Application Strategies of Pipe Jacking Technology in Municipal Rainwater Pipeline Engineering

Traditional construction techniques have a significant impact on the environment and are associated with long construction durations in the construction of municipal rainwater pipelines.Pipe jacking technology,a new type of pipeline construction method,enables non-excavation construction and can address the shortcomings of traditional pipeline construction.This article analyzes the concept and application advantages of pipe jacking technology.Combining engineering examples,it explores the application strategies of pipe jacking technology in the construction process of municipal rainwater pipelines for reference.

Application of ANSYS 3D FEM in Studies of Surface Deformation Caused by Pipe Jacking

By using site observation data and establishing 3D model using ANSYS software, this paper has discussed the strain change of stratum stress during process of jacking-in and the impact of machine head on ground surface under different frontal resistances. Analysis of the two cases shows that soil pressure reaches its maximum point when the soil is right above machine head, and soil stress will gradually decline when machine head passes over it. It also shows that impact brought by pipe-jacking construction on stress change of the surrounding soil is limited. The thesis suggest that road surface should be consolidated and soil condition be improved before construction to prevent loss and disaster caused by road surface deformation, jacking force can be increased so that jacking efficiency can be enhanced when ground stratum is well filled with soil, but the frontal resistance facing machine head should be equal to surrounding soil pressure in order to avoid rise of ground surface.

A study of jacking force for a curved pipejacking

For a pipejacking, the jacking force is critical to balance the resistance force and to move the pipe string forwards. The driving mechanism of a curved pipejacking is more complicated than a straight-line pipejacking, and its jacking force is also more difficult to be determined. The paper theoretically studies the jacking force of a curved pipejacking by considering the static equilibrium of earth pressure, resistance at cutting face, friction at pipe surface, and the driving force behind the pipe string. The derived theoretical formula can be used to estimate the driving forces of a straight-line or a curved pipejacking. Case study was performed by applying the theoretical and empirical formulae. After calibration, the corrected formula is more accurate and more applicable.

Behavior of Surrounding Soil during Construction and Its Countermeasures Using Pipe Jacking Method in Deep Strata

In Japan when urban infrastructures need to be constructed, the difficulty of utilizing the ground or shallow strata will lead to a more frequent use of the deep strata. The common construction methods are open-cut, pipe jacking, and shield methods. In recent years, a new pipe jacking method has been established that can be adapted to 20 m below the ground or more. Using this method, the drivage machine and the jacking pipe continue to move an underground until the completion of the driving. Therefore an over-cutting area (so-called tail-void) must be formed to lower the friction between the ground and the pipe. The tail-void is filled with lubrications. However, because the stress release from the ground continues to advance when the tail-void is formed, hence there are some challenges required to cope with the stability of the surrounding ground. In order to utilize the pipe jacking method in the deeper strata layers, the theory, analysis and installation of tail-void have to be systemized, and such systematic data must be stored. Therefore, the conditions of tail-void in the deep pipe jacking method are discussed using numerical analyses.

Effect of Application of Pipe Roof Method by Using Pipe Jacking on Behavior of Surrounding Soil

Tunnels in an urban area, in many cases, are constructed in soft ground which contains underground water, near existing facilities and structures. Structural stability for the tunnel and also the nearby structures and facilities is vital in this kind of work. Slurry pipe jacking was firmly established as a special method for the non-disruptive construction of underground pipelines of sewage systems. This method utilizes mud slurry that is formed around the pipes in order to stabilize the surrounding soil. In the pipe roof method the tubing elements that are constructed by slurry pipe jacking are near each other longitudinally, and create a rigid and stable lining before the excavation of the main tunnel. This paper discusses ＇the application of a slurry pipe jacking system on ＇the pipe roof method by means of numerical analysis. Because of the rigid behavior of the lining, the results show little subsidence, making this method a reliable method of constructing large tunnels with small cover in an urban area.

