Dynamic Characteristics and Simplified Numerical Methods of An All-Vertical-Piled Wharf in Offshore Deep Water

There has been a growing trend in the development of offshore deep-water ports in China. For such deep sea projects, all-vertical-piled wharves are suitable structures and generally located in open waters, greatly affected by wave action. Currently, no systematic studies or simplified numerical methods are available for deriving the dynamic characteristics and dynamic responses of all-vertical-piled wharves under wave cyclic loads. In this article, we compare the dynamic characteristics of an all-vertical-piled wharf with those of a traditional inshore high-piled wharf through numerical analysis; our research reveals that the vibration period of an all-vertical-piled wharf under cyclic loading is longer than that of an inshore high-piled wharf and is much closer to the period of the loading wave. Therefore, dynamic calculation and analysis should be conducted when designing and calculating the characteristics of an all-vertical-piled wharf. We establish a dynamic finite element model to examine the dynamic response of an all-vertical-piled wharf under wave cyclic loads and compare the results with those under wave equivalent static load; the comparison indicates that dynamic amplification of the structure is evident when the wave dynamic load effect is taken into account. Furthermore, a simplified dynamic numerical method for calculating the dynamic response of an all-vertical-piled wharf is established based on the P-Y curve. Compared with finite element analysis, the simplified method is more convenient to use and applicable to large structural deformation while considering the soil non-linearity. We confirmed that the simplified method has acceptable accuracy and can be used in engineering applications.

Application of Converted Displacement for Modal Parameter Identification of Offshore Wind Turbines with High-Pile Foundation

In the actual measurement of offshore wind turbines(OWTs),the measured accelerations usually contain a large amount of noise due to the complex and harsh marine environment,which is not conducive to the identification of structural modal parameters.For OWTs with remarkably low structural modal frequencies,displacements can effectively suppress the high-frequency vibration noise and amplify the low-frequency vibration of the structure.However,finding a reference point to measure structural displacements at sea is difficult.Therefore,only a few studies on the use of dynamic displacements to identify the modal parameters of OWTs with high-pile foundations are available.Hence,this paper develops a displacement conversion strategy to study the modal parameter identification of OWTs with high-pile foundations.The developed strategy can be divided into the following three parts:zero-order correction of measured acceleration,high-pass filtering by the Butterworth polynomial,and modal parameter identification using the calculated displacement.The superiority of the proposed strategy is verified by analyzing a numerical OWT with a high-pile foundation and the measured accelerations from an OWT with a high-pile foundation.The results show that for OWTs with high-pile foundations dominated by low frequencies,the developed strategy of converting accelerations into displacements and then performing modal parameter identification is advantageous to the identification of modal parameters,and the results have high accuracy.

A Method for the Damage Detection of Pile Foundation in High-Pile Wharf Based on A Curvature Mode Deletion Model

As the top of the pile foundation in high-pile wharf is connected to the superstructure and most of the pile bodies are located below the water surface, traditional damage detection methods are greatly limited in their application to pile foundation in service. In the present study, a new method for pile foundation damage detection is developed based on the curve shape of the curvature mode difference(CMD) before and after damage. In the method, the influence at each node on the overall CMD curve shape is analyzed through a data deletion model, statistical characteristic indexes are established to reflect the difference between damaged and undamaged units, and structural damage is accurately detected. The effectiveness and robustness of the method are verified by a finite element model(FEM) of high-pile wharf under different damage conditions and different intensities of Gaussian white noise. The applicability of the method is then experimentally validated by a physical model of high-pile wharf. Both the FEM and the experimental results show that the method is capable of detecting pile foundation damage in noisy curvature mode and has strong application potential.

The Research on Safety Evaluation of High-pile Wharf Structure

Due to a combination of the sea erosion,the ship collision,the change of ground condition,the effect of alternative static and dynamic load and the material deterioration,the structure of high-pile wharf is easily damaged.Once the structure of high-pile wharf destroyed,it is bound to be a great threat to the safety of various facilities and personnel in the port.Given all of that,the multi-level comprehensive evaluation method based on the extension theory is proposed in this paper.Using this method to assess the safety of high-pile wharf structure,the reasonable advice on its maintenance and reinforcement can be given in time.What’s more,the method is simple and can give more objective result of the evaluation.

