浅析车站过渡工程联锁设计

信号过渡工程是相对信号正式工程而言,其设计的优劣会对正式工程有直接影响。信号正式工程先期施工,但由于客观原因不具备开通条件,需要在正式工程基础上进行过渡工程设计,现就过渡工程的信号联锁设计进行简单分析。     

Mapping evacuation risk on transportation networks using a spatial optimization model

The focus of this paper is on the development of a methodology to identify network and demographic characteristics on real transportation networks which may lead to significant problems in evacuation during some extreme event, like a wildfire or hazardous material spill. We present an optimization model, called the critical cluster model, that can be used to identify small areas or neighborhoods which have high ratios of population to exit capacity. Although this model in its simplest form is a nonlinear, constrained optimization problem, a special integer-linear programming equivalent can be formulated. Special contiguity constraints are needed to keep identified clusters spatially connected. We present details on how this model can be solved optimally as well as discuss computational experience for several example transportation networks. We describe how this model can be integrated within a GIS system to produce maps of evacuation risk or vulnerability. This model is now being utilized in several research projects, in Europe and the US.     

复杂环境下地铁暗挖车站双侧壁导坑法支撑体系优化

重庆轨道交通10号线工程渝北广场站为大断面暗挖隧道,车站位于重庆市区繁华地段,为保证车站隧道的安全施工以及邻近既有建筑结构的安全,对暗挖隧道开挖施工方案进行优化设计。采用Midas GTS有限元数值软件,对弧形壁(原双侧壁)和直壁法(双侧壁)开挖方案进行全过程动态模拟,结合监控量测数据,综合对比分析隧道变形和支护结构内力。结果表明,本工程地质条件下,采用直壁法施工方案切实可行,研究成果可为类似地质条件中大断面隧道施工方案的优化设计和最终决策提供参考。     

一种船舶浮态计算新方法

本文介绍了一种基于四面体网格的船舶浮态优化计算方法，并以某梯形船为例进行了浮态计算。     

互联网DNS的运维风险与优化方案分析

互联网业务是未来电信行业的发展方向,互联网域名解析系统（DNS）作为互联网业务的支撑系统,必须与电信运营企业的业务发展需要相适应。简要分析了运营企业当前DNS系统存在的运维风险,并针对系统的问题提出了优化方案建议。     

改善信号供电电源质量的装置

在铁路行车信号设备运行中，安全可靠供电是保证铁路运输的基础。在利用接触网作为信号设备第2路电源时，既有接触网供电装置由于没有对电源的电压波动、干扰谐波进行净化处理，经常出现烧坏设备的情况，急需进行优化改造。采用直流环节实现输入电压和输出电压解耦装置，有效地解决了输入电压品质差的问题。     

佛莞城际铁路长隆站平面优化设计研究

为了在满足长隆地下站运输需求的基础上,尽量缩小车站规模,降低工程投资,从整个珠三角城际网的交路设置、车站折返能力、折返线有效长度等主要技术参数入手,分析长隆站在整条线路及整个城际线网中的功能定位和对整个线网的灵活性、适应性的影响,对长隆站平面布置进行多方案技术经济比选,并通过对折返线有效长进行优化特殊设计,即列控系统采用虚拟一定线路长度数据的方法,推荐的车站布置满足长隆站折返能力的需求,并大大降低车站规模,节省工程投资。     

某车型后减振器上支座失效分析优化

针对某车型整车道路试验过程中出现的后减振器上支座失效问题,通过查看分析故障件的失效状态,结合应用Abaqus软件进行CAE仿真分析,确定了其失效的主要原因是由于在整车运动过程中,上支座衬套的橡胶凸台的应力太大。对此提出了改进的设计方案,通过台架试验和整车道路试验的验证,结果表明,改进后的后减振器上支座解决了耐久失效问题,同时经整车NVH和操稳性能评价后确认改进方案未对整车性能产生不利影响。     

铲土运输机械作业组合系统的优化

在绘制出不同作业距离段铲土运输机械的作业生产率和单位土方施工成本曲线后，把各段曲线拟和成多项式并数字化，再经过生产率和成本方程的规格化处理，建立起评价方程，并利用该方程可对机械组合系统的综合作业指标进行定量分析和作业组合方案实行优化。     

Joint optimization of freight facility location and pavement infrastructure rehabilitation under network traffic equilibrium

Establishment of industry facilities often induces heavy vehicle traffic that exacerbates congestion and pavement deterioration in the neighboring highway network. While planning facility locations and land use developments, it is important to take into account the routing of freight vehicles, the impact on public traffic, as well as the planning of pavement rehabilitation. This paper presents an integrated facility location model that simultaneously considers traffic routing under congestion and pavement rehabilitation under deterioration. The objective is to minimize the total cost due to facility investment, transportation cost including traffic delay, and pavement life-cycle costs. Building upon analytical results on optimal pavement rehabilitation, the problem is formulated into a bi-level mixed-integer non-linear program (MINLP), with facility location, freight shipment routing and pavement rehabilitation decisions in the upper level and traffic equilibrium in the lower level. This problem is then reformulated into an equivalent single-level MINLP based on Karush–Kuhn–Tucker (KKT) conditions and approximation by piece-wise linear functions. Numerical experiments on hypothetical and empirical network examples are conducted to show performance of the proposed algorithm and to draw managerial insights.