Placing underground pressure pipes by machine

A machine system has been patented in the German Democratic Republic which links a digger and pipe placing unit for installing and connecting PVC pressure pipes underground with the minimum of soil displacement. The authors are engineers working at the Academy of Building, Institute for Civil Engineering, Leipzig.     

跨断层地下管道破坏的数值模拟

应用非线性有限元分析软件ADINA对跨断层地下管道破坏进行数值模拟,考虑管土相互作用,通过比较不同情况下管道的反应特征,发现跨断层地下管道破坏分析中管土摩擦不容忽视,并得出几点有益的结论.     

Modernization of underground pipes in towns in Poland

Renovation of the existing, worn-out network infrastructure in Polish towns is one of the basic elements necessary to make those towns conform to European standards. This problem has gained significance, especially in light of Poland's efforts to join the European Union. Rehabilitation of pipes is necessary as a result of the poor technical condition of pipes, their inefficiency, or the location of the pipes (e.g., in a location that interferes with planned development of underground space in towns). Trenchless technologies for renovation of underground network infrastructure are discussed, from technologies used for single pipes to multiconduit tunnels as a method for achieving complex modernization of infrastructure. Economic, technical, and legislative problems connected with the use of these solutions are also presented.     

地下燃气管网的有效识别

配置合理的地下燃气管网系统是满足城市居民(工商业用户)正常用气的先决条件,状况良好的地下燃气管网质量是用户安全用气的重要保证。而安全、正常供气有赖于科学、完善的管网规划、设计,有赖于全面、可靠的管网维护,有赖于燃气输配的合理调度,这就要求必须建立起地下燃气管网准确、详细的档案资料,并能够进行精确的检索,也就是说要对管网进行有效的识别。     

暗挖过街通道超前大管棚施工

以深圳红岭地下通道暗挖通道B管棚施工实例，介绍了大管棚的施工流程及工艺，并结合计算机三维技术解决了小半径曲线隧道管棚设计偏角问题。     

Model test assessment of the generation of underground cavities and ground cave-ins by damaged sewer pipes

Ground cave-ins caused by damaged sewer pipes have been frequently reported in metropolitan areas and have caused severe socioeconomic losses. In this study, model experiments were conducted to determine how damaged sewer pipes generate ground cave-ins or cavities, with a focus on the influence of the soil type and density. Digital images of the model ground were captured to evaluate the internal deformation of the model grounds. Additionally, the vertical displacement at the surface, the size of the cavity, and the weight of the discharged soil were measured in each test. The results indicate that uniform soil with no fines content was more vulnerable to ground cavities than well-graded soil with fines content. Loose soil led to a ground cave-in with significant deformation over the entire model ground, whereas deformation was concentrated only on the ground cavities in the dense soil ground.     

喷锚支护在市政沟槽跨越地下管线中的应用

介绍了成都三环路五段A标成黄路口市政深沟槽横穿已埋地下管线,采用窄槽边坡加固用喷锚网支护的设计与施工技术方法,通过沟槽边坡变形监测反馈于设计并指导施工获得了成功,为市政深沟槽跨越类似管线积累了丰富的设计与施工经验。     

PP-R管道自耦合压力密封伸缩节

针对塑料管材因热胀冷缩而引起的形变，研制了PP－R自耦合压力密封伸缩节，介绍伸缩节的结构设计、材料选择和优良性能。     

广州地铁施工盾构机整体转场实践

介绍了利用既有发电机定子吊装架,在国内首次实现盾构机整体出入井吊装、运输的思想和方法技术。     

地铁盾构的后续台车

用于掘进单洞单线地铁区间隧道的盾构，其直径一般都在6m多。盾构的后方拖着数节后续台车，台车上安放了动力、液压、操纵、控制等系统，通过牵引杆将盾构和后续台车连成一体。台车的数量主要根据需安放设备的大小和台数以及隧道内水平运输车队的长短而定，一般多在4～6节之间，少的只有3节，多的则达7～8节。单节台车的长度，多在6～8m之间，有做成等长的，也有不等长的，台车限界一般比隧道内壁小150mm。     

