拉索是索承重大跨桥梁的重要承力部件；由于拉索质量轻，柔度大，阻尼小，在风的激励下，会发生强烈的振动，其中最为剧烈的是拉索的风雨激振。对此，结构工程师采取了各种措施来控制拉索的风致振动。迄今为止，在拉索上附加耗能减振装置仍然是索承重大跨桥梁拉索振动控制的主要手段。就目前国内外索承重大跨桥梁拉索的振动控制装置种类与性能进行比较和分析，指出它们的优缺点；并展望未来拉索振动的半主动控制和主动控制装置。

通过对原有钢筋混凝土结构扩展散体单元模型予以改进，提出了质点一桁架模型。将钢筋混凝土离散成单个质点，质点之间用桁架杆（非线性弹簧）联结，局部的破坏通过弹簧联结的断裂进行模拟，由此可计算结构从局部破坏到整体倒塌的全过程。借助面向对象的程序（00P）语言visual C+编制了分析软件，并计算了一个地震作用下独柱式桥墩倒塌的实例。计算结果表明，运用散体单元法分析桥梁倒塌，可直观地定性把握结构损伤发展直至倒塌破坏的全过程，对于结构倒塌破坏的机理研究具有重要意义。

In this paper, a method based on the artificial neural network technology, which is used to iden-tify two moving vehicles load on a simply supported bridge, is discussed. A multi-step identification procedure, which can be used effectively to identify multiple vehicle parameters such as loadlocation, load magnitude, andmoving speed, is proposed. The sensitivity of various input variables to the output and the effect of variation ofsample number to the identification result are investigated. The example data for training and verification aregenerated by theoretical simulation. The identification simulation shows that the proposed ANN method andprocedure can identify the moving vehicle load problem with acceptable accuracies. The ANN can also identifythe vehicle loads withclosed spacing and high moving speed, for which a conventional TDM or FTDM does notgive good identification results.

The pushover analysis is becoming popular as a simple method for seismic performance evaluation ofstructures. This paper presented a pushover analysis model, which can take account of soil-pile-structureinteraction. As load pattern for pushover analysis, monotonic increasing inertial forces was applied to asuperstructure and shear deformation was applied to soil respectively. A bridge pier-pile-soil system wasanalyzed by using the presented model, and the results were compared with those of nonlinear dynamictime history analysis, it was showed that the improved pushover method and its parameters determinationwere proper for providing a reasonable estimate of the structural maximum response. In order to embodythe nonlinearity of soil, nonlinear soil springs contacting piles and soil should be adopted in the modelinstead of equivalent linear ones. A static experiment of multi-pile foundation in a shear deformation soilbox was carried out to study the effect of soil movement on a multi-pile foundation, the relationship ofsoil-pile interaction force and relative deformation, and the determination method of the nonlinearinteraction spring.

对人行桥人行激励竖向振动的国内外现有规范和标准进行了比较研究，并探讨了针对侧向人行激振的振动使用性设计方法。建议人行桥梁设计时应首先采用频率调整法，使结构自振频率尽量不落在敏感频率范围内，不能达副频率要求时，再进一步采用动力响应法分析。在参考国外规范的基础上，建议确定竖向和侧向人行激振荷载的计算公式，该公式考虑了高阶分量的影响，还对人行桥振动舒适度标准进行了比较，认为参用英国规范的标准较为合理。