可靠性分析在边坡灰色聚类问题中的应用

选取了“过程降雨量”与“最大地震震级”作为可靠性分析的目标因素,将其可靠度引入到传统BP神经网络预测边坡灰色聚类问题的方法中,将5个典型边坡中的3个作为预测样本,对其余2个进行分析,得到了2个目标因素单独作用于边坡时边坡的可靠度以及在选取的9个因素共同作用下较精确的预测结果.     

圆柱桩群局部冲刷特性试验

通过在宽长水槽中进行的单向恒定均匀流作用下,不同桩群、不同流速或不同水深情况下的圆柱桩群局部动床冲刷对比试验研究,分析试验后水槽地形变化的资料发现：圆柱桩群局部冲刷非常复杂,圆柱桩群的存在极大地改变了原有的水沙运动状态,加剧了桩群所在底床泥沙的冲淤。圆柱桩群对其所在底床冲淤影响特性不能只用桩群阻力简单解释,而与圆柱排列形式关系最为密切、影响也最大,水流流速及水深的影响实际通过圆柱桩群对流场改变的性质及程度来反映。     

集群产业内在关联方式及优化分布模型探析

本文在分析和梳理集群产业不同关联方式的基础上,运用多学科的理论和方法,对集群产业在一定区位上的分布进行了优化设计,为区域主导产业的选择和布局提供技术、政策支持,以促进产业集聚的有效发生和持续发展。     

沥青混凝土路面预防性养护对策选择

对广东省某高速公路进行路况调查后,根据调查结果,研究预防性养护对策选择流程、养护路段划分指标和方法。采用车辙深度、横向裂缝长度和路面抗滑性能指数三指标,使用动态聚类法,划分预防性养护路段。得到了预防性养护对策选择的流程,给出了聚类分析法划分路段的过程和结果。结果表明,采用该流程进行养护措施的选择,科学性、客观性强;聚类分析法用于高速公路养护路段的划分可取得良好的效果。     

Numerical analysis of vortex-induced vibration on a flexible cantilever riser for deep-sea mining system

The flexible cantilever riser, as a special form of the marine riser, can be encountered in a deep-sea mining system, where the bottom of the long vertical lifting pipeline is connected with the intermediate warehouse. The main objective of this paper is to investigate the effects of the bottom weight caused by the intermediate warehouse and the flow speed on the dynamic responses of the cantilever pipeline. A quasi-3D coupling algorithm based on the discrete vortex method and finite element method is employed to calculate the unsteady hydrodynamic forces and vortex-induced vibrations of this pipeline in the time domain, respectively. We first simulate the VIV of a long flexible riser with two fixed ends in a stepped flow to validate the feasibility of the present method. Then, systematic simulations of cross-flow VIV of the cantilever riser are carried out under a wide range of bottom weights and different current speeds. The number of the vibration mode shows the decreasing tendency with the increase of the bottom weight. In a certain range of the weight, the number of the dominant mode remains unchanged, while the vibration amplitude declines with increasing weight. An amplitude jump phenomenon can be observed when the transition of the dominant mode in two contiguous mode clusters occurs. Moreover, the higher-order modes are excited with the increase of the current speed.