Soil-Structure Interaction Analysis of Jack-up Platforms Subjected to Monochrome and Irregular Waves

As jack-up platforms have recently been used in deeper and harsher waters, there has been an increasing demand to understand their behaviour more accurately to develop more sophisticated analysis techniques. One of the areas of significant development has been the modelling of spudean performance, where the load-displacement behaviour of the foundation is required to be included in any numerical model of the structure. In this study, beam on nonlinear winkler foundation （BNWF） modeling--which is based on using nonlinear springs and dampers instead of a continuum soil media--is employed for this purpose. A regular monochrome design wave and an irregular wave representing a design sea state are applied to the platform as lateral loading. By using the BNWF model and assuming a granular soil under spudcans, properties such as soil nonlinear behaviour near the structure, contact phenomena at the interface of soil and spudcan （such as uplifting and rocking）, and geometrical nonlinear behaviour of the structure are studied. Results of this study show that inelastic behaviour of the soil causes an increase in the lateral displacement at the hull elevation and permanent unequal settlement in soil below the spudcans, which are increased by decreasing the friction angle of the sandy soil. In fact, spudeans and the underlying soil cause a relative fixity at the platform support, which changes the dynamic response of the structure compared with the case where the structure is assumed to have a fixed support or pinned support. For simulating this behaviour without explicit modelling of soil-structure interaction （SSI）, moment- rotation curves at the end of platform legs, which are dependent on foundation dimensions and soil characteristics, are obtained. These curves can be used in a simplified model of the platform for considering the relative fixity at the soil- foundation interface.

Dynamic Analysis of Tension Leg Platform for Offshore Wind Turbine Support as Fluid-Structure Interaction

Tension leg platform （TLP） for offshore wind turbine support is a new type structure in wind energy utilization. The strong-interaction method is used in analyzing the coupled model, and the dynamic characteristics of the TLP for offshore wind turbine support are recognized. As shown by the calculated results： for the lower modes, the shapes are water＇s vibration, and the vibration of water induces the structure＇s swing; the mode shapes of the structure are complex, and can largely change among different members; the mode shapes of the platform are related to the tower＇s. The frequencies of the structure do not change much after adjusting the length of the tension cables and the depth of the platform; the TLP has good adaptability for the water depths and the environment loads. The change of the size and parameters of TLP can improve the dynamic characteristics, which can reduce the vibration of the TLP caused by the loads. Through the vibration analysis, the natural vibration frequencies of TLP can be distinguished from the frequencies of condition loads, and thus the resonance vibration can be avoided, therefore the offshore wind turbine can work normally in the complex conditions.

Cyber-Physical-Social System Between a Humanoid Robot and a Virtual Human Through a Shared Platform for Adaptive Agent Ecology

Two artificial agents(a humanoid robot and a virtual human) are enriched with various similar intelligence,autonomy, functionalities and interaction modalities. The agents are integrated in the form of a cyber-physical-social system(CPSS) through a shared communication platform to create a social ecology. In the ecology, the agents collaborate(assist each other) to perform a real-world task(search for a hidden object)for the benefits of humans. A robot-virtual human bilateral trust model is derived and a real-time trust measurement method is developed. The role of taking initiative in the collaboration is switched between the agents following a finite state machine model triggered by bilateral trust, which results in a mixedinitiative collaboration. A scheme is developed to evaluate the performance of the agents in the ecology through the CPSS.The results show that the robot and the virtual human perform satisfactorily in the collaboration through the CPSS. The results thus prove the effectiveness of the real-world ecology between artificial agents of heterogeneous realities through a shared platform based on trust-triggered mixed-initiatives. The results can help develop adaptive social ecology comprising intelligent agents of heterogeneous realities to assist humans in various tasks through collaboration between the agents in the form of a CPSS.

Dynamic Finite Element Analysis for Interaction between Two Phase Saturated Soil Foundation and Platform

In this paper, the foundation soil of offshore structure is simulated as a two phase saturated porous medium. The dynamic equations of porous medium and finite element formulation are given. For structural analysis, the technique of multilevel substructure is used, and the saturated soil analysis is set in the highest level substructure model. Based on these theories a dynamic finite element analysis program DIASS for the analysis of interaction between two phase ocean soil foundation and platform structures has been developed. A numerical example is given here to illustrate the influence of the pore water in soil on the structural response of an ocean platform.

Optimum Design of Jacket Platforms Considering Structure-Pile-Soil Interaction

This paper proposes an optimum design model for the offshore jacket platform considering multidesign criteria, multi-design constraints and the structure-pile-soil interaction, and gives an optimum design procedure in which the proposed optimum design model is used together with structural analysis software SAP91 and optimum algorithm software OPB1. The Chengbei (#)11 offshore platform, which lies in the Shengli oilfield, is designed by use of the above optimum design model. The results show that the optimum design model is stable, and it depends on neither the optimization algorithm nor initial values of design variables. All values of the objective function converge to the same minimum value, and the speed of convergence is high, showing that the proposed optimum design model is reasonable.

