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.

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.

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.

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.

基于农业互联网平台的灌溉监测信息系统研究

为进一步提高我国农作物智能灌溉系统的作业效率,基于农业互联网平台,针对其灌溉监测信息处理环节展开研究。以大数据及SOA平台为核心架构,建立土壤环境参数与灌溉系统数据监测之间的内在关系,完成监测信息的布局设计与精准灌溉作业实现。进行系统在互联网平台下的灌溉试验验证,结果表明:基于农业互联网平台的灌溉监测信息系统改进后,各灌溉模块的功能运转效率得到显著提升,信息监测准确率与系统控制精准度分别提升至95.56%与94.51%,灌溉系统效率相对平台应用前提升了7.79%。所设计的联网平台架构下的灌溉系统整体改善效果明显,是我国向智慧农业方向迈进的重要基础,对于类似智能灌溉装备广泛推广有重要的参考价值。

浅析我国土壤污染团体标准发展现状及建议

土壤是人类社会生产活动的重要物质基础,是难以再生、不可缺少的自然资源。我国土壤污染问题比较严峻,为保护土壤资源和人类健康,采取有效的土壤污染防治措施至关重要。目前,根据全国标准信息公共服务平台和全国团体标准信息平台数据分析结果可知,我国发布有关土壤污染团体标准的社会团体数量共113个,发布团体标准数量为330项,仅低于地方标准数量。为了更好推动土壤污染相关团体标准的发展,本文结合团体标准发展现状和存在的问题,提出有关发展土壤污染领域团体标准的建议和对策。

区域弃渣综合利用信息管理平台研究与设计

随着城镇化进程加快,生产建设项目产生的弃渣日益增多。弃渣的全过程管理是水土保持工作的重点和难点,弃渣资源化利用也是环境保护与城市可持续发展的关键环节。本文构建区域弃渣综合利用信息管理平台,技术架构采用云原生技术、微服务架构以及容器化部署等方法,功能模块包括数据采集与智能分类、资源匹配与优化、环境监测与评估等,确保平台的高度扩展性和可靠性。通过实施该平台,促进弃渣的减量化、资源化,提升区域弃渣资源化利用效率和智能化管理水平。

深厚软土地区预留土台对基坑围护结构变形及稳定性影响分析

为研究深厚软土地区预留土台对基坑围护结构变形及稳定性影响,基于福州长乐滨海某具体深基坑工程,采用有限元分析方法对采取预留土台方式的基坑开挖进行模拟,分析有无预留土台以及不同土台尺寸等因素对基坑围护结构变形及稳定性的影响,并结合监测数据进行分析。研究结果表明:随着土台宽度的增加,围护桩水平变形随之减小,基坑整体稳定性随之增加;随着土台高度的增加,围护桩水平变形随之减小,基坑整体稳定性随之增加;当土台宽度较小/土台高度较小时,土台加固对围护桩水平变形控制效果明显,但当土台宽度较大/土台高度较大时,土台加固对围护桩水平变形控制效果有限。土台加固对基坑的整体稳定性均有提高作用。

新工科背景下管土作用创新实验教学平台设计

为推动深水复合柔性管道的设计和研究,依托重点科研项目成果,建立了管土作用创新实验教学平台。突出学生主体地位,通过文献调研、实验设计、实践操作和数值模拟,开展模块化实践教学,激发创新思维,塑造工程素养,促进对管土作用机理的探索与研究。创新实验教学平台的搭建,实现了理论实践、学科交叉及工程应用的有机结合,凸显了实验教学的工程性、实践性和探究性。

