Factors affecting the environmental impact of pavement wear

Wear at the interface between flexible pavements and tires influences pavement life, pavement cycle costs, and tire consumption, and is a source of environmental harm. Wear-related processes evolve over time and are affected by a number of boundary conditions, such as interface fluids, water and fuels. We develop a model explaining and predicting mass losses in flexible pavements under carefully controlled conditions, and with estimation of the related environmental costs. We also employed an accelerated loading test. Under normal conditions, the environmental impact of pavement wear is not greatly influenced by mix type or volumetrics. Indeed, the presence of hazmat materials, traditional, dense mixes have an environmental impact that is appreciably lower than that of porous European mixes.     

TBM及其在中国的应用(1)

1前言 这篇报告援引了许多与中国未来工程有关的大型地下工程和特长深埋隧道工程实例.这些工程只有通过运用精湛的隧道施工技术(尤其是高度机械化的TBM)、特别的管理以及认识到采用这些方法所产生的能力的提高和费效比的增加才可能达到成功.这并不意味着毫无问题,而是因为在运用这些创新技术中所遇到的困难被相关部门顽强地克服了.     

A multi-agent architecture for cooperative inter-jurisdictional traffic congestion management

This paper describes , an innovative multi-agent architecture for the provision of real-time decision support to Traffic Operations Center personnel for coordinated, inter-jurisdictional traffic congestion management on freeway and surface street (arterial) networks. is composed of two interacting knowledge-based systems that perform cooperative reasoning and resolve conflicts, for the analysis of non-recurring congestion and the on-line formulation of integrated control plans. The two agents support incident management operations for a freeway and an adjacent arterial subnetwork and interact with human operators, determining control recommendations in response to the occurrence of incidents. The multi-decision maker approach adopted by reflects the spatial and administrative organization of traffic management agencies in US cities, providing a cooperative solution that exploits the agencies’ willingness to cooperate and unify their problem-solving capabilities, yet preserves the different levels of authority and the inherent distribution of data and expertise. The interaction between the agents is based on the functionally accurate, cooperative paradigm, a distributed problem solving approach aimed at producing consistent solutions without requiring the agents to have shared access to all globally available information. The cornerstone of this approach is the assumption that effective solutions can be efficiently obtained even when complete and up-to-date information is not directly available to the agents, thus reducing the need for complex data communication networks and synchronization time delays. The simulation-based evaluation of the system performance validates this assumption. The paper focuses on the distributed architecture of the agents and on their communication and decision making characteristics.     

TBM及其在中国的应用(4)

3.12中国利用西方国家的TBM经验加速发展本国TBM技术的理由 3.12.1技术开发和革新是需要时间的     

如何分析一场比赛

停维修站时间的选择有什么重要性？一个“燃油校正”的单圈是什么？在下文中，您将了解如何从F1比赛画面里获得更多信息     

Development and evaluation of a knowledge-based system for traffic congestion management and control

This paper describes a real-time knowledge-based system (KBS) for decision support to Traffic Operation Center personnel in the selection of integrated traffic control plans after the occurrence of non-recurring congestion, on freeway and arterial networks. The uniqueness of the system, called TCM, lies in its ability to cooperate with the operator, by handling different sources of input data and inferred knowledge, and providing an explanation of its reasoning process. A data fusion algorithm for the analysis of congestion allows to represent and interpret different types of data, with various levels of reliability and uncertainty, to provide a clear assessment of traffic conditions. An efficient algorithm for the selection of control plans determines alternative traffic control responses. These are proposed to an operator, along with an explanation of the reasoning process that led to their development and an estimation of their expected effect on traffic. The validation of the system, which is one of only few examples of validation of a KBS in transportation, demonstrates the validity of the approach. The evaluation results, in a simulated environment demonstrate the ability of TCM to reduce congestion, through the formulation of traffic diversion and control schemes.     

城市地区机械化隧道工程的风险管理

由于相关国际组织长期不懈的努力,隧道工程,特别是城市地区隧道工程的风险管理正成为一种惯例.对于机械化隧道工程情况也是如此,即使常常被认为是一种安全、快速的隧道施工方法,但仍然有许多其它因素决定着这种先进的施工技术的成败.为有助于控制所有重要因素,就需要制定和实施风险管理计划(RMP).文章介绍了风险管理计划的必要元素,并阐述了隧道掘进计划(PAT)方法,以确保城市地区机械化隧道工程获得成功.     

隧道纵向消防通风的对数理论

文章介绍了一种新的隧道防火通风理论.与目前通用理论不同的是,该模型没有从Froude相似准则出发,而是通过对基本热流体动力学方程组的简化、分析,揭示了火源放热率与隧道通风速度和隧道高度之间的逻辑关系,提出了以火势为特征的隧道火灾通风理论;依据这一理论,隧道通风临界速度为火势的对数函数,进而解释了大型隧道火灾中临界速度与火源放热率无关这一重要实验现象;利用新的火势概念,该理论给出了定量的火灾分类准则,并从数学上描述了各类火灾的物理特征;与现有实验数据比较,新理论无需任何实验修正,在所有火源放热率范围内成功地预测了隧道通风临界速度,从理论上克服了现有模型中临界速度随放热率无限增大的问题.由于新理论的二维性质,隧道侧壁面对防火通风的影响仍需进一步研究.     

TBM及其在中国的应用(2)

3工程和技术实例 3.1在长大和深埋隧道工程方面其它国家的经验 3.1.1工程实例 在国际上,许多地铁、公路和水利方面的隧道正投入使用或正在建设之中,还有的才处于计划阶段.     

TBM及其在中国的应用(3)

3.6先进的掘进及支护系统 3.6.1其他先进的掘进技术 除了上述的各种主要的先进TBM技术外,还有下列几种先进的地下掘进技术: