G305国道田庄台辽河公路大桥设计综述

新建的G305国道田庄台辽河公路大桥主桥采用了六跨悬浇连续箱梁,桥址处水深流急,是我省最复杂的桥梁之一,对大桥的设计情况进行了概要总结。     

CONFORM连续挤压包覆设备

介绍了ＣＯＮＦＯＲＭ连续挤压和包覆的工作原理，重点比较了国际上三种包覆设备的优缺点，阐述了我院研制成功的ＳＬＪＢ３５０连续挤压包覆机各种设备的组成。     

Influence of Track Parameters on Welded Turnout Group

Introduction Welded turnout is a key part for continuouswelded rails (CWRs). Longitudinal force and dis-placement of rails should be considered in the designof welded turnout. When the distance between thewelded turnouts at places like railway stations is…     

预应力现浇混凝土连续箱梁施工

介绍了沈大高速公路改扩建工程后盐立交第一合同段预应力现浇连续箱梁施工工艺,为今后预应力现浇连续箱梁的施工提供了宝贵经验。     

朝阳东大桥主桥桥型构造特点

本文分析了朝阳东大桥主桥自锚式钢管混凝土拱桥桥型构造特点,可供同类型桥梁设计参考。     

悬臂浇注连续箱梁腹板下弯束的设置分析

针对主跨为110m的预应力混凝土连续梁在悬臂浇注阶段出现腹板裂缝的情况,运用有限元软件比较分析了4种不同腹板束的布置方式,并提出了腹板下弯束的设置建议。     

A network optimization-based approach for crowd management in large public gatherings

Effective crowd management during large public gatherings is necessary to enable pedestrians' access to and from the venue and to ensure their safety. This paper proposes a network optimization-based methodology to support such efficient crowd movement during large events. Specifically, a bi-level integer program is presented that, at the upper-level, seeks a reconfiguration of the physical layout that will minimize total travel time incurred by system users (e.g. evacuees) given utility maximizing route decisions that are taken by individuals in response to physical offerings in terms of infrastructure at the lower-level. The lower-level formulation seeks a pure-strategy Nash equilibrium that respects collective behavior in crowds. A Multi-start Tabu Search with Sequential Quadratic Programming procedure is proposed for its solution. Numerical experiments on a hypothetical network were conducted to illustrate the proposed solution methodology and the insights it provides.     

Connecting e-hailing to mass transit platform: Analysis of relative spatial position

This paper analyzes and compares two different relative spatial position (RSP) designs in an integrated e-hailing/fixed-route transit system: a zone-based design that operates e-hailing vehicles within a zone, and a line-based design that operates e-hailing vehicles along a fixed-route transit line and with a stable headway. To conduct a meaningful comparison, the optimal design problems for both systems are formulated using a same analytical framework based on the continuous approximation approach. A comprehensive numerical experiment is performed to compare various cost components corresponding to the optimal designs, and a discrete-event simulation model is developed to validate the analysis. The analytical and simulation results agree with each other well, with a discrepancy in the total system cost less than 5% in most test scenarios. These results also suggest that the line-based system consistently outperforms the zone-based system in terms of both agency and user costs, for all scenarios tested. Compared to the zone-based design, the line-based design features a sparser fixed-route network (resulting in larger stop spacing) but a higher dispatching frequency. It is concluded that the higher efficiency of the line-based design is likely derived from the strategy of operating e-hailing vehicles with a more regular route/headway structure and allowing ride-sharing.     

材料参数对高速铁路连续梁桥地震易损性分析的影响研究

中等跨径的预应力混凝土连续梁广泛应用于高速铁路,以往震害及实验都表明该类桥型在地震下的破坏集中在桥墩和支座位置。为了研究材料参数对高速铁路连续梁桥地震易损性的影响,采用IDA方法,利用有限元软件Open Sees建立地震易损性分析模型。定义4种破坏极限状态,基于对数正太分布假设绘制各个破坏状态对应的易损性曲线。通过更改材料参数得到新的计算模型,并通过对比易损性计算结果来评价材料参数对桥梁抗震性能的影响。结果表明,高速铁路连续梁桥桥墩配箍率较低,提高桥墩混凝土强度等级对桥梁抗震性能改善较大。     

预应力混凝土箱粱桥裂缝成因分析

分析了预应力混凝土梁桥常见裂缝的产生原因,提出了设计中控制裂缝的方法,供工程技术人员参考。