小型农田原状土样采集机器人系统研发与测试

农业机器人是农业机械领域的研究热点之一。国内外对温室/农田/果园作业(除草、施肥、喷药、采摘等)机器人移动平台的研究已取得初步成果,但对农田土样采集机器人移动平台的研究鲜有出现。在土壤的物理力学特性研究过程中,原状土壤样品的采集是一个重要前提。如果土样的原状度无法保障,后期实验室物理力学测试分析难以得出准确的研究结果。本研究针对这一问题,研发了一台结构紧凑、通过性强、取土质量好、取土效率高的农田土壤采集机器人移动平台,给出了机械系统、控制系统设计方案,并开展了初步的田间试验研究。本研究的主要内容如下:(1)机器人移动平台本体设计方面,确定了差速转向的转向方式;进行了机械系统设计,完成了相关硬件选型分析和控制系统设计以及软件编写。移动平台轴距为960 mm、轮距为600 mm,轮毂电机功率1000 W,实现了基于调速转把和遥控手柄的移动平台协调运动控制,满足试验要求。(2)土样采集装置方面,对分段原状取土装置进行了设计。通过对比分析选用液压传动作为动力源和直压旋入式入土方式。通过理论分析确定了取土器主要技术参数,并对其入土关键部件进行有限元分析,验证了其结构参数设计的合理性。(3)通过田间试验,考察整机的移动性能和取土质量。移动性能测试试验结果表明:最大垂直越障高度80 mm,最大爬坡坡度35°。土样抗剪强度检测试验结果表明:在获取0~200 mm深度土样时,环刀法和新系统所取土样的内摩擦角方差在0.05的置信水平下,P值等于0.866;在获取0~100 mm和100~200 mm深度土样时,环刀法和取土装置所取土样的凝聚力方差在0.05的置信水平下,P值分别为0.145和0.717。取土效率对比试验结果表明:该取土装置完成一次取土仅需3~5 min。

宁夏水土保持管理平台建设实践与探索

依据水利部和宁夏回族自治区水利厅信息化工作部署,宁夏回族自治区水土保持监测总站分批建成了集5个子系统19个模块的宁夏水土保持管理平台,供自治区、市、县三级水土保持管理部门和生产建设项目等相关单位、专家使用。平台在建设期、质保期、运维期稳定运行,全面支撑全区水土保持工作线上开展。分析了平台建设项目概况,总结了海量数据挖掘、关键因子智能化提取、资源整合共享、土壤侵蚀模型开发、智能化监管技术等平台建设的5方面问题,介绍了平台总体框架、技术路线和模块功能,归纳了数据底座建设、统一平台搭建、业务化转型推进和监管效能精准发挥4个方面的成效,以及坚持“问题导向”建设原则、“边建边用”推广应用模式、“建管结合”运维方式、“底线思维”保障安全4个方面的建设管理经验。

基于正交设计和重复试验的水泥混掺多灰混合土的改性试验研究

“双碳”背景下,为了研究水泥、石灰、粉煤灰和炕灰等胶凝材料对土和土坯预制块性能的影响,在通过正交设计和重复试验得出5种方案和基准配合比的基础上,验证了强度、自然损失和水损坏等性能指标。试验表明,细粒土在加入水泥、石灰、粉煤灰和炕灰之后,其强度能得到一定程度的改善。在胶凝材料总用量不变的条件下,随着水泥用量的减少、炕灰用量的增大,其强度先上升后降低,其质量损失率随着水泥用量减少而增大。得出结论如下:当水泥用量为10%,粉煤灰用量为5%,石灰用量为5%,炕灰用量为10%时,混合土的各项性能表现优异,28 d强度可达到1.5 MPa,自然损失率和水损失比均较小.

黏土中大直径钢圆筒在桩靴贯入时的稳定性研究

某在建水下生产系统附近有自升式平台的频繁桩靴插拔作业,采用了大直径薄壁钢圆筒作为水下生产系统的保护结构,因此钢圆筒在自升式平台桩靴插拔过程中的受力与变形备受关注。开展了离心模型试验,揭示了桩靴贯入过程导致的钢圆筒受力与变形规律;进而应用经离心试验验证的耦合欧拉与拉格朗日数值模拟方法,开展了筒-靴不同相对位置工况下,桩靴贯入对钢圆筒稳定性的影响分析。结果表明:桩靴贯入导致的筒壁附加应力及位移随筒-靴间距的增加而衰减,其衰减程度随筒靴间距的增加而减小,且由于筒靴间距的不同,钢圆筒对应存在两种受力模式。筒靴间距为2倍桩靴直径时,筒身附加应力可达110 MPa,表明桩靴对钢圆筒的影响距离可达2倍桩靴直径以上。

