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对黄山市中心城区现状防洪能力进行了分析 ,认为现有防洪能力与城市地位、社会经济发展极不相称 ,防洪工程作为基础设施明显落后于城市发展。文中就如何提高城市的防洪标准 ,提出了治理对策和措施。 相似文献
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皇岗-落马洲大桥是连接深圳-香港的重要交通设施,为使大桥能满足深港两地客货运输的要求,需保证结构安全度符合内地及香港两地相关规范。本文分别按照内地及香港规范要求计算内力并进行比较,得到合理的设计内力值,为结构设计提供了可靠的依据。 相似文献
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该研究全面地调查了铀矿石集散地放射性污染状况及动态,分析测定了久长车站及周围环境土壤、水源、粮食作物中铀、钍、镭及总α、总β放射性水平、站内外地表β、γ辐射强度,劳保用品、运输车辆的污染状况,水源及空气中氡的浓度。基本摸清了久长车站及周围地域的放射性水平、分布规律、动态变化及采取防护措施的效果。 相似文献
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从航运实务出发,结合实践中承运人关于责任期间所遇到的问题,依照我国《海商法》第46条关于承运人责任期间的规定,就如何保障《海商法》第46条充分适用,提出了几点建议。 相似文献
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本文结合作者有关 CAD技术的开发与应用实践 ,从几个方面讨论了如何评价或开发一套适于道路及立交设计的 CAD系统。 相似文献
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This paper describes a logit model of route choice for urban public transport and explains how the archived data from a smart card-based fare payment system can be used for the choice set generation and model estimation. It demonstrates the feasibility and simplicity of applying a trip-chaining method to infer passenger journeys from smart card transactions data. Not only origins and destinations of passenger journeys can be inferred but also the interchanges between the segments of a linked journey can be recognised. The attributes of the corresponding routes, such as in-vehicle travel time, transfer walking time and to get from alighting stop to trip destination, the need to change, and the time headway of the first transportation line, can be determined by the combination of smart card data with other data sources, such as a street map and timetable. The smart card data represent a large volume of revealed preference data that allows travellers' behaviour to be modelled with higher accuracy than by using traditional survey data. A multinomial route choice model is proposed and estimated by the maximum likelihood method, using urban public transport in ?ilina, the Slovak Republic, as a case study 相似文献
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In the light of semi?rigid material as base course for perpetual asphalt pavement,the bearing capacity and fatigue life of asphalt pavement with semi-rigid base cause and different asphalt layer's thickness were computed with BISAR30 after chosen typical pavement The impact of thickened layer on the stress of the semi?rigid base,the dry shrinkage and temperature shrinkages of the material were analyzed,and its adaptability as base for perpetual pavement was studied The result shows that (1) under the same load,with thickening of the asphalt layer,the compressive stress on the top and the tensile stress at the bottom of the semi?rigid base decrease obviously and the fatigue life of
the base increases substantially; (2)the impact of temperature and humidity on the
semi-rigid base is remarkably weakened,which leads to the fractures,erosion and reflecting cracks of the semi?rigid base to be controlled effectively 相似文献
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四川绵阳飞云大桥的主桥系三跨系杆拱桥 ,横向设两根拱肋 ,构成“双弓体系”。本文介绍该桥的结构设计及施工要点。 相似文献