A new type of composite support structure is a cross combination of steel pipe and Hat type steel sheet pile, PHC support structure for short. It has the advantages of large section modulus, stiffness, and a good steel sheet pile sealing effect. Using ABAQUS to carry out a three-dimensional finite element simulation of the foundation pit excavation. From the dimensions of steel pipe, Hat steel sheet pile, and other aspects of the excavation supporting effect analysis.
To ensure the safe operation of external floating roof (EFR) tanks, it is important to conduct risk assessments for fire and explosion accidents. In this study, we develop a modified analytic hierarchy process to overcome the subjectivity in traditional analytic hierarchy analysis, improved analytic hierarchy process, and fuzzy fault tree analysis. We propose a parameter with a correction factor: the role of the parameter in the model can be gained from further modifying the structural importance of each basic event so as to overcome the subjectivity in traditional analytic hierarchy analysis, improved analytic hierarchy process, and fuzzy fault tree analysis. The judgment matrix for the analytic hierarchy process is constructed based on the modified structural importance of each basic event in a fault tree. The weight factor for each index to the top goal, combined with the fuzzy comprehensive assessment method, is adopted to conduct risk assessments for the fire and explosion accidents of EFR tanks.
为探究固化土加固对于海上风电大直径单桩基础水平承载特性的影响,以江苏如东H4#海上风电场工程为背景建立了固化土加固海上风电大直径单桩基础的有限元计算模型,研究了固化土加固前后单桩基础的水平承载特性,分析了固化土强度参数对单桩基础水平承载特性的影响.研究结果表明:利用固化土加固单桩基础可显著改善桩基的水平承载特性,桩基的水平承载力可提高147％;桩身位移对于固化土粘聚力的变化较敏感,内摩擦角的变化对于桩身位移的影响则较低.
局部冲刷是海上风电工程中常见的现象.目前,工程中对于海上风电基础冲刷防护仍以抛石措施为主,然而该措施存在防护效果差、后期维护费用高的缺点.结合如东海上风电工程,对固化土加固海上风电桩基础冲刷坑的抗冲刷过程进行了分析.根据扫测结果对桩基础冲刷坑形态进行总结分类,并针对性地提出了四种防护方案,进而对固化土施工方案和施工工艺进行了总结.采用多波束对固化土防护效果进行了检测,扫测结果显示固化土防护后的桩基础周围基本保持平整状态,未见明显的冲刷现象,说明固化土防护层能够抵抗高速水流的冲刷,可作为传统抛石措施的替代方案.研究可为海上风电基础冲刷防护工程提供参考.
吉林市九站松花江铁路大桥桥区河道地形起伏大,枯水期航道尺度不足,水位落差集中,存在明显的陡比降.加之桥区临时建筑物未拆除,导致过水断面剧烈收缩,形成急流,严重碍航.采用二维水流数学模型对整治方案进行了计算分析.结果表明:扩大卡口断面和航槽疏浚不能有效解决该河段陡比降的问题,而采用复式断面对桥下游边滩进行开挖可较好地调整水流流态,降低流速,消除陡比降,通航条件较好,可为桥区河段急险滩整治提供借鉴.
