规则人字形桥梁地震响应的影响。结果表明:邻梁间的碰撞作用可使得桥梁墩顶位移及内力相比不考虑时有所减小,但同时也使梁体产生了较大的加速度脉冲效应;当考虑支座摩擦滑移和结构碰撞时,固定墩墩顶位移和邻梁相对位移峰值有一定程度增大,然而对梁体加速度脉冲效应结果影响并无统一规律;纵向地震波作用下,非规则人字形桥梁不仅存在顺桥向的碰撞,横桥向的碰撞响应也不容忽视。非规则人字形桥梁进行抗震设计计算时应选取符合实际情况的计算模型,考虑支座摩擦滑移及结构间的碰撞。  相似文献   

不同水动力扰动下太湖沉积物的悬浮特征   总被引：10，自引：2，他引：8  

罗潋葱  秦伯强  胡维平  张发兵 《湖泊科学》2004,16(3):273-276

利用2002年7月及2003年4月分别在太湖乌龟山和梅梁湾的水动力观测资料,计算了波浪和湖流产生的湖底切应力,分析了二者对太湖沉积物悬浮的不同贡献.结果发现,在小扰动情况下,流切应力大于波切应力,但不能引起沉积物的悬浮;在强扰动情况下,底流对沉积物悬浮的影响可以忽略,且扰动越强,其作用越小,而波浪的影响却愈加突出;在中等扰动下,二者的相互作用产生沉积物的悬浮,但波浪的作用较为显著.该结论能为计算太湖水体悬浮物浓度和动态内源释放提供重要的参考依据.  相似文献   

Pseudo‐dynamic testing with substructuring at the ELSA Laboratory     

P. Pegon  A. V. Pinto 《地震工程与结构动力学》2000,29(7):905-925

The paper describes the distinctive features of the pseudo‐dynamic test method as implemented at the ELSA reaction‐wall facility. Both hardware and software aspects are considered. Particular attention is devoted to the digital control system and to a coupled numerical–experimental substructuring technique allowing realistic earthquake testing of very large structures. Mathematical and implementation details corresponding to this testing technique are given for both synchronous and asynchronous input motion. Selected test results illustrate the advantages of the presented features. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

Bayesian probabilistic damage detection of a reinforced‐concrete bridge column     

Hoon Sohn  Kincho H. Law 《地震工程与结构动力学》2000,29(8):1131-1152

A Bayesian probabilistic approach for damage detection has been proposed for the continuous monitoring of civil structures (Sohn H, Law KH. Bayesian probabilistic approach for structure damage detection. Earthquake Engineering and Structural Dynamics 1997; 26 :1259–1281). This paper describes the application of the Bayesian approach to predict the location of plastic hinge deformation using the experimental data obtained from the vibration tests of a reinforced‐concrete bridge column. The column was statically pushed incrementally with lateral displacements until a plastic hinge is fully formed at the bottom portion of the column. Vibration tests were performed at different damage stages. The proposed damage detection method was able to locate the damaged region using a simplified analytical model and the modal parameters estimated from the vibration tests, although (1) only the first bending and first torsional modes were estimated from the experimental test data, (2) the locations where the accelerations were measured did not coincide with the degrees of freedom of the analytical model, and (3) there existed discrepancies between the undamaged test structure and the analytical model. The Bayesian framework was able to systematically update the damage probabilities when new test data became available. Better diagnosis was obtained by employing multiple data sets than just by using each test data set separately. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

测距三角高程跨河水准测量的应用     

李世良 《地理空间信息》2010,8(2):146-147,153

结合大桥工程中跨河水准测量,分别运用常规的测距三角高程法和改进的测距三角高程法进行跨河水准测量,对结果进行比较和研究。  相似文献   

全站仪三维坐标法在桥梁施工测量中的应用   总被引：1，自引：0，他引：1  

田林亚  王进锋  武东辉 《测绘科学》2010,35(3):198-199,202

尽管全站仪三维坐标法已在工程测量领域得到广泛采用,但其测量精度及其影响因素还需要深入分析,使之能合理地应用于具体工程。推导了三维坐标的精度计算公式,分析了测量精度的影响因素,针对特定的测量仪器、测量条件和大气折光误差,计算和分析了测点所能达到的精度,阐明了控制和提高测量精度的措施。将该方法应用于苏通大桥墩塔基础施工测量,根据具体的测量仪器和环境条件等,计算测点的点位中误差和高程中误差分别为±5.9mm和±6.9mm,其精度完全满足施工测量的限差要求,表明测量结果具有较高的精度和可信度。  相似文献   

Response analysis of the Higashi–Kobe Bridge and surrounding soil in the 1995 Hyogoken–Nanbu Earthquake     

Todor Ganev  Fumio Yamazaki  Hiroshi Ishizaki  Masahiko Kitazawa 《地震工程与结构动力学》1998,27(6):557-576

This paper presents results of observation and analysis of the response of one of the longest cable-stayed bridges in the world to the Hyogoken–Nanbu (Kobe) Earthquake of 17 January 1995. It is determined that interaction of the foundations of the bridge towers with the supporting soil plays a decisive role in the overall structural behaviour. The key factor governing the changes of the soil properties at this site is pore-water pressure buildup, which results in liquefaction of the saturated surface soil layers under large dynamic loads. Models of the soil and structure are created and initially validated by accurately simulating the system response to a small earthquake. Soil parameters reflecting the pore-water pressure buildup in the strong earthquake are determined by an advanced non-linear effective stress analysis, combining the Ramberg–Osgood model of stress–strain dependence with a pore pressure model based on shear work concept. They are utilized to investigate and simulate the interaction of the foundation and the supporting soil using the program SASSI with the flexible volume substructuring approach. The results show a good agreement with the observations and have useful implications to the scientific and engineering practice. © 1998 John Wiley & Sons, Ltd.  相似文献