Dynamic Response of Fluid-Single Leg Gravity Platform-Soil Interaction System

An approximate method is presented to investigate the earthquake response of the fluid-single leg (shortened for S. L.) gravity platform-soil interaction system. By assuming a suitable form of the velocity potential of the radiation waves and by using the motion equation and the boundary conditions, the unknown coefficients can be obtained. Thereafter the function of frequency for the interaction system may also be obtained. In this paper, the difference of the system dynamic response between rigid foundation is analyzed and the influences of the various foundation geometric dimension and the various water-depth on the hydrodynamic loading and dynamic response of the system is illustrated.

Analysis of Dynamic Interaction Between Deeply Embedded Platform and Foundation Soil

-Dynamic interaction characteristics of the model deeply embedded platform and foundation soil are studied by means of dynamic substructuring interface transformation synthesis and dynamic condensation. The theoretical analysis, computer programs and practical examples are presented; and the results are compared with those obtained by statical condensation method and finite element method.

DYNAMIC FINITE LAYER-ELEMENT ANALYSIS OF SOIL-STRUOTURE INTERACTION FOR NEW-TYPE OFFSHORE PLATFORM

In this paper, a new method called dynamic finite layer--element method (DFLEM) is used to analyse the soil--structure interaction of new type offshore platforms. Some valuable results have been obtained. The results show that the DFLEM is a new effective method to analyse dynamic soil--structure interaction and can be applied widely in practice.

Design and Realization of Meteorological Service and Meteorological Information Officer Management Business Platform Based on WebGIS Information Interaction

A meteorological service and meteorological information officer management business platform based on WebGIS information interaction is designed and realized.Firstly,the goals of system construction are introduced,and then the features of the system is analyzed.Finally,the subsystems of the system are studied,such as geographic information subsystem,information officer management subsystem,information release subsystem,information feedback and evaluation subsystem,radar analysis subsystem,time traceback subsystem,integrated display subsystem,etc.

Simulation of wave scattering over a floating platform in the ocean with a coupled CFD-IBM model

A numerical study of linear wave scattering over a floating platform has been simulated by an efficient numericalmodel in this letter.The non-hydrostatic model is used to simulate the free surface and the uneven bottom.For thesolid body modelling,the immersed boundary method(IBM)is implemented by introducing a virtual boundaryforce into the momentum equations to emulate the boundary conditions.This implementation enhances theability of the model to simulate interactions between waves and floating structures.A numerical case involvingwave interactions with a floating platform is studied to validate the numerical model.By simulating the wavepropagation,the numerical model captures the variation of the wave scattering very well,which verifies theperformance of the numerical model and the robust strategy of the IBM.

Design Method for Optimizing the Interactive Interface of Live Broadcasting Platform for the Elderly Users

In the era of network live broadcasting for everyone,the development of live broadcasting platforms is also more intelligent and diversified.However,in the face of a large group of elderly users,the interface interaction design mode used is still mainly based on the interaction mode for young groups,and is not designed for elderly users.Therefore,a design method for optimizing the interaction interface of live broadcasting platform for elderly users was proposed in this study.Firstly,the case study method and Delphi expert survey method were used to determine the design needs of elderly users and the design mode was analysed.Secondly,the orthogonal design principle was used to design a test sample of the interactive interface of live broadcasting platform applicable for the elderly users,and then a user evaluation system was established to calculate the weights of the design elements using hierarchical analysis,and then the predictive relationship between the design mode of the interactive interface of live broadcasting platform and the elderly users was established by Quantitative Theory I.Finally,Genetic Algorithm was applied to generate the optimized design scheme.The results showed that the design method based on the Genetic Algorithm and the combination of Quantitative Theory can scientifically and effectively optimize the design of the interactive interface of the live broadcasting platform for the elderly users,and improve the experience of the elderly users.

Online International Peer Interaction:An Exploration of Impacts on Comprehensive Competencies,Global Perspectives,and Cross-Cultural Communication Skills

With the increasing trend of globalization and the rapid advancement of information technology,online learning platforms such as Zoom are becoming increasingly influential in the field of education.The focus of this study was the online international peer interaction based on the Zoom platform,detailing how such interaction programs are conducted and exploring in depth the specific impacts of this interaction mode on students’comprehensive competencies,global perspectives,and cross-cultural communication skills.This research not only provides new practical references for online learning and international education but also offers new research perspectives and directions for educators and researchers.

平台型HRM、人力资源双元柔性能力与组织创新绩效:倒U型关系的独立与互动中介作用

以双元悖论观为理论基础,借鉴结构-行为-绩效(S-C-P)经典范式,构建平台型HRM-人力资源双元柔性能力-组织创新绩效理论分析框架,通过398个企业中高层管理者调研数据的实证分析,得出如下研究结论:平台型HRM倒U型影响组织创新绩效;人力资源双元柔性能力对创新绩效存在差异化影响,数量柔性负向影响创新绩效,功能柔性倒U型影响创新绩效;功能柔性在平台型HRM与组织创新绩效之间扮演独立中介作用,数量柔性与功能柔性的平衡效应(|数量柔性-功能柔性|)在平台型HRM和组织创新绩效之间扮演互动中介作用。

