泰州长江公路大桥三塔悬索桥的颤振稳定性

为研究三塔悬索桥的动力特性及颤振稳定性,以泰州长江公路大桥主桥为背景,开展数值分析和风洞试验。采用有限元软件ANSYS建立该桥模型,分析中塔对结构振型的影响,分析结果表明:中塔的设置使影响结构颤振稳定性的关键模态的频率降低很多。对节段模型进行颤振稳定性风洞试验,试验结果表明:将检修车轨道移到采用尖角型风嘴的上斜板位置后,模型在+3°风攻角的颤振临界风速达到63.2 m/s。利用三维耦合颤振分析方法对该桥成桥状态+3°风攻角下桥梁结构的颤振稳定性进行分析,分析结果表明:结构颤振时第15阶振型占绝大部分能量,说明颤振主要以扭转形态为主。     

西—攀高速公路米易滑坡稳定性评价及治理措施

在建高速公路以路基和桥梁方式从米易古滑坡中前部通过,文章介绍了滑坡的工程地质环境和特性,通过宏观地质条件和作用因素对其整体稳定性进行了评价,在此基础上通过力学计算法对稳定性较差的前级次生滑坡进行了定量评价,指出滑坡对在建高速公路的影响,并提出了工程治理措施。通过对此滑坡治理的成功经验为西南山区高速公路建设地质灾害防治提供了一条新思路。     

A dynamic modeling approach to investigate impacts to protected and low-income populations in highway planning

Environmental justice (EJ) assessment has traditionally focused on identifying distributive effects to protected populations. Federal and State highway improvement programs have been established to stimulate economic development for these populations. While this issue has long been recognized as part of EJ initiatives, no quantitative comparisons of highway construction impacts on protected populations have been reported in the literature. This paper presents a dynamic modeling approach to investigate impacts to protected and low-Income populations in highway planning using an integrated Geographic Information System (GIS) and Genetic Algorithms (GAs) optimization framework. Using census and county level parcel data, the model integrates various socioeconomic factors into a GIS while generating highway alignments using GAs. Examples using county level census data from North Carolina are demonstrated to test the sensitivity of generated highway alignments with constrained distances from protected populations. The results indicate that it is important to consider local social and economic effects, in addition to regional planning objectives when measuring the effectiveness of feasibility studies associated with highway construction. Within the proposed modeling framework attention is directed on various EJ initiatives, such as environmental health and safety laws in minority and low-income areas. The model would help planners, designers, and policy-makers understand the intricate interrelationships among local communities, while facilitating more scientific and economically equitable planning for highway construction projects.     

Sight distance analysis of highways using GIS tools

Analyzing the distance visible to a driver on the highway is important for traffic safety, especially in maneuvers such as emergency stops, when passing another vehicle or when vehicles cross at intersections. This analysis is necessary not only in the design phase of highways, but also when they are in service. For its use in this last phase, a procedure supported by a Geographic Information System (GIS) has been implemented that determines the highway distances visible to the driver. The use of a GIS allows the sight distance analysis to be integrated with other analyses related to traffic safety, such as crash and design consistency analyses. In this way, more complete analyses could be made and costs shared. Additionally, with the procedure proposed it is possible to use data regarding the trajectory of a vehicle obtained on a highway with a Global Positioning System (GPS) device. This application is very useful when highway design data are not available. The procedure developed and its application in a case study are presented in this article.     

我国现行公路隧道照明规范亟待修正——公路隧道照明节能减排探讨

文章分析了我国现行公路隧道照明设计规范存在的问题,揭示了《JTJ026.1-1999公路隧道通风照明设计规范》亟待修正的原因;通过对国内外LED灯隧道照明的研究应用情况的分析及LED灯与传统的高压钠灯的综合对比,指出了隧道照明节能减排的途径和隧道照明由功能化向智能化、人性化发展的必然趋势.     

公路隧道减震模型试验及数值模拟

文章以嘎隆拉隧道洞口段为原型,拟定了相似关系,选取了围岩和衬砌的相似材料,制作了公路隧道减震试验模型。在试验模型中设置了减震层,选择了振动台模型试验测点的布置位置,制定了加载制度,进行了振动台加载试验;分析了试验结果,并与有限元分析结果进行了对比,定义了减震率;从应力和应变两方面分析了减震层的动力特性及减震效果,得出减震层的设置对隧道减震能起到一定的作用。     

郎川公路SBR改性沥青混凝土施工

由于交通量大、重载车辆多、部分地区气候恶劣,目前我国已通车的高等公路沥青路面出现了较多的早期病害,为了抵抗高温稳定性和低温冰冻的损坏,路面上面层结合料大多采用了高温性能和低温性能均很好的SBR改性沥青。该文主要介绍SBR改性沥青上面层的配合比设计和施工及其存在的技术问题。     

光面爆破技术在毛坝隧道的应用

毛坝隧道采用新奥法施工,在洞身开挖中进行光面爆破,并结合实际情况进行参数调整和效果检验以提高洞身开挖施工质量,有效地控制了超、欠挖,使隧道的光面爆破取得了良好的效果。     

辽宁省公路边沟设计方法初探

对规范确定的边沟设计方法进行探讨,结合各地降雨资料,形成易于掌握的边沟水文、水力计算公式,以方便设计、合理确定边沟尺寸,还可以节省占地及节约工程投资。     

土壤固化剂稳定细粒土基层试验研究

利用室内试验对固化剂稳定土的无侧限抗压强度、回弹模量、冻稳定系数和承载比等物理力学性质进行了研究,并结合试验路段检测结果研究了GSS固化剂加固路基土的施工工艺和技术指标。