后张法预应力预制梁混凝土施工工艺探讨

介绍了后张法预应力混凝土梁施工中的注意要点,针对后张法预应力梁混凝土不易振捣密实、箱梁芯模不易拆除等问题提出解决方法,从而保证后张法预应力预制梁的施工质量,进一步推广该技术的应用。     

后张法预应力混凝土T梁的施工技术

主要结合新胜高速公路后张法预应力混凝土T形梁的施工,介绍了后张法预应力混凝土T形梁的施工工艺、施工方法、主要施工设备,以及施工中可能出现的主要问题的处理措施和注意事项。     

后张预应力混凝土梁的预应力损失及控制

详细地分析了我国"规范"中后张法预应力混凝土梁预应力损失的成因、分项计算方法及控制损失的措施,为快速合理地进行预应力混凝土梁的设计提供依据。     

预应力混凝土梁孔道压浆质量控制

结合工程实际,介绍后张法预应力混凝土梁孔道压浆的浆体材料、配合比设计及灌浆施工工艺的控制,从而提高后张法预应力混凝土结构安全度和耐久性的措施。     

河南金版大厦工程有粘结后张法预应力施工

结合河南金版大厦工程后张法有粘结预应力混凝土梁结构施工,详细介绍了后张法有粘结预应力施工工艺,并具体阐述了预应力专项施工技术措施,以确保施工质量,积累了有粘结后张法预应力施工经验.     

预制后张法预应力混凝土铁路桥简支梁的预应力施工技术

预制后张法预应力混凝土铁路桥简支梁广泛应用于铁路桥的建设,其中在秦沈客运专线大成特大桥建设中采用了24 m、32 m 铁路后张梁;在大郑铁路增建二线、平齐线、沈吉线等既有铁路线改建的桥梁建设中,也广泛采用了铁路后张梁。在铁路后张梁的施工生产中,预应力施工技术是关键,重点介绍预应力施工方法。     

后张法在预应力T梁施工中的质量控制

随着现代桥梁施工技术的不断发展和提高．大跨度高预应力混凝土T梁得到越来越广泛的应用,后张法施工作为预应力T梁施工中的关键技术,对T梁的质量起着至关重要的作用。本文介绍了后张法预应力T梁施工中常见的质量问题,并提出了施工质量控制要点及预防措施,对指导类似工程施工具有很好的实用性。     

后张法在预应力T梁施工中的质量控制

随着现代桥梁施工技术的不断发展和提高．大跨度高预应力混凝土T梁得到越来越广泛的应用,后张法施工作为预应力T梁施工中的关键技术,对T梁的质量起着至关重要的作用。本文介绍了后张法预应力T梁施工中常见的质量问题,并提出了施工质量控制要点及预防措施,对指导类似工程施工具有很好的实用性。     

小议房屋建筑有粘结预应力施工工艺

文章结合工程实例,就后张法粘结预应力混凝土梁的施工工艺及要点和质量控制措施做了分析。     

预应力混凝土梁板施工中的质量控制

以安全、易操作的后张法为例,通过介绍预应力混凝土梁板的施工工序,着重阐述了预应力混凝土梁板施工的质量控制,为类似工程施工积累了丰富的经验。     

玻璃钢锚杆托盘及螺母极限应力和位移分析

为了研究支护用锚杆在极限应力作用下力学特性,建立了锚杆托盘及螺母的有限元模型,采用ANSYS程序对螺母及托盘的应力、位移进行了数值仿真分析。研究了托盘及螺母在极限应力下的接触特征;绘制了托盘及螺母的应力云图,得到了托盘及螺母内部的应力、位移分布情况。结果表明,托盘边缘及托盘内部大小圆盘连接位置较为危险;螺母中间位置由于受托盘的挤压容易发生破坏;加肋可以提高锚杆的极限承载力,为结构的优化提供借鉴。     