Long-Distance Pipe Jacking in Complex Urban Geological Environment

A steel underground pipeline with a diameter of 2.4 m and a total length of 3,617 m(plate thickness of 26 mm)has been constructed in a city in central Hubei,and the engineering,procurement,and construction(EPC)project has been lifted from the upstream channel to supplement water to the downstream lake inside the city.Through preliminary geological survey data,site topographic and geomorphic survey,urban construction,as well as the requirements of the construction party,the preliminary arrangement of working wells and receiving wells as well as the selection and customization of pipe jacking machines have been proposed.Frequency conversion motor and remote monitoring technology are adopted for geotechnical change and long-distance pipe jacking.Through detailed survey,the rock and soil change section as well as gradual change conditions have been determined,the accuracy of construction mechanics calculation and construction operation control have improved,the basis and analysis basis are provided,and some experiences in construction operation are summarized.

Numerical simulation of frost jacking response of a single pile considering hydro-thermo-mechanical coupling

Permafrost is widely distributed in China and around the world.In permafrost regions,soil frost heave and thawing are severe and frequent,and can destabilize pile foundations.To this end,a finite element model of a single pile in frozen soil is established to investigate the frost heave and frost jacking response to ensure its safety in the Qinghai-Tibet Plateau.Firstly,a hydro-thermal coupling model of a single pile in frozen soil is established based on coupling parameters and initial and boundary conditions.Then the temperature and moisture distributions are analyzed through the established coupling model.A hydro-thermo-mechanical coupling model is developed by importing the ice content and temperature results.Simulation results indicate that the amount of frost heave is greater at locations closer to the ground surface,and the displacement is smaller for frozen soil that is closer to the side of the pile.The results on frost jacking behavior of piles from this study can serve as a reference for the design,construction and maintenance of foundations.

Finite Element Analysis Study of Box Culvert Jacking-Out Construction under Existing Railway Line

To shorten the existing box culvert demolition construction period and ensure the normal operation of the railway, the jacking-out construction method was adopted. The ABAQUS finite element software was used to establish a three-dimensional model of the box culvert and soil body of the relying project, and three excavation thickness (0m, 1 m, 2 m) were used as the main variation parameters for numerical analysis and research, and the change law of the box culvert itself and soil body stress during the culvert jacking out process was obtained. The results show that the jacking force-displacement curves of the three working conditions can be divided into two stages, and the jacking force reaches the maximum value at the moment when the static friction turns into sliding friction at the end of the first stage. The stress distribution at the bottom slab of the box culvert in the jacking process is approximately normal, and the stress decreases with the increase of the roadbed excavation thickness. The increase of the roadbed excavation thickness can reduce the soil pressure on the side of the box culvert and effectively reduce the deformation of the roadbed in the jacking-out process. The deformation of the roadbed during the jacking process can be reduced by increasing the thickness of the roadbed excavation.

Discussion on the Application of Pipe Jacking Construction Technology in Municipal Road Drainage Projects

In the construction of municipal road drainage projects,pipe jacking construction is a relatively common construction method.This construction technology can avoid a large amount of excavation work,improve drainage construction efficiency,avoid large-scale damage to the road surface,and exert small traffic impact.Therefore,it is currently widely used in drainage construction,but judging from the current actual application situation,there are still many problems that require further improvement.This article mainly analyzes the advantages of and current technical problems in pipe jacking construction technology in detail,explores corresponding solutions,and lays a foundation for the optimization of municipal road drainage engineering construction.

飞机牵引车驾驶台人机工程仿真分析及设计改进

为提升飞机牵引车驾驶安全性和舒适性,根据其操作流程提取驾驶员关键操作姿势并进行人机工程分析。在Jack软件中导入飞机牵引车驾驶台数字模型,并根据GB∕T 10000—1988建立的成年男性人体数字模型,搭建驾驶员驾驶、换挡、操作中控屏、一键启动及紧急停止5个关键操作姿势;采用Jack软件对关键操作姿势进行驾驶员可视域、可达域及舒适度的仿真分析。结果表明:驾驶姿势下,驾驶台右部区域相较于前部区域的可达程度更高,且驾驶员在一键启动和紧急停止两种操作姿势下的舒适度较差。基于分析结果,将驾驶台的一键启动和紧急停止按钮布置到驾驶台右侧区域。对设计改进方案分析后发现:驾驶员一键启动与紧急停止2种关键操作姿势的Porter和Krist舒适度参数趋向舒适。采用虚拟人机工程仿真技术,对驾驶员的关键操作姿势进行人机合理性分析,可为复杂装备产品设计的方案迭代提供有效依据。

