ETC收费车道通行能力探讨

基于交通流理论,结合ETC车道行进车辆最小安全间距的计算结果,提出由限制车速及车辆最小安全距离求解ETC车道最大通行能力的计算方法.并利用Paramics微观交通仿真软件进行了ETC车道通行能力模拟,通过计算及模拟结果的对比分析,验证了该方法的科学性.     

Research on geological structure inversion method with acoustic computed tomography and borehole data

This article firstly proposes two problems related to geological structure inversion with acoustic computed tomography (CT): ① the results surveyed are different from true stratum layers; ② the existing acoustic CT inversion methods are based on wave’s travel route and velocity analysis, which is short of comprehensive analysis of the revealed geological data. Then, it puts forward the method of applying the borehole data to revise acoustic CT investigation result through controlling the boundary velocity. This method comprehensively uses acoustic data and borehole data to invert the rock masses’ shear wave speed. Comparing to calculating the rock mass’ wave speed with acoustic data alone, it makes full use of the information, and the results obtained are closer to real stratum. Finally, it applies the method to engineering project and the results gotten with the method are more accurate, which shows the reliability and accuracy of the method.     

高墩大跨小半径曲线连续刚构桥施工阶段结构分析

结合工程实例广西崇左至靖西高速公路古龙山大桥,采用空间有限元软件MIDAS/CIVIL,对高墩大跨小半径曲线连续刚构桥结构悬臂施工阶段和成桥阶段箱梁的空间位移与应力进行计算分析,为箱梁悬臂施工时的线形、应力控制提供理论依据。     

汽车纵向通过角理论及其作匿求法浅析

本文对汽车纵向通过角进行了理论探讨,提出了通过角等高线概念,并赋予等高线物理意义,给出了纵向通过角的较为快速和准确的工程作图求解方法,使得汽车设计总布置工作更为便捷。同时也对纵向通过角与纵向通过半径定义进行了简单的比较,指出二者的区别与联系,其结果显示纵向通过半径定义工程应用更为便利,而通过角定义则更有利于不同的车之间进行比较,有利于标准的统一性。     

公路路线设计中应注意的问题

公路路线设计水平对公路的施工质量有重要影响.鉴于此,探讨了路线设计应遵循的原则,并介绍了公路路线设计的质量评价标准,同时,分析了在公路路线设计中需要注意的几个关键问题,以期为公路路线设计提供参考借鉴.     

基于轮轨接触的高速铁路钢轨磨耗量

为预测高速铁路钢轨的磨耗量,建立了轨道结构静力学有限元模型和动力分析模型,基于Archard磨耗理论从曲线半径、行车速度、轮轨横移量3个角度计算分析了钢轨磨耗量,利用垂直磨耗深度0.5mm的磨耗量为界反算出通过总质量.计算结果表明：曲线地段钢轨磨耗较为严重,垂直磨耗深度为0.5mm时,直线上通过的总质量为45.9～60.0 Mt,曲线上通过仅为22.9～29.9Mr;相同曲线半径条件下,单轮作用下的接触斑处钢轨磨耗量随着行车速度提高而增大;相同速度和曲线半径下,钢轨磨耗量随着轮轨横移量增大而增大.     

山区客运专线曲线区段钢轨磨耗量的仿真分析

以山区客运专线钢轨磨耗量以及运营安全性作为研究对象,数值仿真作为手段,仿真计算基于Kalker线性蠕滑理论,借鉴Elkins磨耗指数模型,考虑轨道不平顺,车轮踏面与钢轨型面及弹性地基影响,使用SIMPACK软件建立动车组模型仿真,计算了蠕滑率和蠕滑力的大小,讨论了曲线半径对蠕滑率、钢轨磨耗量、减载率及脱轨系数的影响。比较了不同曲线下,两种踏面的动力学性能。随着圆曲线半径减半,LMa（高速动车组踏面）的左轨磨耗量增大了大约6倍左右。从磨耗量和安全性的角度对山区客运专线设计方法提出建议。     

A study on the degree of barrier coverage in wireless sensor networks

Recently, the barrier coverage was proposed and received much attention in wireless sensor network (WSN), and the degree of the barrier coverage, one of the critical parameters of WSN, must be re-studied due to the difference between the barrier coverage and blanket coverage. In this paper, we propose two algorithms, namely,local tree based no-way and back (LTNWB) algorithm and sensor minimum cut sets (SMCS) algorithm, for the opened and closed belt regions to determine the degree of the barrier coverage of WSN. Our main objective is to minimize the complexity of these algorithms. For the opened belt region, both algorithms work well, and for the closed belt region, they will still come into existence while some restricted conditions are taken into consideration.Finally, the simulation results demonstrate the feasibility of the proposed algorithms.     

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目前,国外一些城市对交通影响评价工作的起评阈值进行了研究,即当建设项目规模或周边交通状况达到一定程度时需要开展交评工作,而国内城市开展交评工作相对较晚,对交评阈值相关研究和规定多停留在经验判断的阶段. 本文在总结国外城市交评起评阈值的基础上,根据北京市几年来交通影响评价工作经验,提出北京交评起评规模以公建类建筑面积2万平方米为基准,居住起评规模为公建2-3倍,远郊区为城八区对应建筑类型起评规模的2倍.     

大跨连续刚构弯桥弯曲效应研究

借助有限元软件,建立某连续刚构弯桥的三维仿真分析模型,通过对不同曲线圆心角引起的结构受力和变形进行比较,归纳出圆心角对于大跨径连续刚构弯桥静力特性的影响,对大跨连续刚构弯桥的设计和计算提出相应的建议。