堆土加卸载与基坑开挖叠加对既有隧道变形的影响研究

针对堆土加卸载与基坑开挖叠加效应导致既有地铁隧道变形较大的问题,建立考虑加卸载叠加效应影响的三维空间分析模型,研究不同堆土加卸载叠加基坑开挖卸载模式对邻近地铁隧道变形规律的影响,探讨隧道在堆土加载、移土卸载再叠加基坑开挖下的变形规律。结果表明:正上方堆土加卸载对隧道的竖向位移影响较大,是侧向堆土加卸载的3倍～5倍; 在经历堆土加卸载后,隧道会残留不可忽视的变形,其残留竖向位移约为加载后位移的62%; 堆土加卸载叠加侧方基坑开挖时,隧道变形受基坑开挖深度的影响较大,大于隧道埋深的开挖阶段会加剧隧道变形; 4种叠加模式中,正上方堆土加卸载-侧方基坑开挖卸载隧道最终竖向位移最大,约17 mm,侧方堆土加卸载-异侧基坑开挖卸载隧道最终水平位移最大,约8 mm,邻近隧道施工时应充分考虑叠加效应的影响,尽量避免这两种情况。     

Magnetoelastische Spannkraftmessung in Bauwerken

Magnetoelastic Measurement of Prestressing Force in Civil Structures The knowledge of the tensile force of prestressing steel elements and its reliable and non‐destructive determination are of essential importance for the assessment of the structural health condition of prestressed concrete structures and tie‐back systems in terms of structural safety, serviceability and durability. For the evaluation of the prestressing force in steel tension members, the measurement technique presented in this contribution is using the magneto‐elastic effect (ME‐effect) of ferromagnetic materials. This effect describes the reverse‐proportional correlation between the mechanical stress and the magnetic properties of ferromagnetic materials. The cylindrical coiled sensors pushed over the tendon and the measuring device developed and practically optimized at the iBMB/MPA of the TU Braunschweig enable a fast and reliable measurement of the prestressing steel force after an initial calibration. In this contribution first the state of the art of prestress measurement techniques for steel tension members is presented. Afterwards, the ME‐measuring method with the basics and merits of magneto‐elastic prestressing force identification is shown. Further recent research results as well as several building applications will be discussed.     

Alternative Methods of Procurement for Works of Water and Environmental Management

The paper considers methods of procurement for the construction of water- and sewage-treatment works other than the traditional use of the ICE 5th Edition Conditions of Contract and Bills of Quantities. This is as a consequence of the speed at which schemes are currently required within the water industry.
The paper particularly focuses on the use of target contracts, using the Institution of Chemical Engineers'Green Book form, and considers various types of target. It also discusses the form which tender documents may take, and how targets may be calculated.
Tendering procedures, including the use of two-stage tenders and negotiated targets, are considered, as are the procedures for cost monitoring and the financial management of the contract. Finally, the role of the engineer and quantity surveyor is considered.     

基于点云的钢筋数量和间距自动检查算法

为改进钢筋骨架质量自动检查方法,提出了基于点云的钢筋骨架中钢筋数量和钢筋间距的自动检查算法。该算法在获取钢筋骨架实际点云和设计点云的基础上,首先对这两片点云分别进行降采样,以得到空间密集程度相同的钢筋骨架实际点云和设计点云; 其次,对降采样后的钢筋骨架实际点云和设计点云使用基于主成分分析(PCA)的方法进行粗配准。由于粗配准后的钢筋骨架实际点云和设计点云的配准精度较低,无法直接用于钢筋数量和钢筋间距的检查,对粗配准后的钢筋骨架实际点云和设计点云进行精配准。最后,基于精配准得到的钢筋骨架实际点云和设计点云,依次对钢筋骨架中的钢筋数量和钢筋间距进行检查。结果表明:精配准后的钢筋骨架实际点云和设计点云的配准精度较高,可以用于钢筋数量和钢筋间距的检查; 该算法对钢筋数量检查的准确率为100%,对钢筋间距检查的准确率为80%; 应用该算法可以有效提高复杂钢筋骨架中钢筋数量和钢筋间距检查的效率,降低人工成本。     