基于虚拟现实技术VR-Platform平台的产品展示研究

在互联网产品展示中,传统的虚拟现实产品展示过程产品与用户的交互性较差。因而,采用虚拟现实技术VR-Platform平台,设计基于虚拟现实技术VR-Platform平台的产品展示方法以提升用户的使用体验。使用3ds MAX软件构建产品的三维虚拟模型,对模型草图的关键点展开设定以保证模型构建的合理性。将构建完成的模型引入VR-Platform平台实现产品展示,为保证VR-Platform平台在产品展示过程具备高效运行效果,选定矩阵切换器优化展示设备构架。选定沉浸式交互为产品展示中的人机交互模式,通过相应计算对用户与平台的接触点进行人机交互模式控制。至此,基于虚拟现实技术VR-Platform平台的产品展示方法设计完成。通过构建交互性测试可知,此方法相较于原有方法的人机交互性能较好。由此可知,基于虚拟现实技术VR-Platform平台的产品展示方法的展示能力更佳。

基于VRP-Platform的唐山震前景观虚拟可视化仿真关键技术研究

结合虚拟现实和VRP-Platform平台,重点探讨了虚拟可视化技术在唐山市震前景观虚拟仿真中的应用,以及在与其它展示方式相比之下,所呈现出的独特优势,并且实现了从三维建模到导入VR-Platform平台中的整个流程,实现了虚拟交互展示。

Research on Interactive Teaching Strategies of College English Teaching-Based on Super Star Learning Platform

Super Star Learning Platform is a learning platform which meets the needs of interactive teaching mode both in and out of the classroom.This paper analyzes the advantages of interactive teaching strategies and the existing problems to be solved.Super Star Learning Platform can effectively improve teaching efficiency by enhancing the interaction between teachers and students and motivating students’interest in learning.

海陆交互相沉积软土中超深基坑支护设计与实践

海滨地区城市工程建设受软土工程特性影响,尤其在基坑工程中面临巨大挑战。以珠海地区海陆交互相沉积软土中某基坑工程为例,提出了“截水-降水-回灌协同控制”“非对称双翼栈桥”“非对称换撑传力框架柱”等基坑支护优化设计理念。根据基坑工程地质条件及施工部署,综合采用了卸土减载、SMW工法桩、排桩、钢筋混凝土内支撑等多种支护结构形式,并在地下水控制、土方挖运平台及非对称换撑等优化设计中进行合理的平面和空间结合,既保证了基坑支护结构及周边环境安全,又实现了土方快速挖运及地下结构的便捷施工,可为类似基坑工程的设计与施工提供参考。

Reliability-Based Design for Jacket Platform Under Extreme Loads

In this paper, reliability analysis for the offshore jacket platform with the interaction of structure- pile- soil under extreme environmental loads is carried out. The inherent uncertainties of the environmental load, foundation soil, platform itself, and calculating models are evaluated. The action of extreme loads on the offshore platform is modeled as a function of extreme wave height. The system capacity of the whole platform is determined by nonlinear pushover analysis, and the relevant probability property is obtained by the simulation method. The reliability model for the whole jacket platform is described as the relationship between the load and resistance based on the offshore design codes. The reliability of whole platform is calculated by the analytical method and the importance sampling method on the basis of a case study for a tripod jacket platform.

Hybrid Analysis Approach for Stochastic Response of Offshore Jacket Platforms

The dynamic response of offshore platforms is more serious in hostile sea environment than in shallow sea. In this paper, a hybrid solution combined with analytical and numerical method is proposed to compute the stochastic response of fixed offshore platforms to random waves, considering wave-structure interaction and non-linear drag force. The simulation program includes two steps: the first step is the eigenanalysis aspects associated the structure and the second step is response estimation based on spectral equations. The eigenanalysis could be done through conventional finite element method conveniently and its natural frequency and mode shapes obtained. In the second part of the process, the solution of the offshore structural response is obtained by iteration of a series of coupled spectral equations. Considering the third-order term in the drag force, the evaluation of the three-fold convolution should be demanded for nonlinear stochastic response analysis. To demonstrate this method, a numerical analysis is carried out for both linear and non-linear platform motions. The final response spectra have the typical two peaks in agreement with reality, indicating that the hybrid method is effective and can be applied to offshore engineering.

Design of A Bionic Spudcan and Analysis of Penetration and Extraction Performances for Jack-up Platform

The mechanisms of soil structure interaction have drawn much attention in the past years in the installation and operation of jack-up platform. A bionic spudcan produced by biomimetic of egg and snail shell is proposed, and the performance of the penetration and extraction are analyzed by numerical method. The geometric contour of egg and snail shell is measured, and its mathematical model is established respectively. According to the structure of existing spudcan of jack-up platform, three kinds of typical biomimetic spudcan are designed. Furthermore, numerical analysis models of biomimetic spudcan are established respectively to study the soil structure interaction mechanism in the process of penetration and extraction, and contrastive analysis of resistance characteristics are carried out. To conclude, the results show that the biomimetic spudcan facilitates the platform installation, and it is also beneficial to the improvement of the bearing capacity of spudcan.