Gauging interventions for sustainable travel: A comparative study of travel attitudes in Berlin and London

So-called ‘soft’ policy instruments that respond to the psychological aspects of travel are regularly acknowledged as necessary complements to ‘hard’ infrastructure investments to effectively promote sustainable travel in cities. While studies investigating subjective orientations among travellers have proliferated, open questions remain including the role of recent technological advances, the expansion of alternative mobility services, locally specific mobility cultures and residential selection. This paper presents the methods, results and policy implications of a comparative study aiming to understand mobility attitudes and behaviours in the wider metropolitan regions of Berlin and London. We specifically considered information and communication technology (ICT), new types of mobility services such as car sharing, electric cars and residential preferences. In each region, we identified six comparable segments with distinct attitudinal profiles, socio-demographic properties and behavioural patterns. Geocoding of the home address of respondents further revealed varying contextual opportunities and constraints that are likely to influence travel attitudes. We find that there is significant potential for uptake of sustainable travel practices in both metropolitan regions, if policy interventions are designed and targeted in accordance with group-specific needs and preferences and respond to local conditions of mobility culture. We identify such interventions for each segment and region and conclude that comparative assessment of attitudinal, alongside geographical, characteristics of metropolitan travellers can provide better strategic input for realistic scenario-building and ex-ante assessment of sustainable transport policy.     

Measuring the car ownership impact of free-floating car-sharing – A case study in Basel,Switzerland

Free-floating car-sharing schemes operate without fixed car-sharing stations, ahead reservations or return-trip requirements. Providing fast and convenient motorization, they attract both public transport users and (former) car-owners. Thus, their impact on individual travel behavior depends on the user type. Estimating the travel behavior impact of these systems therefore requires quantitative data. Using a two-wave survey approach (shortly after launch of the scheme plus one year later) including travel diaries, this research indicates that (due to their membership) 6% of the free-floating car-sharing customers reduce their private vehicle ownership. Moreover, the results suggest that free-floating car-sharing both complements and competes with station-based car-sharing.     

新型防爆地震仪在瓦斯隧道超前地质预报中的应用

为提高瓦斯隧道地震波反射法超前地质预报现场作业的安全性及可操作性，介绍一种新型防爆地震仪的主机结构、主板设计、本安电源及远程控制等核心技术，同时介绍检波器气囊耦合技术；最后采用36道防爆地震仪和高精度三分量地震检波器气囊耦合装置，在重庆渝北至四川广安高速公路华蓥山隧道进口右线K24+314掌子面处进行超前探测试验，其采集的地震记录质量高，气囊耦合方式现场操作方便快捷。经过与传统的国外TSP仪器及钢管锚固剂耦合方式对比分析，充分说明采用国内的矿用防爆地震仪及其配套研制的检波器气囊耦合装置完全适用于各类瓦斯隧道地震波反射法超前地质预报工作，且能使地震波反射法实现本质安全。     

Estimating the ride quality characteristics of vehicles with random decrement analysis of on-the-road vibration response data

This paper describes the application of a practical analytical technique based on the random decrement method to estimate the rigid sprung mass dynamic characteristics (frequency response function) of road vehicles using only vibration response data during constant-speed operation. A brief history and development of the random decrement technique is presented, along with a summary of work undertaken on optimal parameter selection to establish the random decrement signature. Two approaches to estimate the dynamic characteristics from the random decrement signature are described and evaluated. A custom, single-wheeled vehicle (physical quarter car) was commissioned to undertake a series of on-the-road experiments at various nominally constant operating speeds. The vehicle, also instrumented as an inertial profilometer, simultaneously measured the longitudinal pavement profile to establish the vehicle's actual dynamic characteristics during operation. The main outcome of the paper is that the random decrement technique can be used to provide accurate estimates of the sprung mass mode of the vehicle's dynamic characteristics for both linear and nonlinear suspension systems of an idealised vehicle.     

