整体式衬砌台车在铁路客运专线隧道中的应用

铁路客运专线隧道施工工期紧、质量要求高,如何保质、保量、快速安全地完成施工将直接影响到工程的社会效益和经济效益。以石(家庄)太(原)客运专线太行山隧道9号斜井工区为例,介绍了整体式衬砌台车的结构、就位与调试(钢轨铺设、清理及刷油、快速就位与调试),以及二次衬砌混凝土浇筑中应注意的台车上浮、跑模及混凝土管道堵塞等问题。     

Experimental Research on Atmospheric Electric Field and Extensive Air Shower Particle Increasing During Thunderstorms with ARGO-YBJ

From April lst to August 14th, 2006, thunderstorms had been recorded at Yangbajing Cosmic Ray Observatory by ARGO-YBJ experiment. This paper analyzed the correlation between atmospheric electric field (AEF) and "scaler mode" counting rate during thunderstorm. Counting rates of multiplicities n = 1,2 were found to have a large increase ( from 1.02% to 9.03% ), while there was few or no changes in those of multiplicities n =3 and n≥4 during the thunderstorms. The counts of different multiplicities had different feedbacks on the violent change of AEF, which showed that their energy and most components were distinguishing.     

考虑孔隙水压力作用的二级边坡稳定性上限分析

二级边坡与简单边坡或单级边坡相比,能够在不放缓坡度的情况下提高边坡的稳定性,具有广泛的工程应用价值,在考虑孔隙水压力作用下对二级边坡的稳定性进行了分析,对孔隙水压力的做功功率进行了推导,求出了二级边坡在孔隙水压力作用下的上限解,采用序列二次规划算法对其进行优化计算,并利用工程实例对其解的有效性进行了验证,分析边坡土体物理强度指标在考虑孔隙水压力的作用下对边坡稳定性的影响。     

建构主义理论与情景教学在助产教学中的应用

基于建构主义教育思想的情景教学方法为我们提供了全新的学习理念和教学模式,在构建现代职教体系、推行中高职衔接的现实背景下,为传统教育形式的完善提供了可行性的策略。本文将建构主义和情景教学法应用于高职助产教学中,构建了助产教学中情景教学法的活动框架,分析了情景教学模式在助产教学中的应用意义。     

山区集散二级公路接入口安全处置对策研究

山区集散二级公路交通组成复杂,沿线开口多,路侧行车干扰大,支路口无序接入极易引发交通事故。对接入口交通安全的影响因素进行了深入分析,按照交通特征等将接入口分为3种类型,提出了接入口安全保障对策,并以云南某二级公路为依托工程,对接入口改善措施进行效果评价。采用的接入口安全处置对策,对山区集散二级公路接入口的建设、管养均能适用,对于其他等级公路接入口处置同样具有指导作用。     

CARD/1软件基于改扩建项目的二次开发应用

CARD/1软件系统是专门用来解决工程设计中技术难题的软件,具有更加开放的平台,能很好的进行二次开发,提高设计质量和效率。介绍了该软件基于改扩建项目的二次开发应用。     

基于交通仿真技术的二级公路安全评价方法

二级公路是我国公路系统的重要组成部分。本文根据现场观测结果,以二级公路交通流特性为基础,比较传统安全评价方法,采取基于第85位运行速度差的方法评价二级公路的安全性。考虑二级公路交通组成复杂的特点,运用交通仿真技术建立路网对象,结合现场观测数据完成参数标定,模拟实际交通流运行状况,输出评价指标数据,提出了区别于《公路项目安全性评价指南》所述获取运行速度差的方法。实例研究表明,该方法简单易用、精度较高,且适用范围广。     

Development of a Secondary Crash Identification Algorithm and occurrence pattern determination in large scale multi-facility transportation network

Secondary crash (SC) occurrences are non-recurrent in nature and lead to significant increase in traffic delay and reduced safety. National, state, and local agencies are investing substantial amount of resources to identify and mitigate secondary crashes in order to reduce congestion, related fatalities, injuries, and property damages. Though a relatively small portion of all crashes are secondary, their identification along with the primary contributing factors is imperative. The objective of this study is to develop a procedure to identify SCs using a static and a dynamic approach in a large-scale multimodal transportation networks. The static approach is based on pre-specified spatiotemporal thresholds while the dynamic approach is based on shockwave principles. A Secondary Crash Identification Algorithm (SCIA) was developed to identify SCs on networks. SCIA was applied on freeways using both the static and the dynamic approach while only static approach was used for arterials due to lack of disaggregated traffic flow data and signal-timing information. SCIA was validated by comparison to observed data with acceptable results from the regression analysis. SCIA was applied in the State of Tennessee and results showed that the dynamic approach can identify SCs with better accuracy and consistency. The methodological framework and processes proposed in this paper can be used by agencies for SC identification on networks with minimal data requirements and acceptable computational time.     

广西公路环境问题分析与对策研究

文章对公路建设及营运的环境问题进行分析,提出了提高环境意识与健全制度、强化环境监督管理、制定工程与技术措施等对策建议,为相关部门防治公路环境问题提供参考。     

建构中高职衔接的船体放样课程标准

摘要中高职课程衔接,是中高职教育衔接研究中的一个重要课题。本文分析了建构中高职衔接的船体放样课程标准的思路和方法。并设计出适合统招和单招的中高职学生学习的船体放样课程标准,列出了具体的、有针对性的学习情境。