地下结构动土压力简化计算方法研究

基于波动力学理论,考虑土–结构动力相互作用、土介质特性及地震波的传播特性,提出了地震作用下地下结构的动土压力简化抗震设计方法。首先,将土–地下结构体系简化为单自由度的质量–弹簧–阻尼体系。其次,通过建立该体系的波动方程,并进行求解,将自由场响应换算为作用在结构上一点的动土压力,并结合结构周围土体的自由场响应分布特征,可得整个结构上的动土压力分布。最后,以振动台试验结果为基础进行了简化方法的验证,得出本文提出方法能够与试验结果吻合很好。该方法具有概念明确、计算简便、计算效率和精度高等特点,能够求解各类地下结构的地震反应,为地下结构的抗震设计提供了一种简单、实用的工具。     

蒸汽供热管道局部压力损失计算

对饱和蒸汽供热管道常用压力范围进行设定以简化蒸汽密度计算，给出了与沿程压力损失计算法配套的局部压力损失计算式，使压力损失计算法更加完整，可以更好地解决蒸汽供热管道水力计算问题。     

长春地区竖直埋管式地下换热井温度变化研究

针对竖直地埋管地源热泵系统运行特点,开发了地下换热井的测温系统.测量了地源热泵系统运行前换热井内的初始温度,推导出了适合长春地区的初始地温拟合方程.测量了地源热泵系统冬季供暖运行工况下地下换热井内的温度变化数据,总结出该地区冬季供暖时换热井内温度的变化规律.     

地铁区间隧道盾构始发掘进技术

以具体工程为例,简要说明在该工程地质条件下盾构的始发流程。从洞门密封、洞门破除、导轨安装、掘进方向的控制与调整等方面重点介绍土压平衡式盾构始发技术的组成及关键技术和施工工艺,并对盾构始发施工过程中出现的常见问题,给出建议性对策和预防措施。     

燃气管线周围密闭空间的潜在风险及预防

近年来发生了多起因燃气泄漏后积聚在密闭空间内引起爆炸的严重事故,对社会造成了恶劣影响。本文通过对几起事故的共性分析,提出消除或减少这种危害的几个措施与同行们交流。     

Placing Space

Abstract

With many architectural projects, there is little opportunity to study the construction of space from a movement point of view, while with many performance projects, there is little time to contemplate the influence of the physical environment on constructing experience. Placing Space: Architecture, Action, Dimension, a collaborative summer course at the University of Maryland offered to undergraduate and graduate students of spatial design and movement, provided an opportunity for dance and architecture students to mutually investigate the reciprocal role that movement and space can play on each other's formation.     

Placing Space

With many architectural projects, there is little opportunity to study the construction of space from a movement point of view, while with many performance projects, there is little time to contemplate the influence of the physical environment on constructing experience. Placing Space: Architecture, Action, Dimension , a collaborative summer course at the University of Maryland offered to undergraduate and graduate students of spatial design and movement, provided an opportunity for dance and architecture students to mutually investigate the reciprocal role that movement and space can play on each other's formation.     

智能式压力试验机课题研究

混凝土弹性模量是铁路梁场生产过程的重要控制指标,试验结果直接影响梁场生产进度与桥梁质量,而影响该项试验结果准确性的主要因素为试验设备智能化水平及操作过程信息化程度。通过本课题的研究,可提高弹模试验数据的准确性、及时性、完整性,减少弹模试验中试验人员数量,有效缩短弹模试验时间,实现弹性模量试验数据上传至工程管理平台,通过大数据对试验结果进行分析总结,为铁路领域梁体质量控制提供技术保障。     

Estimation of internal defect size by means of radial deformations in pipes subjected to internal pressure

Metals like carbon steel are used extensively in pipeline industries due to simplicity and economy. However, flaws such as cracks, pitting, local wall thinning can be generated by corrosion, erosion, and environmental exposure to various substances. In this paper, an analysis of asymmetric radial deformation in pipe with local wall thinning under internal pressure is proposed. The deformation is asymmetric with respect to the axis and consists of a radial displacement of all points in the wall of the pipe. Here, only the vertical and horizontal displacements in pipe are taken into account and they are calculated by means of strain energy method based on the classical Castigliano's theorem. In order to validate the results, a commercially available finite element code is used. The agreement between the theoretical predictions and numerical results is very close. It is found that the internal defect sizes can be estimated knowing the horizontal and vertical displacements.