离岸深水全直桩码头承载特性与简化计算方法

全直桩码头是一种新型高桩码头结构型式,在离岸深水海域得到越来越广泛的应用。该结构的承载机理、破坏模式及设计计算方法等与传统高桩码头结构存在较大差异,目前研究尚不完善。采用ABAQUS建立全直桩码头结构–地基相互作用三维弹塑性有限元模型,研究水平荷载作用下码头的承载变形特性及破坏模式。明确了对于水平荷载作用下的离岸深水全直桩码头,基桩的塑性破坏是结构失稳的控制因素,地基土体的承载力对结构水平极限承载力不起决定性作用。在此基础上,采用经典的P–y曲线,建立了全直桩码头水平向承载力简化计算方法。该方法可以计算出桩身任意位置的内力及变形,且适于大、小位移情况。并提出了以"塑性铰"作为简化计算方法中水平极限承载力的判断标准。通过与有限元计算结果进行对比,验证了所建立简化计算方法的正确性。

码头结构对波高分布的影响

结合广东省平海电厂码头工程建设,开展波浪整体物理模型试验,对工程码头、防波堤及护岸设计波要素,码头上水和港内波高分布进行了测定。分析了防波堤的掩护效果以及航道开挖对波浪传播的影响。根据工程不同码头结构及平面布置方案中的试验结果,分析不同码头结构对港域波高分布的影响,从而确定最优化的工程方案,为港口工程的设计、建设提供科学依据。

斜向规则波作用下离岸式高桩码头上部结构总上托力

旨在研究波浪入射角对离岸式高桩码头上部结构总上托力的影响,采用物理模型试验的方法进行研究。试验结果表明,随着波浪入射角的增大,总上托力逐渐减小,并且递减逐渐减缓。引进波浪入射角折减系数分析波浪入射角变化的影响,采用非线性数据拟合方法,取90%保准率,确定规则波作用下离岸式高桩码头上部结构总上托力随波浪入射角变化计算公式,计算结果和试验值吻合良好,可为设计提供科学依据。

长周期波涌浪裸岩海域钻孔桩施工技术

依托巴基斯坦胡布码头项目,对外海无掩护长周期波裸岩海域码头桩基施工进行研究。在船舶、顶升平台等传统设备无法满足施工条件的前提下,创新性地采用了工程桩支撑顶推平台减小波浪对施工的影响,采用前端“护筒振沉+旋挖跟进”的方式进行钢护筒的沉放,尾部采用旋挖钻成孔及灌注桩施工,提高了施工效率,解决了长周期波裸岩或浅覆盖层海域码头桩基施工的技术难题。

离岸深水全直桩码头结构群桩基础工作性状有限元分析

采用有限元法,建立了全直桩码头结构-地基相互作用的三维弹塑性有限元模型,研究了该结构群桩基础中各桩荷载分担比、桩身弯矩分布、桩侧土压力分布、群桩效应特性及桩基临界入土深度。结果表明:离岸深水全直桩码头结构群桩基础中群桩效应可忽略不计,这为研究该结构稳定性计算方法时可不考虑群桩效应。通过计算确定了该离岸深水全直桩码头结构水平承载群桩的临界入土深度。

离岸式高桩码头对后方护岸工程的影响

针对受离岸高桩码头掩护的后方护岸工程设计波浪难以确定的问题,结合实际工程,通过波浪断面物理模型和局部整体物理模型试验,研究码头工程对护岸设计波浪、越浪量和断面结构稳定性的影响。结果表明,高桩码头上部结构对后方护岸有良好的掩护效果,尤其在高水位时,消浪效果较好;受掩护良好的后方护岸工程,堤顶高程受高水位控制,可以适当降低堤顶高程;护岸结构稳定性,尤其护底、护脚块石,主要受较低水位控制,而低水位时码头对护岸的掩护效果有限,波高降低幅度很小。

钦州电厂码头及循环水取排水工程关键项目技术方案及实施

钦州电厂码头和取排水工程,结构复杂,影响因素众多。涉及墩式码头、海上灌注桩、近海沉井等施工,以及深基坑降水支护开挖、海上没顶箱涵安装等诸多项目。在几个关键项目施工准备和施工过程中,通过缜密深入的研究,结合现场条件提出了修改技术方案,并在实施过程中不断完善,取得了良好的经济和社会效益。文章就其中的几项关键项目技术方案和实施效果进行了介绍。

打桩船沉桩施工定位与碰撞预警实时监控系统开发与实现

针对复杂工况条件下海上打桩船施工定位与老旧码头改造、扩建过程中的海上打桩施工需求,研发了1套具有打桩船的精准导航、施工定位过程全要素实时三维立体化展示、桩身防碰撞预警以及竣工数据输出等功能的辅助定位系统。从需求分析、功能设计、核心算法、代码级实现方式以及实测应用方面对其进行阐述。该系统通过工前预控、辅助定位与竣工数据留存,精确评估施工安全性,可实现对整个海上打桩施工定位过程的全方位精准管控,满足施工人员的安全质量管控需求。

