Experimental and finite element study of profiled steel sheet dry board folded plate structures

Folded plate structures constructed with profiled steel sheeting connected to dry boards by self drilling, self tapping screws (known as the PSSDB system) are being proposed as an alternative to traditional forms of roof construction. This paper describes the analysis, testing, and the structural behaviour of such kind of structures. The proposed efficient and load bearing structural system consists of an assembly of individual PSSDB panels connected by steel angle plates at the ridges, formed to the required shape, width and span. An analytical model using finite element method has been proposed. The profiled steel sheeting was idealised as an equivalent homogeneous orthotropic thin shell plate elements of constant thickness. Two directional plate elements were proposed in modelling the connection between profiled steel sheeting and dry board to include biaxial shear deformation. The proposed analytical method has been used to analyse the results of full-scale folded plate PSSDB tests and is found to give good results.     

高架桥组合箱梁挑架及模板的设计与施工

结合北京南站改扩建工程,介绍了高架桥组合箱梁挑架及模板的设计与施工,提出了桥面混凝土板翼缘部分采用三角挑架及铝木模板体系的施工方案,从而解决了该工程与桥面同时施工的进出站通道和站台等处无法搭设脚手架的难点问题.     

Flexural behavior of an alternative lath mortar deck plate

In the domestic construction industry field nowadays, the usage of deck plates is currently increasing due to the lack of construction workers and the rised in construction cost. However, using deck plates manufactured by thin zinc galvanization in underground structures is criticized because it can lead to increase in maintenance cost caused by rust generation and water leakage. As a solution for this particular problem, deck plates created by Lath and Mortar instead of zinc galvanized steel sheets were developed. This paper deals with the experimental study on flexural behavior of deck plate using metal lath and mortar. Seventeen full scale specimens were constructed and tested with different type of truss, the diameter of the top and bottom bar, and the thickness of slab. Tests results show that LAMO deck displayed equal performance such as zinc galvanized steel sheets.     

新型轻钢复合墙体承重抗火试验及其墙柱热翼缘温升简化计算研究

提出以蒸压加气混凝土(ALC)板与玻特(CS)板作为覆板组合、以钢蒙皮和钢带作为墙板拼缝保护措施的新型轻钢复合墙体构造,开展了ALC板-CS板覆面的新型构造轻钢复合墙体足尺模型承重抗火试验。将轻钢复合墙体受火侧由不同覆板组合而成的防火构造简化为一层均质防护层,提出均质防护层的等效热物理参数(包括厚度、比热容、密度和导热系数)简化计算方法。根据能量守恒原理以及有限差分方法,提出ALC板-CS板覆面轻钢复合墙体的墙柱热翼缘受火温升简化增量表达式。结果表明:ALC板-CS板覆面轻钢复合墙体在0.27荷载比率条件下发生高温承载力失效的耐火极限达到197 min,表现出优异的耐火性能; 提出的温升简化增量表达式预测结果与有限元模拟结果吻合良好,可以用于确定轻钢复合墙体的耐火极限。     

钢丝网架聚苯乙烯板外墙外保温施工技术应用

结合具体的工程实践,从钢丝网架聚苯乙烯板的安装到其表面装饰,介绍了钢丝网架聚苯乙烯板的施工技术,详细阐述了该保温施工技术的构造措施和要求,从而有效预防钢丝网架聚苯乙烯板表面抹灰裂缝的产生。     