深圳市水土保持智慧监管平台研发及应用

智慧水土保持是智慧水利建设的重要组成部分,针对当前深圳市水土保持监管中信息化和智慧化程度不高的问题,围绕水土保持监管难题,在智慧水务总体框架的基础上,研发并利用水土保持专业模型、黄泥水溯源要素关系模型等关键技术,搭建包含生产建设项目监督管理、水土流失监测、水土保持生态建设、水土保持决策支持、水土保持信息服务、黄泥水防治等六大业务的深圳市水土保持智慧监管平台,实现水土保持业务全覆盖,为水土保持智慧监管提供技术支撑。结果表明:智慧监管平台有效提高深圳市水土保持监管业务中信息处理能力、应用智慧化程度,可为其他城市的智慧水土保持建设提供参考。

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.

泡沫轻质土在台背回填施工中的应用

介绍了泡沫轻质土的特点,如轻质性、独立性,自流性、施工便捷性、经济性、环保性,以及重度、强度可调节性,从施工准备和施工流程两个方面阐述了泡沫轻质土的施工工艺,并总结了其中的施工要点,有助于解决黄河冲积平原区路基施工难度大等问题,提高桥台台背、明涵台背回填施工的质量。

智能云平台搅拌桩监控系统及工程应用

施工与设计的符合性是搅拌桩施工的重点管控内容,智能监控是施工管控的主要方法之一。为了加强搅拌桩的施工过程监管,研发了适用于水泥搅拌桩的智能云平台监控系统,详细介绍了该系统的硬件和软件、基本工作原理及技术创新点。该系统硬件包括倾角仪、电流传感器、电磁流量计、深度传感器和新型密度计;软件包括可视化施工模块、智能化报警模块、专业化评分模块、电子化报表模块。通过硬件、软件和云平台的协同作用,可实现实时监控及预警功能,确保施工与设计的符合性。最后,结合实际工程的应用,验证了该系统可以实时监控施工桩长、水泥浆密度、水泥浆流量、电流、速度等施工参数,达到了加强施工过程监管的研发预期。

微扰动四轴搅拌桩数字化施工应用研究

针对水泥土搅拌桩施工过程中数字化程度低、桩体质量难控、施工数据无法回溯等问题,以微扰动四轴搅拌桩为依托,研发了数字化搅拌桩施工云平台,云平台由数字化施工控制系统、云服务器和交互平台组成,实现成桩过程数据的实时追踪与反馈。通过数字化施工云平台,施工前输入同地层匹配的成桩参数,实现了变参数的自动化施工;输入与钻头提升速度相匹配的钻杆转速,控制搅拌次数大于规范要求值;输入地内压力控制阈值,实现施工过程中对地基土的微扰动,实测土体侧向位移和地表隆起均控制在毫米级范围;通过钻头垂直度实时监测,桩体垂直度可达到1/250;通过管理云平台,实现参建各方对施工质量的动态管控。研究成果对于全面提升搅拌桩施工质量和软基施工数字化水平具有重要的实践意义。

通用型宽幅农机作业平台分析与设计

为提升传统农机作业装备的作业效率,减少土壤压实,提高作物产量及收益,可以采用宽幅作业平台作为通用行走装置匹配多种农机具作业。介绍了宽幅作业平台的研究开发背景,选取宽幅作业平台的行走模式、分布式四轮独立转向与驱动及模块化作业机具3个关键技术进行简要阐述分析,并对固定轨道作业平台、两轮驱动龙门式拖拉机和四轮/履带独立转向与驱动宽幅作业平台进行对比分析,提出通用型宽幅农机作业平台的初步设计方案,为国内宽幅农机作业平台研究提供参考。