Durability of Bridge Expansion Joints with Perforated Dowels Under Traffic Impact Loading

In design phases, expansion joints are required to have movement capacity, bearing capacity for static and dynamic loading, watertight, low noise emission and traffic safety. On the basis of the fact that failure due to dynamic loading is the main reason for the observed damages, attention is focused on the bearing capacity for dynamic loading governed by impact, because it differs from the static loading. In this study, from the viewpoint of durability, experimental studies for. dynamic behavior were conducted for aluminium alloy expansion joints with perforated dowels. The validity of the perforated dowels against traffic impact loading was confirmed by both experimental and numerical studies.     

Durability of Bridge Expansion Joints with Perforated Dowels Under Traffic Impact Loading

In design phases, expansion joints are required to have movement capacity, bearing capacity for static and dynamic loading, watertight, low noise emission and traffic safety. On the basis of the fact that failure due to dynamic loading is the main reason for the observed damages, attention is focused on the bearing capacity for dynamic loading governed by impact, because it differs from the static loading. In this study, from the viewpoint of durability, experimental studies for dynamic behavior were conducted for aluminium alloy expansion joints with perforated dowels. The validity of the perforated dowels against traffic impact loading was confirmed by both experimental and numerical studies.     

Dynamic response of RPC-filled steel tubular columns with high load carrying capacity under axial impact loading

Experimental investigation into impact-resistant behavior of reactive powder concrete (RPC)-filled steel tubular columns was conducted,and dynamic response of the columns under axial impact loading was studied by means of numerical simulation method.Increase coefficient of load carrying capacity and ratio of load carrying capacity between steel tube and RPC core of col-umns were obtained.     

固定收费路网条件下交通分配的延迟加载算法

路径收费措施是影响道路网络交通分配的重要因素.受出行时间、道路收费及交通拥堵等多种因素的影响,道路使用者会根据自身习惯、偏好及掌握的信息选择不同的出行路径.综合考虑了路径选择过程中确定性因素和随机性因素对时间感知价值的影响,建立了交通分配的变分不等式模型,设计了求解该模型的延迟加载算法,并叙述了该算法的求解过程.算例结...     

爆炸冲击作用下拱顶式储油罐结构的动力响应(英文)

为研究大型钢制拱顶式储油罐在可燃气体爆炸作用下的破坏和变形特征,对多个储油罐缩比模型进行爆炸实验. 并利用 ANSYS/LS-DYNA 软件,建立了缩比为 1: 25 的 5 000 m3储油罐数值模型,对模型在爆炸冲击作用下的破坏过程进行数值模拟. 实验与数值结果表明: 爆炸冲击波对储油罐缩比模型具有瞬间突跃增压的冲击特性,罐壁迎爆面驻点区域超压峰值最高; 迎爆面中部驻点区首先屈服并带动相邻部分达到屈服状态,同时在变形区周围明显形成不规则的塑性铰环,导致罐壁产生内凹屈曲. 在此过程中,罐内液体既对罐壁产生一定的冲击作用,也能吸收和耗散部分爆炸能量.     

地铁隧道下穿既有高速铁路桥影响分析与施工对策研究

地铁隧道施工引起铁路轨道沉降和变形可能影响正常运营,为控制盾构隧道施工引起的轨道沉降和变形,保护铁路运营安全,对盾构隧道下穿铁路段的区间线位及工程风险进行研究。文章以某市地铁1号线下穿既有高速铁路桥为依托,采用计算软件对隧道下穿既有高速铁路桥进行了数值模拟分析,得到了最大沉降量为11mm,超过了6mm的容许沉降量;通过分析施工过程中沉降情况,提出了施工建议。可为同类工程提供参考。     

Study on one-dimensional consolidation of soil under cyclic loading and with varied compressibility

This paper presents a semi-analytical method to solve one dimensional consolidation problem by taking consideration of varied compressibility of soil under cyclic loading. In the method, soil stratum is divided equally into n layers while load and consolidation time are also divided into small parts and time intervals accordingly. The problem of one-dimensional consolidation of soil stratum under cyclic loading can then be dealt with at each time interval as one-dimensional linear consolidation of multi-layered soils under constant loading. The compression or rebounding of each soil layer can be judged by the effective stress of the layer. When the effective stress is larger than that in the last time interval, the soil layer is compressed, and when it is smaller, the soil layer rebounds. Thus, appropriate compressibility can be chosen and the consolidation of the layered system can be analyzed by the available analytical linear consolidation theory. Based on the semi-analytical method, a computer progra     

Study on one-dimensional consolidation of saturated soil with semi-pirviovs boundaries and under cyclic loading

The variation of effective stress ratio of stratfied soil with semi-pervious boundaries and under cyclic loading was analyzed on the basis of Terzaghi's one-dimensional consolidation assumptions. A solution by Laplace Transform was obtained for the case when the soil was under time-varied loading. With numerical inversion of Laplace Transform, some useful results were obtained for several kinds of commonly encountered loadings. The results can be meaningful in engineering practice.     

Study on one-dimensional consolidation of saturated soil with semi-pervious boundaries and under cyclic loading

The variation of effective stress ratio of stratfied soil with semi-pervious boundaries and under cyclic loading was analyzed on the basis of Terzagh's one-dimensional consolidation assumptions. A solution by Laplace Transform was obtained for the case when the soil was under time-varied loading. With numerical inversion of Laplace Transform, some useful results were obtained for several kinds of commonly encountered loadings. The results can be meaningful in engineering practice. Project supported by the National Natural Science Foundation of China (No. 59908012) and Fok Ying Tung Education Fundation (No. 81067), Education Ministry of China.