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实验研究了双桩并列和串列时不规则波浪作用于各桩上的横向力(同步测定了正向力);分析研究了横向力的时域特性和频域特性,给出了各桩的升力系数和横向力群桩系数随相对桩距和KC数的变化规律,还探讨了横向力和正向力的合力与正向力之比以及合力系数的变化规律。 相似文献
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随着海上风电的蓬勃发展,如何提高沉桩质量与施工工效是需要研究的问题。唐山乐亭菩提岛海上风电场300MW 示范工程作为渤海湾第一个海上风电场,施工前期通过对渤海湾水文、地质分析,对沉桩相关设备、施工流程、施工质量控制点等的分析,克服了水深、涌浪大、地质条件差、钢管桩长等难点,确保了15个承台共120根钢管桩的沉桩进度与质量,得到了业主的好评。文章总结优化了渤海湾海上风电场沉桩相关技术与控制难点,为后续渤海湾海上风电场沉桩施工提供了重要施工经验与保障。 相似文献
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介绍了广州港新沙港区板桩码头主要内力计算方法及常用软件,结合设计过程、工程地质情况、现场实际施工情况,着重从受力合理性、施工便利性、节省造价方面,对提出的钢板桩方案、钢管板桩方案进行比较分析,确定了钢管板桩结构更合理,并对优势进行总结。研究表明相对于钢板桩结构,钢管板桩结构在抗弯、抗变形、拉杆拉力和锚碇墙稳定性、对复杂地基(软弱土层较厚、岩层标高较高的地基)适应性、兼顾桩基基础、施工速度等方面更具备优势,且钢管板桩结构可更好的适应码头的大型化和深水化发展,在类似工程设计中可优先采用钢管板桩结构。 相似文献
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本文主要归纳了基于Morison方程求解小尺度桩柱的水动力系数方面的研究成果。分别从单桩柱和群桩两个方面对水动力系数的研究成果,包括纯波、波流混合、横向力、直立桩柱、倾斜桩柱、复杂结构桩柱、粗糙度等进行了阐述,给出了在波流条件下水动力系数的变化规律;归纳了当前水动力系数的求解方法;介绍了在水动力系数的物模实验、数值仿真以及实验数据处理方法上的研究进展,并提出了相关研究的建议。 相似文献
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考虑桩土作用独桩海洋平台横向振动特性研究 总被引:5,自引:0,他引:5
采用动Winkler弹性地基梁模型模拟桩土问动力相互作用,并考虑了流体与桩问相互作用,通过组合成层土中、水中桩单元的刚度阵,推得了独桩海洋平台连续系统横向振动的动刚度阵及在波浪力作用下平台甲板处的频率响应函数,进而求得了在确定性波浪力及随机波浪力作用下桩身任意点的位移响应。最后,通过算例研究和分析了在随机波浪力作用下成层土参数、甲板上重量及冲刷淘深等因素对平台振动响应的影响。 相似文献
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基于P-Y曲线法考虑桩土相互作用的高桩结构物分析 总被引:12,自引:0,他引:12
PY曲线法是一种非线性地基反力法,可用于分析横向荷载作用下桩结构物,尤其在分析有较大变位的桩结构物时,有许多突出的优点。本文就PY曲线法分析横向力作用下的高桩结构物的实施方法、特点进行了研究,编制了相应的程序,结合算例给出一些供工程设计人员参考的结论。 相似文献
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螺旋桩芯劲性复合桩(helix stiffened cement mixing pile,简称HSCM桩)是一种新型复合桩,其成桩工艺会对桩身及其承载性能有较大影响。为验证HSCM桩在软黏土中同步旋进注浆工艺的可行性,并研究其成桩参数对抗压承载性能的影响,设计了2组缩尺模型试验,包括不同叶片数量与钻进速度的HSCM桩与对比螺旋桩。通过在高岭土制备的软黏土中成桩,并进行抗压承载性能及桩身几何尺寸测试,分析HSCM桩的成桩参数与水泥土桩身间的关系。试验结果表明:同步旋进注浆工艺能够在螺旋桩周围形成倒圆台状的水泥土桩身,水泥土桩身的平均黏结直径约为叶片直径的1.17~1.35倍;适当增加叶片数量能够使水泥与土体充分拌和,提高水泥土桩身的完整性与连续性,以改善HSCM桩的成桩质量;钻进速度大幅提高会导致注浆量不足,减小水泥土桩身的黏结直径与刚度;试验条件下HSCM桩的抗压极限承载力是螺旋桩的3.83~3.93倍,桩径扩大提高了侧摩阻力,注浆工艺加固并提高了土体强度,弥补了叶片在旋进过程中扰动土体造成强度降低的问题。 相似文献
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斜顶桩驳岸结构是一种深水高桩码头接岸结构型式,驳岸结构后进行高回填将是一个复杂的被动桩与土相互作用的问题。采用平面有限元方法,分别建立了后支撑和前支撑斜顶桩驳岸结构的桩一土相互作用模型,桩基采用梁单元模拟,桩一土界面采用接触对进行模拟,进行了高回填施工过程的仿真分析。将承台侧向位移的数值计算结果与原型观测值进行了比较,吻合较好,并对桩身侧向位移、板桩前后土压力以及位移场进行了分析。结果表明:结构的变形随着施工过程进行而变化,承台最大侧向位移发生在施工过程中;不同驳岸结构的被动土压力分布相似,而主动土压力由于支撑桩的位置不同而有所差别;后支撑桩的桩身挠度相对较大。研究结论可为此类结构的设计及计算提供参考,也可为深水港结构型式的优化提供建议。 相似文献
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The large-diameter cylinder structure, which is made of large successive bottomless cylinders placed on foundation bed or partly driven into soil, is a recently developed retaining structure in China. It can be used in port, coastal and off-shore works. The method for stability analysis of the large-diameter cylinder structure, especially for stability analysis of the embedded large-diameter cylinder structure, is an important issue. In this paper, an idea is presented that is, em-bedded large-diameter cylinder quays can be divided into two types, i.e. the gravity wall type and the cylinder pile wall type. A method for stability analysis of the large-diameter cylinder quay of the cylinder pile wall type is developed and a method for stability analysis of the large-diameter cylinder quay of the gravity wall type is also proposed. The effect of sig-nificant parameters on the stability of the large-diameter cylinder quay of the cylinder pile wall type is investigated through numerical calculation. 相似文献