规划盐泰锡常宜铁路长江桥位线路方案研究

针对盐泰锡常宜铁路越江问题,分析区域沿江城市规划、区域过江通道、水文、地质特征与河势,提出长江桥位线路方案。最后,通过长江特大桥建桥条件及引入泰锡常地区条件等全面系统分析,选出江阴铁路大桥方案为合理方案。     

Experimental and numerical analysis of a tanker side panel laterally punched by a knife edge indenter

The paper presents finite element simulations of a small-scale stiffened plate specimen quasi-statically punched at the mid-span by a rigid indenter, in order to examine its energy absorbing mechanisms and fracture. The specimen, scaled from a tanker side panel, is limited by one span between the web frames and the stringers. The paper provides practical information to estimate the extent of structural damage within ship side panels during collision accidents. Moreover, the results of this investigation should have relevance to evaluate grounding scenarios in which the bottom sustains local penetration. This is possible since the structural arrangement of the double hull and the double bottom of tanker vessels is very similar. The experimentally obtained force–displacement response and shape of the deformation show good agreement with the simulations performed by the explicit LS-DYNA finite element solver. The numerical analysis includes aspects of particular relevance to the behaviour of ship structures subjected to accidental loads which could give rise to difficulties in interpreting finite element calculations. In particular, the paper comments on the material nonlinearities, the importance of specifying the precise boundary conditions and the joining details of the structure. The considerable practical importance of these aspects has been the focus of attention in previous publications of the authors which evaluate the experimental-numerical impact response of simple ship structural components, such as beams and plates. Therefore, this paper uses the definitions proposed in those references to evaluate its applicability in the scaled tanker side panel, as an example of a more complex ship structure.     

CBR-V法矿质集料骨架嵌挤评价指标CBRmax求解的试验研究

CBR-V矿料级配设计方法是基于矿料特征和矿料级配特征的一种设计方法,矿料的特征及其级配的组成非常复杂,要考虑其对合成级配的影响困难较大,所以通过试验数据反映矿质集料的特征状况。由于在试验中集料的不同特征得到了综合的体现,所以可以认为试验中考虑了集料的各种特征,是一个能够体现集料全部特征的设计方法。通过32组正交试验,获取的CBR_max相比CBR-V法获取的CBR_max小7.6%,说明通过CBR-V法获取的CBR_max值更接近CBR_max。分析表明通过CBR-V法获取CBR_max是可行的,过程工作量更小,效率更高;其采用的强度传递理念是正确的且具有客观唯一性的特点。     

BIM 技术在市政改建道路管线综合中的应用研究

随着城市的快速发展，过去规划及设计的道路已经不能满足日趋增长的交通需求，在市政道路改建工程中，管线综合相比新建工程更加复杂，与传统二维设计相比，BIM技术在市政管线综合应用中具有更多优势。利用BIM技术的三维可视化信息、信息共享、碰撞检查等功能对管线综合设计方案进行优化，减少了项目的设计变更，保证项目进度并节约了项目成本。     

土岩交错地层隧道爆破施工的振动响应及空洞效应分析

以汕湛高速揭博段水墩隧道为工程背景,运用数值模拟计算的方法,建立上软下硬地层下爆破振动的有限元计算模型,对爆破荷载作用下上部初期支护和围岩的振动响应及空洞效应进行研究。结果表明： 1）掌子面下部基岩爆破施工的振动荷载主要通过支护结构传递给拱顶围岩,而掌子面上部前方围岩（未成洞区）和后方围岩（成洞区）振动分布并不对称,其中成洞区围岩的振动速度和振动范围远大于未成洞区,说明上软下硬地层隧道爆破振动存在空洞效应; 2）成洞区单向约束是造成振动加剧的根本原因,围岩振动的纵向最不利位置为掌子面后方约2 m处,径向为软硬交界结构面与隧道外轮廓的切点处; 3）振动方向以径向为主,即拱顶围岩振动以竖向振动为主,初期支护拱脚以水平振动为主; 4）距离掌子面1倍(洞径)范围的拱顶围岩及初期支护拱脚是控制爆破振动的关键部位。     

引汉济渭秦岭隧洞高磨蚀性硬岩TBM滚刀磨损试验研究

引汉济渭工程秦岭输水隧洞TBM掘进施工在试掘进段因遭遇高磨蚀性硬岩地层,滚刀发生严重磨损,致使施工进度严重滞后。为降低刀具磨损,节约施工成本,加快施工进度,必须对刀具磨损进行准确预测。针对高磨蚀性地层,开展滚刀磨损预测研究; 通过课题组前期研究结果,建立滚刀磨损理论预测模型; 通过室内实验,建立滚刀磨损实验预测模型; 通过现场试验,对室内实验模型及课题组前期研究建立的理论预测模型进行验证。结果表明,实验预测结果具有较高的准确性,相对误差在10%以内。