排序方式： 共有33条查询结果，搜索用时 15 毫秒
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韩国世越号打捞是世界上首次利用托底钢梁原状态整体起吊难船出水的工程。客滚难船装载的货物容易在沉没后发生移位,上层建筑长时间沉没海底后发生泥沙淤积导致难以准确估计整船的重量重心及浮力浮心的位置。利用水池模型试验和数值计算两种方法分别对大型浮吊船单臂架打捞法和双驳船抬吊打捞法进行了难船姿态受重心位置偏移的敏感性分析。水池模型试验中发现,用大型浮吊船单臂架打捞法,世越号的姿态受其重心位置偏移非常敏感,容易发生侧翻;而用双驳船抬吊打捞法,世越号的姿态受其重心位置的影响非常有限,难船和抬浮驳船都可以保持一个较好的姿态。对比水池模型试验的结果,由于难以计及托底钢梁的翘动和滑动现象,数值计算中得到的难船起吊姿态值偏小。双驳船抬吊打捞法被选为打捞世越号的施工方案,其对难船重心位置偏移不敏感的特性得到了现场实证。这个特点为世越号的成功打捞出水起到了关键作用。 相似文献
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The dynamic factor is the ratio of the maximum dynamic load to the static load acting on the wire ropes between the boom of a floating crane and a cargo. In this paper, the dynamic factor is analyzed based on dynamic simulations of a floating crane and a cargo, considering an elastic boom. For the simulation, we designed a multibody system that consists of a floating crane barge, an elastic boom, and a cargo connected to the boom through wire ropes. The dynamic equations of motion of the system are based on flexible multibody system dynamics. Six-degree-of-freedom motions are considered for the floating crane and for the cargo, and three-dimensional deformations for the elastic boom. The hydrostatic force, the hydrodynamic force, the gravitational force, and the wire rope forces are considered as external forces. The dynamic factor is obtained by numerically solving the equation. The effects of the elastic boom on heavy cargo lifting are discussed by comparing the simulation results of an elastic boom and a rigid boom. 相似文献
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近年来,国内兴起了大力发展半潜式起重平台的势头,系泊系统的设计与优化是该类型平台开发中的关键问题之一。采用时域方法对半潜式起重平台系泊系统进行耦合动力分析,研究系泊系统主要参数对其动力响应特性的影响,并给出主要参数的设计优化流程,在此基础上,以能够满足安全校核且性能较优的系泊方案为目标,对该半潜式起重平台的系泊系统进行优化设计,并研究单根系泊缆发生破断对整个系泊系统的影响。结果表明:基于主要参数对系泊性能的影响规律,经优化设计得到的系泊方案,预留的安全欲度适中,能够保障半潜式起重平台在恶劣海况下的生存能力,同时具备较好的经济性。 相似文献
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The probability of crane living in reedy wetlands can reach 100%, at the same time, the area of reed, the water level and adjacent water area are main factors which control the crane's habitat selection. We all know that all these factors are spatially heterogeneous. For the Xianghai wetland safety and to protect the Xianghai wetland habitat of crane, this paper has mainly identified a solution to these problems. The wetland information is extracted from the TM images, which reflect the whole wetland landscape and are very important for both quantitative analysis of remote sensing observation of the earth system and positioning analysis in GIS database that is automatically extracted from DEM. The DEM for Xianghai characteristics of topography is created. On the basis of the GRID SUBMODULE, applying the GIS spatial overlay analysis, the relationship between the water level and the reed area below the water level and the rating distribution maps of reed area above water level is established. When the water level reaches the altitude of 165 m, the reed area, 981.2 ha is maximum, i.e., the water level of 165 m is the optimal. 相似文献
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小湾水电站地下厂房岩锚梁现场试验研究 总被引：1，自引：0，他引：1
小湾水电站地下厂房是目前世界上最人的地下厂房之一，采用了岩锚吊车梁结构形式，厂房开挖跨度和高度分别为28．30m和79．88m。由于岩锚梁通过两条宽度为0．5～8．5m的陡倾断层，其施工期与运行期的稳定性成为关注的问题之一。在厂房洞室群的尾水闸门室中，选择具有相似工程地质条件的区域进行了现场模型试验研究，包括主要监测仪器的布置和加卸载过程设计，并对监测结果进行了分析。模型试验表明岩锚吊车梁承载能力满足设计要求，安全性有保障。 相似文献
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向海自然保护区鹤类生境优化水位的模拟 总被引：5，自引：0，他引：5
芦苇面积，苇下水位变动和邻近水域大小等是影响鹤类生境选择的重要因子，通过建立向海地区的数字高程模型（DEM），将其与从遥感影像上获取的向海湿地景观信息在ARC／INFO模块下进行空间叠加分析，建立了水位与芦苇分布的动态关系。通过模拟得出；当湿地水位达到165m时，鹤类可选择的生境面积最大，为981.2hm^2。此外，本文还模拟了不同水位以上芦苇面积的等级分布规律。该模拟结果对于向海自然保护区鹤类生境的优化管理及主要供水源向海水库的科学管理具有重要的参考价值。 相似文献