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S. Moshfeghi 《Marine Georesources & Geotechnology》2019,37(1):67-80
Drilled displacement piles (DDPs) are known as an alternative to conventional foundations in coastal areas, given the elimination of environmental impacts and difficulties caused by installation process of driven piles and more consistency with environment. Despite increasing employment of these piles, the extent of research works does not yet suffice the requisites to reach a routine design. This paper aims to analyze six cone penetration test (CPT)-based methods of determining the bearing capacity of DDP. The statistical and reliability-based approaches were used in two parts of assessing performance of the methods with respect to soil–pile characteristics followed by evaluating reliability of the prediction outcome. A database is compiled including 65 DDP load tests with adjacent CPT profiles. Performance of the methods are analyzed. Finally, a reliability parameter, i.e., confidence interval, is introduced to demonstrate a more realistic insight into the evaluations by expressing performance of the methods in terms of a range for possible average values of the predictions ratios, rather than simply an arithmetic mean. The study reveals that the commonly used CPT-based methods which have not been specifically developed for DDP show great potential for design. The results indicate that the investigated methods can have promising performance if some modifications are applied. 相似文献
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Liqiang Sun Yandi Wang Shuwang Yan Jian Chu Xiaoqiang Liu 《Marine Georesources & Geotechnology》2018,36(6):709-721
The super-long and large-diameter steel pipe piles are often adopted for the construction of offshore oil platforms in deep sea. One constructability issue related to driving heavy pipe piles is the pile running. The term pile running refers to the quick penetration of a pile into the seabed as a result of its high self-weight and low resistance from the seabed. The unexpected pile running can cause the steel wire of the hammer to break or even the loss of the hammer. A case study of pile running at an oil platform is introduced in this paper. A simplified theoretical method is proposed to explain the mechanisms of the pile running in this case. A factor of friction degradation is proposed to calculate the dynamic skin friction from the static ultimate skin friction of surrounding soil. The comparisons between the predictions to the case history show that the proposed simplified method can be used to predict the pile running condition. 相似文献
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气象海况是组织海上油田生产的重要依据,通过查询海区历史气象资料,分析研究埕岛油田海域的气象规律和特点,紧密结合油田区城地理、海上施工及平台、船舶等设施及装备的基本情况,针对油田生产、海上施工等受气象水文因素制约、影响的不同特点,提出科学的组织生产措施,提高生产效率,保障安全生产。 相似文献
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大型涉水群桩桥基局部冲刷特性试验研究 总被引:2,自引:0,他引:2
利用正态宽水槽研究梅花形大型涉水群桩基础的局部冲刷特性,得到最大冲深、最深点位置以及桩群内垂向和顺水向的冲刷形态,并与常规形群桩布置引起的冲刷进行了试验对比.其中梅花形群桩局部冲刷的特性和试验结果在苏通长江大桥建设中得到较好地验证. 相似文献