浅议外海深水码头建设的水动力问题

船舶大型化促进了我国建设外海深水码头的需求。外海深水码头的建设一般都因地制宜,有的建设于岛群之中,有的建设导堤将码头延伸于深水区,有的以建设人工岛为依托,有的建设墩式码头等。显然外海的水文条件大大地不同于海岸的水文条件,且条件更加恶劣,而人们对此认知甚少,资料缺乏,这给工程设计带来了许多困难。外海港口的建设会面临许多不同于海岸港口的问题和风险,需要预测、评估并提出对策,外海港口的运营也会带来一些新的问题,需要合理的解决方案。文中对建设过程中需要解决的有关水动力方面的关键技术进行了归纳总结。

离岸式高桩码头混凝土浇筑工艺

针对离岸码头混凝土浇筑水上施工存在施工难度大、受天气和海况影响大、施工进度及成本难以控制等难点,某30万吨级原油码头工程通过使用小型特制设备、混凝土地泵、混凝土泵车及多功能船等船机设备,实现一系列水陆结合的水上混凝土浇筑工艺的组合,并将部分混凝土浇筑由传统的水上船机作业转为陆上作业,提高施工效率,降低施工难度,节约施工成本,并保证了施工安全和工程质量。

吸力桶与圆沉箱整体预制式新型离岸深水码头

为了开发能够更好地适应软土地基和恶劣波浪条件的离岸深水码头,结合吸力桶和圆沉箱的优点,提出了吸力桶与圆沉箱整体预制式新型离岸深水码头。阐述其结构组成、平面布置和施工工艺,分析了其承载特性。该结构靠岸侧可布置泊位、靠海侧可兼做防波堤,抗浪能力强,具有承载性能好、结构刚度大、耐久性好、费用省和对环境影响小的优点,应用前景广泛。相比无隔舱的吸力桶,此新型结构通过设置内圆桶和内隔板,抗滑和抗倾覆能力大幅提高。贯入损伤对基础安装就位时的承载力有比较明显的降低作用,建议在设计中考虑。

超长组合桩在外海深水码头中的应用

乐清湾港区自然条件较差,设计水深大,码头使用荷载大,给码头桩基选型、设计、施工带来很大挑战。文章介绍码头桩基选型中考虑的因素、解决方案及实施效果,特别是超长大管桩组合桩的应用,对类似工程具有借鉴意义。

海上机场客运码头配置影响因素——以以中中国国香香港港、韩国仁川、日本关西国际机场为例

水上交通是海上机场相对于陆地机场特有的对外连接方式,海上机场是否设置客运码头,需考虑多方面因素。以中国香港国际机场、韩国仁川国际机场、日本关西国际机场3个典型的离岸式海上机场为例,分析海上机场配建客运码头的必要性。从案例机场对外交通现状出发,计算其陆路交通旅客输送能力,分析其水上交通在客运量方面的作用。通过对比案例机场陆路和水上交通旅客输送效率的差异,分析特定条件下水上客运交通具有的相对优势。从增强机场抵抗风险能力的角度,分析海上机场客运码头建设的必要性。在此基础上,讨论海上机场配置客运码头的主要决定因素。

海洋石油后勤支持码头物联网服务平台设计与应用

随着经济全球化以及现代供应链的快速发展,港口装备智能化成为第4代港口的发展趋势。中海油基地园区码头作为重要的海上平台物资保障码头,承担着绝大多数生产、生活物资和人员倒班出海的运行业务。供应链、物流服务、智能化、信息化等软实力建设可为油气后勤码头智能化运行、管理和后勤保障生产降低运营成本,进而提高运转效率,并整体提升码头安全管理水平。针对中海油后勤现代化港口的转型升级,对智慧化园区码头的物联网平台进行设计和应用,重点对物联网平台建设核心框架、平台框架搭建、数据采集预处理和平台基本功能进行了深入论述和总结。

海上风电出运码头工程总体设计

风电基地需实现陆域场地拼装、出运风机部件和码头前沿吊装风机整机这一整套复杂工艺流程,拼装工艺和码头平面的选择布置是工程设计的关键点。通过合理布置海上风电出运码头平面,选择适宜当地条件的拼装工艺,有效提升了拼装工效,为风电场的按期投运提供保障。

C海洋石油基地加水岸电工控系统设计要素与应用效果分析

C海洋石油基地码头是件杂货性质综合服务型码头,其最大特征是交叉作业,各类服务相互关联和彼此制约。提高海洋石油基地码头服务效能,需用系统观点将关键因素考虑周全,方案设计中注重场景需要和作业安全,实施应用中关注效率效果和耐久性安全性。通过将场景需求和信息技术一体化融合,达到真正解决现场问题,提升服务效率的目的。