【作者】 李振国；

【导师】 郭海燕；

【作者基本信息】 中国海洋大学 ， 港口海岸及近海工程， 2003， 硕士

【摘要】 大直径圆筒结构是一种新型的港口工程结构形式，其中插入式大直径圆筒具有结构简单、受力合理、材料用量省、施工速度快、适应地基能力强等特点，因而近十几年来在国内得到迅速发展应用。掌握大直径圆筒在沉入过程中的工作状态和力学机理，形成可靠的结构计算方法与施工实施方法，一直为学术界和工程界所关注。 本文针对以振动方式下沉的大直径圆筒进行动力分析研究，形成了以下成果： 在试验现场对大直径圆筒下沉过程进行了应力状态测试，以验证计算理论和方法的合理性，检验和完善振动下沉施工工艺，取得关键施工参数和积累经验数据。 结合试验观测结果，对计算模型和有关参数的选择进行了探讨，运用多自由度体系纵向强迫振动系统和土体等代流变模型，进行大直径圆筒振动下沉过程模拟计算，确定大直径圆筒在振动桩锤作用下的动力响应，给出了相应的计算公式。 利用计算结果确定筒壁的峰值应力，判断大直径圆筒的可沉入性以及振动锤系统的适宜性，反映大直径圆筒在下沉过程中的状态，解决与施工控制有关的问题。 通过实际观测资料与计算结果的对比表明，忽略偏位和倾斜等施工因素对变形和应力分布的影响、选取一维结构简化计算模型是可行的和合理的。本文提出的模拟分析方法可以较好地确定大直径圆筒振动下沉中的动力响应，可作为较简便的数值模拟方法。更多还原

【Abstract】 Large diameter cylinder structure is a new type of structure for portengineering, in which, the deep embedded one has many special characteristics,such as simple in structure, economical in materials, fast in construction suitablefor soft soil and so forth. That is why it has been widely applied at abroad inrecent ten years. Therefore, the problems to understand the mechanisms and workstatus of large diameter cylinder so as to form reliable design and constructionmethods have been keened on by the academic and engineering circles.The paper conducts research on the study of dynamic analysis for large diametercylinder driving by vibration.Observations and measurements of the cylinder’s stress were carried out duringthe driving operation in the site. The aim is to verify the reasonability of thecalculation theory and method, make clear construction processes and essentialparameters.Based on the multi-freedom system with vertical compulsory vibration and Kelvinmodel of soil. the paper carried out simulating calculation of large diametercylinder being driven to determine the dynamic response, and related formulawere given.The calculation results can be used to determine the stress of peak value, predictthe possibility of the large diameter cylinder to be driven, select the vibrator,indicate the working status of the large diameter cylinder and solve the relatedconstruction problems.The adaptability of the simplified model was verified with the site measurementresults. It shows that the dynamic analysis method is proper and adaptable.更多还原