Inelastic behavior of orthotropic steel deck stiffened by U-shaped stiffeners

Owing to its high strength and stiffness, the orthotropic steel deck system has been widely used in the construction of long-span steel bridges. However, due to esthetic and economic considerations, slender types of orthotropic bridge have become very popular in recent years. Consequently, the stability of the orthotropic steel deck system under traffic load becomes more critical. Although the instability problem of the orthotropic steel deck system due to flexural compressive stress has been recognized for years, current bridge design specifications do not clearly specify the criteria to prevent local buckling of the orthotropic deck system. Most previous studies on orthotropic steel deck systems were focused on the out-of-plane behavior of the steel deck, and limited study has been carried out on the in-plane compressive behavior of the orthotropic steel deck system. There is a lack of knowledge on the inelastic behavior of the orthotropic steel deck system under flexural compressive stress. In this study, the inelastic behavior of 30 full-scale orthotropic steel deck specimens was examined. According to this study, it is found that the current design practice may lead to local buckling of the deck system. Based on this study, criteria are proposed for the requirement of compact and non-compact sections. Design guidelines for the inelastic ultimate strength of the steel deck system are also suggested.     

钢-超高性能混凝土组合板冲切性能试验研究和承载力计算

钢-超高性能混凝土(UHPC)组合板是将钢板与UHPC通过连接件组合成整体,具有高强、高延性、抗开裂、施工便利等特性,可应用于桥面板、防护工程等结构中.由于钢-UHPC组合板相对较薄且往往承受集中荷载,因此需要对其抗冲切性能进行重点研究.通过变化连接件参数、UHPC厚度、钢板厚度和加载区边长,完成了14块板件在集中荷载...     

悬挑脚手架对建筑结构的影响分析

本文分析了某高层住宅屋面局部悬挑钢构架施工过程中,悬挑脚手架的搭设对建筑结构构件内力的影响。分析结果表明,悬挑脚手架的搭设改变了荷载传递路径,导致某些构件在施工过程中内力较大。悬挑脚手架对建筑结构的影响应给予重视。     

Fire Performance Properties of Solid Wood and Lignocellulose-Plastic Composite Deck Boards

Traditionally fire performance properties of externally located deck boards have been characterized by their flame spread index (FSI) as determined by UL 723/ASTM E 84. In this test a nominal 0.6 m wide by 7.3 m long array of deck boards is exposed to an approximately 90 kW ignition source fire for 10 min in the Steiner Tunnel. More recently the University of California Forest Products Laboratory developed a new fire test protocol based the principles of oxygen consumption calorimetry, California SFM 12-7A-4, Part A: Under-Deck Flame Test. This protocol addresses the potential ignition of a deck from underneath as may occur during a wildfire. In this protocol a nominal 0.44 square meter deck-system of deck boards mechanically fastened to wood joists is subjected to an 80 kW ignition source fire for 3 min. For this study the fire performance characteristics of more than thirty-five deck board types were evaluated by the above two methods and by a smaller-scale material-based test, ASTM E 1354 cone calorimeter. Deck boards were selected to represent a range of materials (untreated wood, lignocellulose-polymer composite), structures (solid, voided, microcellular foam), and cross-sectional profiles (width, thickness, presence of hidden fastener system longitudinal edge grooves). The results from this study were used to: 1. Develop correlations for deck boards between the material-based cone calorimeter tests and system-based under-deck tests. 2. Develop correlations for deck boards between the small-scale cone calorimeter tests and large-scale Steiner Tunnel tests. 3. Estimate the significance of ASTM D 2898 Method A accelerated weathering on fire performance.     

Experimental investigation of deck plate system with non-welding truss type deformed steel wires (tox deck plate slab)

On the bases of a decreased construction period and convenience of construction, the steel deck plate system has been widely used in the construction field in Korea. In particular, due to its good stiffness and economic considerations, the steel-wire-integrated deck plate system (or truss deck plate system) has become very popular in recent years. But while it offers many advantages, the truss deck plate system has a critical defect: rust forms in the welding joints between the lattice steel wire and the deck plate, resulting in the cracking of these welding joints and water leakage. To address these problems, the TOX deck plate system, a new type of truss deck plate system that does not require welding and does not rust, is proposed in this paper. Tests have been conducted on 15 specimens to evaluate the structural safety of the proposed deck plate system during the construction stage. The test parameters were as follows: the depth of the slab, the length of the span, the diameters of the top, bottom, and lattice steel wire, and the material properties of the zinc-coated steel sheets. The test results show that the TOX deck plate system can guarantee structural safety owing to its deflection and strength.     

