CFRP confinement of bridge columns damaged by premature concrete deterioration: a case study in Texas

In 1998, the Texas Department of Transportation (TxDOT) identified two concrete distress mechanisms occurring on its bridge over Lake Ivie in the west central part of the state: alkali – silica reaction (ASR) and delayed ettringite formation (DEF), collectively referred to by TxDOT as premature concrete deterioration (PCD). The agency sponsored two research projects to investigate the problem. One focused on determining the remaining capacity of PCD-damaged concrete members with a case study of the Lake Ivie bridge and the other assessed treatments that could be applied to members with PCD damage. Based on findings of the study, TxDOT applied a system that waterproofed the damaged columns and then confined them using resin-bonded carbon fibre reinforced polymer (CFRP) fabric strips. This paper describes the efforts of TxDOT to mitigate PCD damage for its Lake Ivie bridge.     

黄土充填开采从地表至井下运输系统的设计

为了提高煤炭资源的采出率、减少资源浪费、改善矿区地表周边环境质量，霍州煤电集团率先提出建筑物下长壁综合机械化采煤黄土充填技术。本文根据黄土充填开采运输系统在建筑物下长壁综合机械化采煤黄土充填技术中的重要性，分析了黄土运输的自然特性，并对黄土充填开采地表至井下重要运输环节一投料井进行了设计及研究。结果表明，黄土充填开采地表至井下运输系统可满足工作面充填开采的需要。     

综采工作面轨道顺槽运输系统的选定

通过实例，介绍了综采工作面准备期间轨道顺槽运输系统的选定方法，包括：绞车位置、型号及钢丝绳的选型计算和运输的注意事项。     

Expression of the transportation of corrosive media into epoxy coating using nano-indentation

Nano-hardness (H_nano) and nano-elastic modulus (E_nano) of corroded coating surface layer were investigated using nano-indentation after epoxy coated specimens were immersed in 5% NaCl solution. The penetration depths (d) of corrosive media into epoxy coating were calculated fitting the curves of (H/E)_nano vs. indentation depth (h). EIS spectra of epoxy coated specimens immersed in 5% NaCl solution for different time were measured. Finally the relationship of capacitance (C_f,T) of corroded epoxy coating with the penetration depth of corrosive media was studied. The experimental results showed that the transportation process of corrosive media into epoxy coating was studied through the profiles of (H/E)_nano with indentation depth. The penetration depth of corrosive media into the epoxy coating increases rapidly with immersed time firstly, and then increases slowly. The capacitance of corroded epoxy coating has a linear function relationship with the penetration depth of corrosive media into epoxy coating. Nano-indentation can be used to study the transportation process of corrosive media into organic coating.     

全断面掘进机(TBM)刀盘总推进力的分析计算

探讨了在不同的地质条件下TBM刀盘总推进力的设计计算方法,有利于优化TBM的结构参数和总装机功率,提高TBM适应不同地质条件的能力,并以ROBBINS(美)公司MB264-311型TBM为例进行了模拟计算,证明该计算方法正确有效。     

GPRS技术在油田监测系统中的应用研究

介绍了在VisualBasic6.0环境下,利用Winsock控件,通过GPRS网络实现上位机和终端之间通信,从而实现远程油田实时监测的系统.方案通过GPRS网络实现油井测点数据的传输,提高了运行的可靠性并降低了系统成本,解决了动态IP访问、与本地监控的协调、GPRS信道流量优化等问题.着重对系统的实时性和可靠性设计进行了分析和论述.具体说明了系统实现中的难点和关键技术,分析了系统的性能,同时展望了该技术广泛的应用前景.     

时间约束下的运输网络最短路径研究

研究了电子商务下在线零售企业在物流配送时运输网络设计的问题。针对大多数企业的实际情况,提出了在送货时间约束的条件下,如何优化运输网络,以达到在降低运输成本的同时提高顾客响应能力。     

基于注意力机制和分时图卷积的公交客流预测

实际公交路网通常为复杂的非线性时变系统,难以有效构建线路间的时空间依赖关系.因此,文中提出基于注意力机制和分时图卷积的公交客流预测模型,提升公交客流量预测的准确性.首先通过长短期记忆网络提取历史数据中的时间特征,并利用通道注意力模块加权特征.再使用分时图卷积方法分析不同时段下公交线路间的空间依赖性,根据预测时段选择不同...     

步行校园的建构

通过比较国内外大学校园步行环境的规划发展状况,分析我国校园步行系统规划中存在的问题,指出我国大学校园应建立以人为导向的校园交通系统,提出步行校园的建构导则。     

大城市交通与建成环境综合规划的范式扩展与深化 — —中美案例的比较与启示

城市交通与建成环境规划是城市 综合规划的核心内容,在城市的不同发展阶 段,其社会经济条件与主要规划理念、政策 保障之间的匹配度对城市发展产生了持续影 响。在中国城市面临空间增长型向内涵提升 型转变发展的重要时期,进一步审视发达 国家大城市交通与建成环境综合规划在不 同阶段的范式变化（包括主要背景、发展理 念、规划要点、实施效果等）,对比中国大城 市发展的阶段性特征,将为中国大城市交通 与建成环境的提质发展提供有益参考。本文 通过梳理中美两国部分大城市交通与建成 环境规划的发展脉络,总结不同阶段的范式 发展特征,结合当前中国大城市空间发展趋 向,为中国大城市交通与建成环境的综合发 展提供借鉴和指导。