探讨高速公路沉降预测的数学方法

总结以往荷载稳定后的沉降预测方法，并将其划分为半数学方法与纯数学方法，寻找各种预测方法相互之间的联系与差别，提出在研究沉降预测的新方法时应考虑的两个因素。     

土工格室在加固沙漠高速公路路基中的应用

基于土工格室的特殊力学性能，利用其加固沙漠路基。采用Duncan—Chang双曲线模型、Biot固结理论对土工格室加固沙漠路基的机理进行理论研究，并铺筑了野外试验路对理论分析结果验证。结果表明，土工格室对提高沙基承载能力和抗剪能力效果非常明显，能达到减薄路面结构层的目的。     

大气CO2浓度增加对根瘤和菌根活动的影响

大气CO2浓度增加明显促进植物根系与固氮细菌及菌根真菌的共生。CO2浓度增加条件下，根系结瘤量增多，平均瘤重增加，单株固氮活性提高，但固氮比活性的变化在不同物种和不同生长阶段的表现不一致。CO2浓度增加同时还提高菌根在植物根系的侵染率。     

高速公路养护机械的现状与发展趋势

介绍了国内外高速公路养护机械的发展状况，分析了我国公路养护机械存在的问题，从高速公路养护模式改革，建立路面养护管理系统，提高养护机械设备的科技含量和养护机械的选型和配备等方面阐述了我国高速公路养护机械的发展对策。     

高架桥梁地震响应磁流变阻尼器(MR)半主动控制

通过比较被动、主动控制方法的控制效果,研究了磁流变(Magneto-Rheological)阻尼器半主动控制方法在高架桥梁抗震控制中的作用。根据高架桥梁的结构特点,将典型的墩-支座-桥面结构简化为一个两自由度的线性系统,依据3个设计目标:最小化支座响应、最小化桥墩响应及最小化两者响应,分别用高阻尼的橡胶支座进行被动控制、用二次线性调节器(LQR)方法进行主动控制、以MR阻尼器为半主动控制设备,用二次线性调节剪切最优控制器(LQR-Clipped)控制方法进行半主动控制。分别使用上述3种控制方法对同一个系统,在EI-Centro、Gebze、Maxico3种地震激励下进行数值计算。数值结果表明,在最小化支座响应及最小化两者响应控制目标时,MR半主动控制与主动控制具有相同的控制效果,但在最小化支座响应时,桥墩的响应很大;然而,最小化两者响应时,支座及桥墩均有很好的控制效果。     

成南高速公路交通事故的基本特点分析

在本文,作者通过对成都至南充南高速公路(0～75km)自2002年12月通车到2004年11月所发生的交通事故进行了统计,分析了该路段交通事故的特点、成因,在此基础上提出了预防和减少高速公路交通事故的对策。     

Development of the Driving Simulation System MOVIC-T4 and Its Validation Using Field Driving Data

Underground urban expressways are a possibility for solving many existing transportation-related problems, such as traffic congestion in high density areas and the division of neighborhoods due to elevated roadways. However, they may also pose high risks regarding traffic safety. Therefore, it is important for a pre-analysis of traffic safety to be made. This paper describes recent efforts to develop a driving simulation system, MOVIC-T4, for traffic safety analysis of underground urban expressways. In order to develop a small portable simulator, a small-sized motion-base with two-degrees-of-freedom is used to duplicate accel-eration cueing together with a head-mounted-display (HMD) for the visual system. An overview of this sys-tem is given and the reliability of driving data obtained from the experiments using MOVIC-T4 is discussed through a validation study using field driving data. The results of validation indicate that the perceived speed, distance headway, and physiological data in the simulator show the almost same trend as that in the real world, but larger decelerations tend to be produced in the simulator.     

On the Effects of Central Japan Expressway＇s Commuter Toll Discount Policy in Nagoya Area

Road pricing policies have two equally important objectives that have to be considered： the optimal use of the road network and the fiscal sustainability for the management of the network. The aim of this work is to examine the effects on these two objectives of a recent pricing policy implemented in Japan＇s expressway networks. Recently the Nippon （Japan） Expressway Companies （NEXCO, operators of Japan＇s nation wide expressway network） have implemented several toll discount policies for users equipped with electronic toll collectors （ETCs）. One of the policies is the commuter discount policy that discounts 50% for a journey on the NEXCO expressway no longer than 100 km during the commuting peak hours. This paper examines its effect on congestion reduction in the road network of Nagoya area and its influence on the use of expressways operated by another major local public expressway company in Nagoya. The congestion easing effect of this policy is compared with a potential marginal cost pricing scheme. These observations suggest that policy coordination regarding toll levels is needed for expressway corporations and transportation authorities for improving transportation efficiency of utilization of the whole network.     

城市地下快速路入口段火灾烟气蔓延规律

依托上海北横通道泸定路枢纽工程,建立依托工程的全尺寸仿真模型,选取城市地下快速路入口段的主线风速和匝道风速作为变量,研究火灾发生后隧道内人员安全高度处的温度、能见度、CO浓度等变化规律。结果表明,主线风速与匝道风速的提高都会导致温度下降速率减缓,能见度上升,CO浓度降低,但是匝道风速对烟气的影响要弱于主线风速的影响。主线与匝道共同提供排烟风速时,保持临界风速即可有效排烟,主线为1.72 m/s,匝道为1.84 m/s。     

高温下钢筋砼框架力学性能的数值模拟

运用虚功原理,推导建立了高温下钢筋混凝土的梁单元模型,编制了钢筋混凝土结构高温反应的全过程分析程序,考虑了高温下结构的几何非线性效应,程序的有效性得到了其他学者试验结果的验证.利用该程序对某轴力作用下的钢筋混凝土梁进行了高温反应分析,研究结果表明:(1)进行高温下结构反应的全过程分析时,有必要考虑几何非线性的影响;(2)轴力不变时,随着梁所承担的竖向荷载的增加,梁的跨中挠度逐渐增大,同时,随着竖向荷载的增加,几何非线性效应对梁跨中挠度的影响程度差别不明显;(3)竖向荷载不变时,随着梁所承担的轴力的增加,几何非线性效应使梁的跨中挠度逐渐增大;(4)是否考虑几何非线性对梁的耐火极限计算结果影响较大.