钢结构屋面隔汽、保温与防水一体化施工

介绍了某公司钢结构屋面隔汽、保温、防水一体化工程的设计与施工技术,其屋面构造自下而上依次为钢板、自粘卷材、岩棉板、SBS改性沥青防水卷材、带岩片SBS改性沥青防水卷材。文中较详尽地介绍了此屋面工程的选材及施工工艺。     

高墩带脚手钢模板整体提升新工艺

本文提出大型带脚手墩身钢模板整体提升新工艺，具体介绍钢模板的结构形式、作业程序与特点、新工艺的优点以及所创造的经济效益，并展望新工艺的推广应用。文中以高速公路建设工程中的成功范例说明大型桥梁工程精心施工与创新设计的重要性。     

An experimental study on structural performance evaluation of steel wire-integrated deck plate

Recently, due to the decreased work term and the convenience of construction work, the steel wire-integrated deck plate has been widely used in the construction sites in Korea. Most of all, owing to its good stiffness and economic consideration, the steel wire-integrated deck plate system has become very popular in recent years. This research suggested the new-type shear connector that can perform the roles of vertical bar and shear connector at the same time to obtain safety on construction load of the steel wire-integrated deck plate and improvement on constructability, and used many variables such as the location of lattice end and diameter of the lattice bar to evaluate the structural safety of the steel wire-integrated deck plate in construction step. The test results show that the new-type shear connectors sufficiently perform the roles of the vertical bars.     

Load carrying capacity enhancement of cold formed steel walls using shotcreted steel sheets

Recently worldwide cold formed steel buildings are recognized as viable alternatives to reinforced concrete buildings especially in seismic areas. This is because they are lightweight (easy to handle), fast constructed, energy efficient (green houses), economical, dimensionally stable and they do not need skilled worker. Under vertical loading the design principles of these buildings are well established and codified, however, under lateral loadings such as wind and earthquake loads efficiently design is needed. In this paper a new sheathing technique uses shotcreted ribbed steel sheets is proposed to improve the stability and increase the lateral load carrying capacities of the CFS walls in order to withstand earthquake and wind loads safely. The idea is to sheath the outer side of CFS structure external walls with thin ribbed steel sheets, then shotcreted the sheets with cement or gypsum mortars. To test the concept full size wall specimens were prepared in the laboratory and tested under monotonic vertical and lateral loads. Some of the specimens were sheathed with the traditional fiber cement boards or gypsum boards with mat reinforcement, while the others were sheathed with the proposed technique. Test results indicates that the lateral load carrying capacities of the walls sheathed with the proposed technique increases by about two times compared with the walls sheathed with traditional boards. And under ultimate loads they fail in local failure modes rather than overall buckling failure modes which commonly occur in the walls sheathed with traditional boards.     

Approximate analytical solutions for diagonal reinforced timber-framed walls with fibre-plaster coating material

This paper provides approximate analytical solutions for diagonally reinforced timber-framed panel walls usually used as main bearing capacity elements in the construction of prefabricated timber structures. These walls can be mathematically treated as composite elements made of a timber frame and fibre-plaster boards as a coating material. As boards are the weakest part of the system they are reinforced with steel diagonals. The proposed approximate analytical models with the fictitious thickness and width of fibre-plaster boards enable simultaneously to consider the influence of inserted steel diagonals, flexibility of mechanical fasteners between the boards and the timber frame and any appearing cracks in the tensile area of the fibre-plaster boards. The obtained numerical results show good agreement with the measured experimental results.     