冻融环境中饱和岩石的热量传递与温度平衡规律

 冻融环境中温度是岩石性态变化的关键影响指标之一,而冻融试验中岩石的热量传递和温度变化规律国内和国际都未形成统一认识。为探究岩石在冻融环境中的热量传递和温度变化规律,利用室内试验和数值计算方法分别研究冻结和融化过程中试样温度平衡的过程和时程规律。利用3种岩石进行饱和态的冻融循环试验,试样中心温度监测表明,冻结和融化过程的试样温度均存在显著的3段式变化特征,其中相变过程是一个较为特殊和重要的阶段,相变温度均在0 ℃～－1 ℃范围。随着试验温度区间增大,冻结和融化各阶段时长显现出不同规律,冻结过程总时间逐渐降低,而融化过程总时间先降低后升高。基于第3类热传导边界条件,利用Comsol Multiphysics有限元数值计算平台,分析考虑相变阶段的冻结和融化过程,数值计算结果与试验结果吻合较好。数值计算结果显示,试样不同位置的冻结与融化特征主要体现在相变阶段差异,而试样孔隙率对该阶段的影响最大,剩余温度势造成对称温度区间和非对称温度区间的冻结、融化特征的显著差异。     

Application of sonic and radar tests on the piers and walls of the Cathedral of Noto

The authors applied systematically sonic tests, radar tests and other diagnostic techniques on the remaining walls and piers of the Cathedral of Noto. The experimental survey was carried out by the Laboratory of the DIS, Politecnico of Milan (Person in Charge: Prof. Binda, Prof. Baronio) in collaboration with the designers (Ing. R. De Benedictis, Arch. S. Tringali) and the experts working on the reconstruction. The Prefettura of Siracusa founded the research. The right aisle and most of the dome of the Cathedral collapsed in 1996. The aim of the research was to verify the state of damage and the possibility of conservation of the walls and piers in view of the reconstruction of the damaged part of the Cathedral. Furthermore, the sonic tests were used to control the effect of grout injection used as a possible technique for repair of the damaged masonry (Proceedings of the Conference on Nondestructive Evaluation of Civil Structures and Materials, Boulder, Colorado; (1992) 329; Proceedings of the Sixth Conference on Structural Faults and Repair, 3 (1995) 195). In the following the results will be reported and the reliability of the tests will be discussed as it was confirmed by the use of other complementary diagnosis techniques (Proceedings of the Sixth International Conference on Structural Studies, Repairs and Maintenance of Historical Buildings, STREMAH 99, Dresden, Germany, (1999) 323).     

露天矿山高陡岩质边坡生态修复技术的应用现状与发展趋势

矿产尤其是石材矿产的开发必然会对原矿区的环境造成破坏，容易形成矿山高陡岩边坡，即白茬山。白茬山由于坡度高、坡面长以及坡面温差大等原因，易形成恶劣的生存环境，很难实现有效的植被附着，长期复绿效果充满挑战。对此类生态环境中的常见复绿技术的研究现状进行了介绍，分析了不同技术的优缺点及使用机制。进一步根据白茬山的地质、地形和地表等特征，进行生态修复技术的优化与改进，展望修复技术的发展趋势，助力生态系统的恢复与发展。     

装配式建筑产业链多维度阐释及其供应链自主可控力影响因素测评

为增强装配式建筑产业链供应链自主可控力,保障装配式建筑产业链供应链安全稳定,采用文献梳理与实际调研结合法,贯穿全生命周期时空链,阐释装配式建筑产业企业链、供应链与价值链内涵及相互关系,进而构建装配式建筑产业链供应链自主可控力评价体系,采用COWA-DEMATEL法分析其自主可控力影响因素的综合中心度及其原因、结果效用,并从科技自主性、组织安全性与产业脆弱性3个方面提出了改善建议。结果表明:装配式建筑企业链属结构单元层面,价值链属结构目标层面,供应链属结构运行层面,三者存在相互作用、相互依存关系; 核心技术水平、外部环境波动、信息可控能力、合作协同程度、组织应急能力对装配式建筑产业链供应链自主可控力提升具有重要影响作用; 外部环境波动、资金自主水平、人员综合素质为影响装配式建筑产业链供应链自主可控力水平的主要原因因素,而产品安全水平为影响装配式建筑产业链供应链自主可控力水平的主要结果因素。     

The town and village greens of England and Wales

This paper considers the nature and significance of town and village greens within the landscape of England and Wales. It reflects on problems of definition and on the limited availability of data concerning the origins and geographical distribution of greens. The paper draws attention to the registration of greens following the Commons Registration Act 1965, and summarizes information collated from the registers subsequently prepared by local authorities. Details of numbers of greens and their spatial density at county level are presented, and reference is also made to rights of common on greens, and to the ownership of the greens themselves.