基于JACK虚拟仿真的学龄前脑瘫儿童助行器人机优化设计

目的减少学龄前脑瘫儿童助行器的安全隐患,解决患儿在训练过程中的肢体二次损伤问题,提升助行器人机舒适性,对学龄前脑瘫儿童助行器进行优化设计。方法通过JACK虚拟仿真软件的RULA工具,分析得到学龄前脑瘫儿童在使用助行器过程中存在的不合理姿势,并对其进行人机工学与受力分析,提出改进方法并进行设计优化,最后导入JACK虚拟仿真软件进行风险与舒适性验证。结果优化后的学龄前脑瘫儿童助行器的使用受伤风险从4级降低到1级,患儿躯干弯曲力矩、L4/L5脊柱压缩力、剪切力的姿势载荷指数分别降低53%、47%、81%,上身各关节处于舒适角度。结论经过JACK仿真分析及人机优化后的助行器,有效降低了学龄前脑瘫儿童在康复训练中的二次损伤风险,减轻了患儿步行训练中的身体负担,提升了助行器使用的舒适性。

消防员负重训练姿势仿真分析

目的 研究消防员负重状态下不同训练姿势的损伤风险和疲劳状况,降低其身体损伤和职业病的发生。方法 采用调查问卷对某消防救援大队消防员的训练损伤情况进行详细调查;针对引起损伤原因中占比最高的运动疲劳因素,使用Jack软件中的下背部分析、静态强度分析、疲劳度分析、舒适度分析等人因分析工具,对消防员的4种常用射水训练姿势,以及5层楼负重跑、挂钩梯攀爬科目的训练姿势进行仿真分析。结果 调查问卷统计显示,该消防大队消防员损伤的最主要因素是运动疲劳,其引起的损伤占比为69.8%。4种射水姿势均会造成膝、踝关节受伤的风险增加,4种射水姿势的舒适度从高到低依次为肩扛式、站立式、单膝跪地式、卧倒式。对于5层楼负重跑和挂钩梯攀爬的整个动态训练过程,消防员下背部均不会有增加的损伤风险,但踝、膝关节均有增加的损伤风险。结论 消防员负重训练存在某些训练姿势和部位不适、损伤风险增加等现象。研究结果为预防和降低消防员训练损伤、制定合理的训练计划以及有针对性的防护措施,提供科学的参考依据。

观光电梯装饰设计方案评价体系建构

通过研究观光电梯装饰设计中的人机工程学与CMF问题,重构了观光电梯装饰设计评价体系。首先,通过Jack软件模拟电梯中的人机交互情景,分析设计方案在可达域、视域、舒适度和工作姿势等方面的表现;其次,利用层次分析法明确评价体系各指标之间关联性和重要性,采用几何平均法计算指标权重;最后,依据评价体系开展设计案例全面评估,根据评分结果得出结论,并提出优化建议。提供一种综合而全面的评价方法,提升了设计评价准确性,对观光电梯装饰设计具有指导意义,也为电梯设计方案的优化提供了可行性建议。

基于Jack的挖掘装载机驾驶室人机工程分析与改进设计

为提高挖掘装载机驾驶室的舒适性,采用人体模型建模分析法确定H点位置,并建立挖掘装载机驾驶室人机仿真系统。以人机分析软件Jack为工具,从驾驶员可视性、可达性及舒适性3方面进行挖掘装载机多作业姿势的人机合理性分析,根据仿真结果对中控台界面及控制部件布局进行改进设计,改进方案的分析校核结果表明:驾驶员可视域得到提升,常用控制部件位于驾驶员舒适可达范围内,改进后驾驶员的多个作业姿势舒适性得到提升。通过人机仿真软件对驾驶员多作业姿势进行人机合理性分析,较准确地发现了挖掘装载机驾驶室存在的设计缺陷,为具有复杂人机系统的工程装备驾驶室布局设计研究提供一定参考。

普速列车硬卧车厢新型布局设计

为提升普速列车硬卧车厢乘客舒适性及安全性,根据乘客坐姿、高处行李放置及上下爬梯3种姿势的人机场景,以及人机工程软件Jack的仿真分析结果,发现现有25G型硬卧车厢存在无法满足中、上铺乘客坐姿休息、行李架与爬梯易用性和安全性较差等问题;结合TRIZ理论中物理冲突、技术冲突及物质-场模型的对应解工具确定设计改进方案,对改进方案进行人机合理性及仿真分析校核。改进后,中铺和上铺乘客起坐空间高度增大,高处行李放置区域高度减小,可满足不同百分位乘客中、上铺坐姿及个人行李放置需求;乘客上下爬梯的踏板视野盲区及RULA舒适度评分等级减小,爬梯过程中的铺位扶手可达性及上肢舒适性得到提升。

