Applicability of highway alignment optimization models

This paper presents an intelligent optimization tool that assists planners and designers in finding preferable highway alignments, connecting specified endpoints or zones. It integrates genetic algorithms with a geographic information system (GIS) for optimizing highway alignments and processes massive amounts of relevant data associated with highway design and alternative evaluation. To show the applicability of the proposed model to a real-world problem, two actual highway projects in the state of Maryland have been analyzed using the model. An extensive analysis of sensitivity to key model parameters is also conducted to describe the model capabilities. The analysis results show that the model can effectively optimize highway alignments in an area combining complex terrain and various types of natural and cultural land-use patterns, and provide detailed information of optimized alignments as a model output. It is also found that the alignments optimized by the model are quite similar to those obtained through conventional manual methods by a state agency, but the model can greatly reduce the time required for highway planning and design as well as produce lower cost solutions. Finally, the results confirm that all dominating and alignment-sensitive costs should be simultaneously evaluated in the alignment optimization process because many trade-off opportunities exist among those costs. The proposed model can greatly contribute to the productivity of highway planners as well as to the quality of the resulting infrastructure.     

Runoff and soil erosion from highway construction spoil deposits: A rainfall simulation study

To measure soil loss from these road construction spoils, 30 rainfall simulations involving five rainfall intensities were conducted to study runoff and soil erosion processes on a road in China. Twenty-five of the rainfall simulations were carried out on loose materials five different slopes. Another five rainfall simulations were conducted on compacted road materials with a slope of 30.6%. The results show that soil bulk density has a positive effect on runoff rate, and the effect of slope on runoff rate changes with rainfall intensity. Higher soil bulk density increases soil loss under low rainfall intensity, but decreases soil loss when rainfall intensity is high. Soil loss is positively related to slope, but the relationship differs from that in prior studied of croplands and disturbed lands. Equations for predicting soil erosion from loose materials and compacted road are developed.     

中日公路隧道建设标准的差异分析

文章通过对中日公路隧道建设标准的比较,分析了中日公路隧道建设标准的差异与原因,有助于隧道设计施工从业者准确把握现有公路隧道规范制定的意图,提高规范的执行和运用能力。     

公路造价管理中存在的问题及对策

文章针对我国公路造价管理中存在的管理人员思想意识不强、素质不高、造价审计职能弱化、变更管理不到位、缺乏完善的定额管理体系、信息化水平低下等问题,提出了相应的解决对策,为建设单位加强公路造价管理工作提供参考。     

杂散电流排流设施有效性评价研究

随着交直流电气化铁路、高压输电线路的大量兴建,管道不可避免受到临近电气化设施的干扰。排除或者减缓杂散电流的主要途径是选择合适的杂散电流排流设施。国内目前应用的排流设施主要有极性排流器、钳位式排流器以及固态去耦合器。通过对这几种排流设施进行的现场测试与评价,总结出了每种排流方式的优点与局限性,可为今后不同干扰情况下选择合理的排流减缓方式提供依据。同时,结合现场实践,提出了杂散电流减缓的研究方向。     

延长气田集输干线管道水害及治理方法

延长气田集输干线输气管道主要敷设于黄土高原地区,地形起伏较大,延河及支流、支沟纵横交错。管道在该类地区易遭受沟头前进、崩塌、岸坡冲毁等灾害的威胁,严重影响管道安全运行。文中在分析该类地区常见水害的基础上,结合近年来水害治理的经验,提出了针对黄土冲沟、黄土崾岘、高陡坎、河流侵蚀等特殊地段的水害治理方法,供其他黄土地区管道的设计、建设借鉴和参考。     

改扩建高速公路基本路段通行能力研究

文章以沪宁高速公路江苏段桩号为K104＋925两侧加宽（两侧拼接）的扩建基本路段为研究对象,利用VISSIM仿真软件,建立高速公路基本路段仿真模型,模拟车流的运行状态及其随时空变化的过程。通过对仿真运行过程的观察及实测数据的分析,对比研究了扩建前后高速公路基本路段的实际通行能力和服务水平。     

储值卡收费系统在广西高速公路中的应用

文章结合目前广西高速公路储值卡收费系统具体情况,对利用储值卡进行高速公路收费工作的业务流程进行了研究,同时介绍了储值卡收费系统整体架构以及数据传输等业务涉及到的关键技术。     

广西山区高速公路分离式路基设计实践

分离式路基在山区高速公路设计中具有很好的灵活性和适应性。文章结合广西山区高速公路分离式路基设计实际情况,从平面、纵断面、横断面设计等方面对山区高速公路分离式路基设计的要点进行了介绍,对设计中需注意的问题进行了探讨。     

关于提高广西高速公路行业公共服务水平的思考

高速公路公共服务水平是高速公路行业发展水平的最终体现。文章基于对广西高速公路行业服务水平的构成要素和现状的分析,探索提高广西高速公路行业服务水平的思路及措施。