长江中游太平口水道河床演变趋势与模型预测成果对比分析

分析了荆州长江大桥所在沙市河段太平口水道演变特征,并同模型试验预测的三峡水库蓄水运用后桥区河段演变趋势进行对比分析。实践表明,利用模型试验手段对该河段河床演变趋势预测是成功的,为其航道整治方案的制定和工程实施顺序提供了科学依据。     

长江宜宾—重庆航道浅滩整治措施分析

2003年以来长江宜宾—重庆段航道陆续按Ⅲ级航道标准进行了系统建设。建设过程中结合具体河势及碍航情况采取了单纯疏浚,顺坝与潜坝结合,疏浚配合丁坝、丁顺坝,疏浚、筑坝、护底配合等浅滩治理措施。结合实例对浅滩整治措施和效果进行分析。     

嘉陵江草街—北碚段航道整治效果及补水需求分析

嘉陵江草街至河口段整治工程分期实施,部分滩段整治效果未及预期,通航条件仍然较差。针对嘉陵江草街至北碚段航道枯水期斑鸠背、二郎滩等滩段出浅碍航的问题,结合深度平均的平面二维水力学数值模拟和航道通航水流条件原型观测,分析研究河段各滩险的碍航特性及整治效果,提出重点滩段达到航道维护尺度的流量要求及相应保证率。研究结果表明:嘉陵江草街至北碚段航道近年来虽进行了系统整治,航道通航水流条件得到一定的改善,但受逐年地形变化影响,航槽内冲淤变化显著,目前已不能满足Ⅲ级航道尺度要求;在现状条件下,满足Ⅲ级航道尺度要求的草街最小下泄流量约为1 391 m~3/s。     

长江中游江口水道支汊航道开发利用可行性分析

随着长江沿江可利用岸线资源的日益减少,一些复杂条件下的长江岸线急需要开发出来,这其中很大一部分需要以支汊可通航作为基础。现今倡导绿色水运、和谐水运,对长江干线支汊航道进行开发利用可行性分析不仅是为沿江经济服务,更是保护航道资源的需要。针对有强烈开发需求的江口水道,通过河床演变分析、航道条件核查、开发利用可行性分析等手段进行了航道等级与维护尺度研究,并进一步预测了支汊开通后带来的社会经济价值,具有很强的实用价值和广阔的应用前景。     

Do people drive safer when accidents are more expensive: Testing for moral hazard in experience rating schemes

Using individual policies and claims data from the Croatian mandatory motor insurance we test the theoretical proposition that under moral hazard, experience rated pricing scheme should generate the negative state dependence in claims, i.e. that drivers should drive more safely after they had an accident. The empirical challenge in these tests is to disentangle the state dependence from unobserved heterogeneity. We propose a simple approach based on the explicit reliance on the cost of future accidents function which is used to filter out the pure incentives effect, whereas the bonus-malus scale is used to control for pure heterogeneity. Our results confirm the existence of negative dependence in claims indicating the presence of significant moral hazard effect. Increasing a 3-year cost of having an accident by approximately US$20 decreases the probability of having an accident by 6.5%.     

Environmentally appraising different pavement and construction scenarios: A comparative analysis for a typical local road

The aim of this work is to carry out a comparative analysis of environmental impacts for different scenarios of a typical local road. Life Cycle Assessment (LCA) is the modeling tool used to quantify and characterize comparative environmental impacts. In carrying out this specific application of the LCA, different road construction techniques were considered with regards to the whole structure and compared in order to identify the best alternative in terms of environmental sustainability.So far, in fact, typical LCA frameworks of roads have focused on recycled materials for pavement layers only, thus neglecting study of the materials used in the embankment or in the subgrade. In this study, these materials were included too, in order to prove the environmental benefit of using a sustainable technique such as in situ stabilization of fine soils with lime (typically dumped clayey soils) in order to reduce the need for virgin material for embankment and subgrade construction.When using different percentages of recycled materials (such as reclaimed asphalt pavement – RAP) in the bituminous layer or in the foundation, the analysis of the functional unit studied shows a significant reduction of energy consumption and pollutant emissions mainly due to transportation of materials involved, in this way increasing the environmental performance of the road.Another important consideration is that the use of fine soils stabilized with lime “in situ”, instead of dumping it, not only is a good technical solution for improving soil mechanical properties, but it also produces a reduction of energy consumption and of pollutant emissions. It is noticeable that this technique results in a significant reduction of pollutant emissions due the transportation of involved materials, increasing the environmental performance of the road.     

郁江贵港城区河段河道演变分析

郁江的河道演变对河流的堤防安全、河势稳定、防汛抢险等影响重大。以郁江贵港市区河段作为研究对象，通过实测资料，分析了研究河段的历史演变，对24个典型断面的断面特征和河床演变的趋势进行分析。结果表明：研究河段在近30 a河槽变化不大，河势相对较为稳定，河道各个断面有冲有淤且变化幅度较小；在现有水沙条件下，未来河段将呈缓慢淤积的趋势，贵港和桂平航运枢纽对河势及冲淤变化影响不大。     

Structural relationships among shipper’s perception,value, and choice intention of Korea–China train ferry service

ABSTRACT

The logistics environment between China and Korea has been changing rapidly in line with the ‘Go West’ policy of international trade and logistics area. The policy includes the BRI, Western Development Strategy, and Korea–China FTA. Against this background, the Korea–China train ferry (KCTF) is being newly illuminated as an alternative mode to cope with the logistics environment between Korea and China. One of the key success factors of the KCTF depends on, among others, shippers’ perception, which will affect the choice and the successful operation of the KCTF. From this perspective, this paper develops seven hypotheses based on the Theory of Reasoned Action (TRA) and Technology Acceptance Model (TAM). We test these hypotheses using Structural Equation Modeling (SEM) to explore the structural relationship between shippers’ behavioral beliefs influencing the perceived usefulness, the attitude toward and intention to choose the KCTF. The test results confirm that among the behavioral beliefs, transport accessibility in association with an efficient network of inland roads and railway networks is an important prerequisite. In addition, we verified a high statistical significance in the structural relationships among perceived usefulness, the attitude toward and the intention to choose the KCTF.     

基于SWOT分析法的川江滚装船的发展战略研究

本文采用SWOT法从优势、劣势、机会和威胁四个方面对川江滚装船在综合运输系统的地位进行定位，并从政府主管机关、行业中介组织、市场主体船东自律与潜力挖掘三方面提出一些建议。     

长江流域水质的综合评价与预测

长江流域水质演变过程可看成是一个具有多节点,向下流关联的复杂网络系统。本文运用统计学的统计推断原理及复杂系统理论,对长江近两年的水质情况作定量的综合评价。