骑行下肢外骨骼结构与造型舒适度设计研究

针对下肢外骨骼结构功能固化和造型主观舒适度难以满足人机要求等问题,本文基于骑行姿势提出了一种结构与造型相结合的外骨骼设计方法和舒适度验证方案。基于骑行中的运动学和仿生人机分析,提取出外骨骼需要满足的结构因素。再通过感性工学和设计美学在结构基础上进行造型因素分析和方案设计。基于JACK,从外骨骼的穿戴和交互舒适度出发,对人体下背部人机匹配性等进行结构功能舒适度验证。并对外骨骼方案进行主观舒适度验证。基于骑行姿势结构与造型相结合的外骨骼设计方法。可以设计出既满足结构功能,又满足造型主观舒适度要求的迭代性外骨骼方案,为下肢外骨骼设计与研究提供指导作用和积极意义。

基于Jack的老年电动代步车人机工程设计与优化

目的满足行动不便的老年用户群体复杂的出行需求,提高电动代步车类工具使用过程中的舒适度。方法在传统老年电动代步车的基础上附加辅助站立结构,创新设计出一款坐、立两用的新型电动代步车,并借助Jack仿真软件,对老年用户坐姿驾驶和辅助站立支撑状态下的舒适度、可达域、可视域,以及上车过程中L4/L5下背部的受力情况进行分析,以验证关键人机交互结构、尺寸设计的合理性及舒适性。结论通过验证和调整,对电动代步车的初期设计方案进行改进,优化后的方案为老年电动代步工具的设计提供了参考,可以为满足老年用户复杂的出行需求、提高电动代步车类工具使用过程中的舒适度和安全性提供帮助。

基于JACK的不同身高笔记本电脑使用者的脊椎受力状态研究

目的在探讨笔记本电脑放置位置对使用者胸椎、腰椎受力和头部屈曲的影响。方法通过Jack软件构建了P 1、P 5、P 50、P 95和P 99的数字人仿真办公模型,分析了屏幕在不同垂直距离和水平距离下人体spinetT1/T2、spineL4/L5受到的力矩和Head Flexion的角度,使用SPSS对获得的数据进行相关性分析。结果在坐姿使用笔记本电脑时,用户的身高越高,其胸椎和腰椎所承受的力矩也越大。笔记本电脑屏幕的高度对使用者的影响显著高于水平距离的影响。结论通过调整笔记本电脑的放置位置,特别是屏幕的高度,可以有效降低不同身高群体颈部和腰部的疲劳和疼痛症状,减少对身体的损伤。

基于人因学及Jack仿真的消防操作台设计

从人因学的角度出发,根据消防救援任务对车载单人消防机器人操作控制平台进行设计,并依托计算机辅助布局方法和双手作业分析,借助yaahp软件等进行操控器位置协助和布局,针对设计后的人机界面进行了Jack仿真分析,通过人因学多项反应时间实验及按键双手协调实验对设计效果进行分析评价,以减少长期作业带来的疲劳,有效提高作业人员操作的精准性。

基于情境分析和DEMATEL的老年人家居轮椅设计研究

目的提高下肢障碍老年人在家居环境下使用轮椅的舒适度和自主参与性,从而满足老年人多层次生理和心理需求。方法以情境分析和DEMATEL集成方法辅助创新设计决策为主,人机状态舒适度评价为辅。利用情境分析法对老年人、轮椅、家居环境情境要素和三者之间的交互关系进行分析确定情境冲突,建立设计规约,从而获取老年人轮椅期望需求指标;结合DEMATEL分析方法,识别和分析各需求要素之间的相互影响关系和在系统中的重要程度,从而指导设计实践;最后利用JACK仿真软件对设计方案进行人机舒适性分析验证。结论通过情境分析和DEMATEL集成方法展开的老年人轮椅设计实践,设计方案通过了JACK虚拟仿真的人机舒适度验证,符合设计预期,为相关适老化轮椅产品设计提供一定的参考思路。