正交异性钢桥面板纵肋与桥面板连接细节的疲劳评估及修复措施

正交异性钢桥面板由于具有自重轻、极限承载力大等优点目前广泛应用于大、中跨径桥梁中,我国已建和在建的大跨径桥梁也大多采用正交异性钢桥面板.但由于正交异性钢桥面板结构构造复杂,受焊接残余应力影响大,钢桥面板直接位于车轮荷载的作用下,一些构造细节处极易发生疲劳开裂.以国内某大桥正交异性钢桥面板为例,针对纵肋与桥面板之间的疲劳...     

Experimental and numerical study on restrained composite slab during heating and cooling

In this paper, a series of fire tests on restrained composite slabs, carried out at the University of Manchester, is presented. A total of six composite slabs were tested under different fire scenarios, with different load ratios. The tests were particularly concerned with the variation of internal forces within the slabs during both heating and cooling phases. In addition to the testing programme, two separate nonlinear finite element models have been developed to simulate the thermal and mechanical behaviour of composite slabs during heating and cooling, which is introduced in detail in this paper. In the thermal analysis model, plane elements were adopted to obtain a detailed thermal behaviour. In the structural analysis model, the concrete, steel deck and mesh were simulated by solid elements, shell elements and truss elements respectively. The interaction between the concrete and steel sheet was simplified to spring elements. According to the experimental results and FE modelling, the behaviour of composite slabs was analysed in detail. At last, the parametric study was performed where the effect of concrete strength, steel deck thickness and mesh size was analysed.     

加热和冷却过程中约束复合板的试验及数值研究

在曼彻斯特大学,对约束复合板进行一系列耐火试验。在不同火灾场景下,对6块不同荷载比下的复合板进行试验,观察加热和冷却过程中板内力的变化。设计试验方案,建立两种不同的非线性有限元模型,模拟复合板在加热和冷却过程中的热学和力学性能。在热分析模型中,采用平面单元模拟。在结构分析中,混凝土、钢板、锚钉分别采用实体单元、壳单元、桁架单元模拟。混凝土和钢板间的连接简化为弹簧单元。根据试验结果和有限元计算结果,详细分析了复合板的性能。最后,进行参数研究,分析了混凝土强度、钢板厚度和锚钉尺寸的影响。     

大跨径桥梁钢桥面铺装设计

由于大跨径钢箱梁桥面铺装的使用条件、施工工艺、质量控制与要求的特殊性,因此对于特定的桥梁的桥面铺装均需作针对性的专题研究,以保证铺装设计和施工成功。总结了作者近10年对大跨径钢桥面铺装设计理论与方法设计的研究成果,包括铺装材料与结构、钢桥面铺装体系受力特性、疲劳特性、设计指标、轴载换算原则与方法、铺装体系整体优化设计方法、工程实施等技术,研究成果已在南京长江第二大桥、南京长江第三大桥、润扬长江公路大桥、苏通长江大桥和杭州湾大桥等10多座大型钢箱梁桥桥面铺装设计和铺装工程中应用。     

Full-scale long-term and ultimate experiments of simply-supported composite beams with steel deck

This paper presents the details of an experimental study carried out on two full-scale simply-supported composite steel-concrete beams to investigate their long-term behaviour and how this affects their ultimate response. The specimens were formed by a steel joist and a concrete slab with steel deck, and possessed identical spans and cross-sections. The ribs of the steel deck were orthogonal to the longitudinal axis of the steel joist, representing a secondary beam of a typical composite building flooring system. The beams were designed based on Australian guidelines with a degree of shear connection equal to 0.79. The samples were cast using unpropped construction. One specimen was kept unloaded for the entire duration of the tests. The second one was subjected to a sustained uniformly distributed load for about four months, after which it was loaded to failure. Particular attention was placed in this study on the occurrence of non-uniform shrinkage through the concrete thickness due to the presence of the profiled sheeting which prevented moisture egress to occur from the underside of the slab. Short- and long-term push-out tests were carried out to measure the response of the shear connectors over time. An analytical model was recommended to predict the long-term behaviour of composite beams with steel deck and its adequacy was validated against the reported experiments. For its simplicity, the proposed approach lends itself for design applications.