T梁桥绳锯切割拆除方案优化研究与数值模拟分析

为了研究先简支后连续的T梁桥的整体切割拆除关键技术,以三洲沧江拆除工程为研究背景,结合大桥实际情况制订了针对性的大桥上、下部结构整体拆除施工方案。验证了采用2台80t汽车吊分别站位于旧桥左右幅,将左幅旧桥各跨8片独立的T梁分别进行吊运的绳锯切割拆除方法为最优方案。以典型的简支T梁桥结构为例,采用有限元模型分析了拆除工程中T梁桥的力学性能变化。针对三洲沧江大桥的下部结构特点,特别对水上桥墩的拆除方案进行了数值分析,并对钢抱箍平台上拆除盖梁的方案进行了仿真模拟,验证了下部结构拆除方案的可操作性。本桥梁绳锯切割拆除工程的优化方案及关键技术的应用为相似桥梁切割拆除工程提供一定的参考。     

银西铁路引入银川地区方案研究

银川市辖区总人口增长速度明显低于城市建设用地增长速度,反映出城市对人口聚集力不足,城市对外交通是影响城市发展的主要因素。分析银川地区铁路规划存在的主要问题,抓住银西线引入银川地区为城市发展带来的机遇,在解决铁路自身存在问题的同时,选择对城市发展有利的铁路地区规划方案,使铁路规划与城市发展规划有机结合并协调发展。     

大跨度钢箱叠拱桥在高速铁路中的应用研究

新建哈尔滨-大连高速铁路跨越长春市富民大街设计采用138m钢箱叠拱,为国内首次采用的新型拱桥结构,是目前国际上同类桥梁中的跨度最大、位于严寒地区的桥梁,也是国内第一座应用实体圆钢吊杆铁路桥梁,对该桥应用中的关键技术实体圆钢吊杆的连接及低温疲劳特性、拱脚的合理构造及局部应力、对无砟轨道适应性、车桥耦合动力效应等进行了系统计算分析和试验研究,其研究成果已应用于新开河特大桥中,详细介绍桥式方案及在高速铁路应用中的关键技术研究成果。     

铁路桥梁梁端伸缩装置的结构特点探讨

铁路桥梁梁端伸缩装置是大跨度桥梁的重要部件,为实现轨道的连续性和平顺性,需要具备滑动和支撑功能。对国内各种铁路桥梁梁端伸缩装置的结构特点、工作原理以及各自优缺点进行分析对比,目的在于分析出国内自主研发的梁端伸缩装置需要改进的思路和方向。我国要实现铁路桥梁梁端伸缩装置完全自主化,需要吸收国外先进的技术和经验,同时提升自身的制造精度和水平。     

高温隧道施工技术及投资构成分析

在山区铁路隧道工程建设中，因地质条件会遇到具有地热的高温隧道，导致施工环境的恶化，给隧道施工和造价控制造成一定的难度。此文以蒙河铁路工程毛坡梁、三家寨等3座高温隧道为研究样本，分析形成高温的成因。并针对这些高温因素和具体施工条件，提出加强隧道内通风、采用冰制冷系统、设置降温屋等措施降低掘进面附近的施工环境温度，来保证施工质量和计划进度。同时，对采取有效降温措施下的主要投资构成进行分析，以便形成合理而准确的单价分析。     

福厦铁路玉塘洋特大桥台尾路基垮塌原因分析及处理措施

东南沿海地区滨海软土特别发育,临时工程的不当设置,将影响铁路工程路基的稳定。结合福厦铁路玉塘洋特大桥台尾路基垮塌实例,对垮塌原因进行分析,提出了以桥代路方案,实施结果保证了路基工程的稳定性,和福厦铁路施工的顺利推进。     

对海事依法行政有关问题的思考

中国的改革开放是一场史无前例的“摸着石头过河”的大试验。依法行政也有“摸着石头过河”的感觉。马列主义是关于实践的科学,从实践的角度来认识与思考依法行政,对提高依法行政水平更具有现实性。     

风险管理在某EPC项目中的应用

设计单位作为工程设计、采购、施工的总承包商,对建设工程的质量、安全、工期、造价、环保等全面负责,比传统的工程设计扩大了责任范围,增加了管理难度,同样承担了更多的风险.那么,如何在建设过程中对可能存在的风险进行识别和评价,此文从设计、采购、施工等方面进行论述和评价.根据评价等级,对不可接受的风险,提出可采取的应对措施,以期达到风险管理的目的.     

How and why do men and women differ in their willingness to use automated cars? The influence of emotions across different age groups

Current research on willingness to use automated cars indicates differences between men and women, with the latter group showing lower usage intentions. This study aims at providing a first explanation of this effect. Research from other fields suggests that affective reactions might be able to explain behavioral intentions and responses towards technology, and that these affects vary depending on age levels. By examining a sample of 1603 participants representative for Germany (in terms of biological sex, age, and education) we found evidence that affective responses towards automotive cars (i.e., anxiety and pleasure) explain (i.e., mediate) the effect of biological sex on willingness to use them. Moreover, we found that these emotional processes vary as a function of respondent age in such a way that the differential effect of sex on anxiety (but not on pleasure) was more pronounced among relatively young respondents and decreased with participants’ age. Our results suggest that addressing anxiety-related responses towards automated cars (e.g., by providing safety-related information) and accentuating especially the pleasurable effects of automated cars (e.g., via advertising) reduce differences between men and women. Addressing the anxiety-related effects in order to reduce sex differences in usage intentions seems to be less relevant for older target groups, whereas promoting the pleasurable responses is equally important across age groups.     

Options for reducing noise from roads and railway lines

The fundamental noise generation mechanisms of road and rail vehicles are discussed with attention to noise abatement measures. Based on an evaluation of publicly available tire noise data and the European road traffic noise emission model CNOSSOS, it is shown that on the road side there is a significant noise reduction potential in the usage of low-noise tires. From a three months measurement campaign a noise model was derived to predict the maximal sound pressure level of heavy duty vehicles during a pass-by in 7.5 m distance with the parameters vehicle speed and number of axles. With help of recently published information about external costs caused by heavy duty vehicles and the noise prediction tool, a model was developed to derive a money equivalent that can be used as a bonus/malus in a heavy duty vehicle fee. As a measure at the infrastructure, the installation of low-noise pavements is an effective, durable and economically attractive measure. Recent experiences with different technologies from all over the world are compiled and evaluated. On the rail side, an overview of the possible noise reduction strategies is given, followed by a discussion of the current policy and legislation in the EU and on the national level of different European countries.