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本文基于CIVIL 3D建立某海外港口防波堤模型,解决在原有防波堤基础上新建防波堤后的工程量计算问题。本文将介绍整个建模过程和思路,通过软件分析得到新建防波堤的精准工程量,并通过构建原有防波堤BIM模型对比实际已建防波堤的工程量验证模型的正确性,最后通过对比传统防波堤计算方法表明基于CIVIL 3D软件的BIM建模更加精准有效。 相似文献
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This study examined the network sensor location problem by using heterogeneous sensor information to estimate link-based network origin–destination (O–D) demands. The proposed generalized sensor location model enables different sensors’ traffic monitoring capabilities to be used efficiently and the optimal number and deployment locations of both passive- and active-type sensors to be determined simultaneously without path enumeration. The proposed sensor location model was applied to solve the network O–D demand estimation problem. One unique aspect of the proposed model and solution algorithms is that they provide satisfactory network O–D demand estimates without requiring unreasonable assumptions of known prior information on O–D demands, turning proportions, or route choice probabilities. Therefore, the proposed model and solution algorithms can be practically used in numerous offline transportation planning and online traffic operation applications. 相似文献
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A. F. Beckenham 《运输评论》2013,33(3):267-279
The review undertaken in this paper shows how, at the beginning of 1988, nation‐states of the world allocated ministerial responsibilities for the important function of transport. A total of 118 countries are examined, compared with 111 in 1982 (Transport Reviews, Vol. 2, No. 4) and 115 in 1985 (Transport Reviews, Vol. 5. No. 1). The analysis reveals an increase in the number of ministers solely responsible for one mode of transport, and notes an increase in the number of designated ministers for tourism. The paper goes on to examine the two main duties of ministers of transport: safety and economic regulation; and of the increasing need for closer international co‐operation as new transport technology, the growing demand for travel and expanding world trade make our world ‘an even more local village’ in the decades to come. 相似文献
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层状岩层的横观各向同性使得振动波在岩层中沿着不同方向传播时,质点的振动特性有着一定的差异。以我国西南地区某高海拔山区单向公路隧道的全断面爆破掘进为研究背景,利用FLAC 3D软件对构造应力场中均质围岩及倾角不同的层状围岩在隧道爆破开挖过程中的变形、振动速度进行研究。研究结果表明,隧道开挖爆破后,洞周岩体变形不对称式分布,左、右拱腰部位变形最大,均质围岩洞周各部位变形在5种模型中相对较小;爆源距相同时,层状围岩左、右测点的x向振动速度均大于上、下测点的z向振动速度;断层破碎带、层理结构面对于振动波的传播既有消振又有聚振的作用,与断层破碎带和层理结构面的产状、空间关系及振动波相对结构面入射角度有关。 相似文献
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An extensive body of theoretical and empirical work has been undertaken in the UK since the middle of the last century on the estimation of values of safety for use in the appraisal of proposed transport projects, particularly road and rail. This research has focused largely on ‘willingness-to-pay’ based values in order to measure the strength of the travelling public's preference for marginal improvements in transport safety, relative to consumption of other goods and services. In terms of practical policy making, the research has resulted in a set of values for the prevention of statistical fatalities and non-fatal injuries that are applied not only in transport safety decision making, but also in other public sector contexts. This paper summarises the main findings of this research. 相似文献
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