如何加大农村公路工程质量监督力度

分析了五年来辽阳市农村公路建设质量的形势;强调质量监督下作在农村公路建设项目管理中的重要性和加强农村公路下程质量监督管理应做好的几方面下作。     

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随着我国公路隧道建设的蓬勃发展,连拱隧道的修建也越来越多。连拱隧道一般应用于中短隧道工程,常常存在浅埋偏压、地质条件较差等问题。河北省张石高速公路岔道2号隧道全长188m,属于双连拱隧道。围岩级别主要由IV、V两级构成,进口段围岩比较破碎,埋深较浅同时具有偏压现象,给施工带来了一定难度。本文采用现场监测与数值模拟两种手段,对隧道浅埋偏压段围岩开挖后的位移变形进行了分析研究。研究结果表明两种分析结果基本吻合,可见采用数值模拟方法在隧道工程分析上是可行的,同时也弥补了单一的现场监测方法存在的预见性较弱的缺陷。     

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设计采购施工（EPC）总承包是项目管理的重要形式。本文主要分析了EPC总承包模式下设备和材料采购分级管理的原则及方法,研究了在项目建设过程中采购方对承包商进行合理监督的质量控制方法。结合作者分管的工作,本文提出了总承包项下设备和材料采购的重要性分级方法,建立了分级采购管理的程序。本文还指出了设备和材料采购分级监督的具体内容以及实施过程中可能出现的问题及协调方法。论文提出的、基于经验的发挥业主和EPC承包商各自的优势、促进他们之间的协作的思路与方法对改进项目管理质量具有现实意义。     

公路工程监理人员执业动态管理探讨

通过资格审查、跟踪管理、年度考评、建立档案这四个阶段的动态管理,可以保证从业监理人员素质,提高监理人员执业水平,进而提高监理工作质量.     

谈勘察设计企业全面预算管理

全面预算管理在国内外企业中已经取得了成功.勘察设计单位改制后也应引入全面预算管理,实现集团化发展的战略目标.对全面预算管理的内涵及在勘察设计单位中的应用过程进行了探讨.     

车辆超载作用对路面的影响分析

利用Matlab软件编制程序,对车辆超载问题进行了仿真,分析了由于路面不平整度引起的车辆动荷载和动荷载系数变化规律,得到车辆超载率与车辆动荷载和动荷载系数之间的关系。为路面设计和车辆与路面之间的相互作用提供了理论基础。     

矿山法海底隧道废水排水系统设计实践

以青岛胶州湾海底隧道工程为依托,对废水系统排水能力的确定、废水提升方案的选择及废水泵房优化设计等方面进行分析,探讨矿山法海底隧道废水排水系统的主要关键技术。主要结论如下： 1）废水排水能力确定的关键在于隧道的结构渗漏水的定量,常规的水下隧道的结构渗漏水量数据不一定适用于海底隧道,必须实际测量后确定; 2）废水提升方案关系到排水的经济性和安全性,核心在于选取安全可靠的水泵类型; 3）废水泵房优化主要从废水池有效容积、结构设计及设备检修等方面进行展开分析; 4）矿山法海底隧道废水排水系统的设计,必须从隧道实际情况出发,综合考虑各类影响因素,以达到安全、经济的设计目标。     

Sliding window method for vehicles moving on a long track

The rail is modelled as a simply supported beam in the vehicle–track coupled dynamics. The beam is formulated by a partial differential equation that is transformed into an ordinary differential equation by the method of mode superposition for numerical calculation. However, the size of the matrix that is formed by the mode-superposition method increases significantly with track length, which limits the calculation efficiency. Some methods have been developed to solve this calculation issue, but they diminish the merits of the vehicle–track coupled dynamics, which would systematically investigate the dynamics of a vehicle and a track from the entire vehicle–track system. A new method is developed to resolve this contradiction. First, a theory based on a sliding window is established to improve the computational stability with respect to the length and the window-movement ratio. Then, two methods, namely finite element method analysis and an analytical solution, are used to verify the accuracy of the new method, which is highly efficient when used in a vertical half-vehicle–track coupled model to calculate the vehicle response when the vehicle moves on a long track. The results of the vehicle response calculated with and without the sliding window show good consistency.     

Field measurements of the evolution of wheel wear and vehicle dynamics for high-speed trains

This investigation demonstrates the wheel wear evolution and related vehicle dynamics of high-speed trains with an operating distance (OD) of around two million kilometres. A long-term experimental test lasting two years was conducted to record the wheel profiles and structural vibrations of various trainsets. The wheel wear, namely the profile shape, worn distribution and wheelset conicity, is investigated for several continuous reprofiling cycles. Typical results are illustrated for the stability analysis, and the ride quality is examined with increasing OD. In addition, the vibration transition characteristics between suspensions are investigated in both the time and frequency domains. The experiments show that the dominant wear concentrates on the nominal rolling radius, and the wear rate increases with OD because of the surface softening resulting from the loss of wheel material. The vibration of structural components is aggravated by the increase of the equivalent conicity of the wheelset, which rises approximately linearly with the wheel wear and OD. High-frequency vibrations arise in the bogie and car body related to the track arrangement and wheel out-of-roundness, causing the ride comfort to worsen significantly. Additionally, the system vibration characteristics are strongly dependent on the atmospheric temperature. Summaries and conclusions are obtained regarding the wheel wear and related vehicle dynamics of high-speed trains over long operating times and distances.     

A framework for travel time variability analysis using urban traffic incident data

This study aims to develop a framework to estimate travel time variability caused by traffic incidents using integrated traffic, road geometry, incident, and weather data. We develop a series of robust regression models based on the data from a stretch in California's highway system during a two-year period. The models estimate highway clearance time and percent changes in speed for both downstream and upstream sections of the incident bottleneck. The results indicate that highway shoulder and lane width factor adversely impact downstream highway clearance time. Next, travel time variability is estimated based on the proposed speed change models. The results of the split-sample validation show the effectiveness of the proposed models in estimating the travel time variability. Application of the model is examined using a micro-simulation, which demonstrates that equipping travelers with the estimated travel time variability in case of an incident can improve the total travel time by almost 60%. The contribution of this research is to bring several datasets together, which can be advantageous to Traffic Incident Management.