PVC阳角条的抹灰应用

正在抹灰工程中墙、柱、梁、门窗口等墙面抹灰阳角,传统做法采用水泥砂浆抹护角,费时费力,质量不容易掌控。在抹灰面层的阳角部位镶嵌L形PVC阳角条,可以简化施工工序,加快施工速度,降低成本,提高工程质量,有效增加阳角的抗冲击性,防止阳角开裂,护角不生锈、不易老化。一、PVC阳角条介绍按传统做法时,抹灰工程中墙、柱、梁、门窗口等墙面在抹灰阳角采用水泥砂浆抹护角,不仅费时费力,而且质量不易控制。根据施工经验,在抹灰面层的阳角部位镶嵌L形PVC阳角条,可简化施工工序,加快施工速度,降低成本,提高工程质量,有效增加阳角的抗冲击性,防止阳角开裂,护角不生锈,不易老化,应用效果较好。     

带阳角深基坑变形及其影响因素分析

深基坑工程大型化、不规则趋势导致其变形影响因素更加复杂。为进一步提高不规则深基坑开挖过程的安全可靠性,借助有限元分析技术,对带阳角土岩组合深基坑变形影响因素进行分析。首先,构建带阳角深基坑有限元分析模型,其中,土体结构采用Mohr-Coulomb模型,岩体结构采用节理材料模型,锚杆、土钉与混凝土结构采用线弹性模型;然后,结合工程实际,通过阳角尺寸、覆土层厚度、锚杆布设等因素的影响分析,对带阳角土岩组合深基坑工程的变形特性进行研究,绘制了土岩组合深基坑变形与覆层土厚度关系曲线,以及不同阳角尺寸和不同覆土层厚度引起的深基坑水平位移变化规律曲线。研究表明,该深基坑阳角与阴角效应显著,阳角最大水平位移随覆土层厚度增加而增大,随护坡结构层厚度增加而减小,随锚杆直径增加而减小。研究可为同类工程的施工安全提供保障,使不规则深基坑工程施工更加科学、合理、经济、可靠。     

自制墙体钢木结合大模板的设计与应用

结合新疆石油管理局生产调度指挥中心工程具体情况及当地施工特点,剪力墙模板施工采用现场自制钢木结合大模板。针对工程施工难点,介绍了型钢龙骨加工方法、对拉大螺栓加工关键技术以及阴、阳角模板加工要点,并对大模板拼接处及阳角处加固提出合理有效的技术措施。结果表明,剪力墙基本达到清水混凝土的外观效果,取得了良好的经济效益和社会效益。     

不同开挖工况下软土基坑阳角壁变形及坑角效应

本文以某深基坑工程为依托,基于土拱理论和土压力等监测数据分析在基坑施工开挖施工过程中坑角效应对基坑土体和周边建筑物的影响。研究结果表明:在同一深度处,内部支撑对阳角处围护结构下部的抑制作用不明显,同一施工工况下凸出长度越大,基底隆起量越大。     

现浇混凝土楼梯施工工艺提升技术应用

现浇混凝土技术以其强度高、整体性强等独特优势在建筑领域中的应用越来越广泛,现浇楼梯踏步就是其中得到广泛应用的一种;现浇楼梯踏步板在现场施工中并不是什么复杂的工序,只需要按照施工图纸,按部就班的按照各道工序施工就行,可是要想将楼梯踏步板的成型质量控制好就不是件容易的事了。通过优化踏步模板配模、安装抹子限位装置、优化踏步模板加固方式、延迟踏步模板拆模时间等几个措施进行楼梯踏步模板施工工艺优化,可以有效避免楼梯踏步根部凹凸不平、阳角缺棱掉角、阳角不方正等质量通病问题。     

墙体面砖施工的改进

厨房、卫生间的墙面砖细部传统作法是，阳角处采用磨角的方式，然后对接在一起；在与门框、内窗框相交的部位，因有错台和缝隙，一般采用增加木贴脸的方法。这种作法的缺点是施工难度大，阳角易损坏。     

倒锥型外包角清水混凝土涂料施工技术

建筑外墙倒锥型构造以清水混凝土涂料代替清水混凝土施工,克服传统清水混凝土在异形结构的模板安装难度大、施工缝混凝土色差大、造价高等难题,简化了施工工序,且采用清水混凝土涂料可在结构施工后对结构表面平整度、阳角、倒锥斜面效果等细节进行处理,保证清水混凝土饰面的效果,提高饰面平整光洁度及整体效果。     

悬挑式脚手架特殊节点的技术研究

悬挑式脚手架作为项目建设过程中常用的外部防护操作架之一,虽然使用较为普遍,但许多施工企业在现场实施过程中,往往易对此特殊部位的节点忽视,造成成本投入增加,并且存在安全隐患。通过对传统悬挑架的技术优化,运用压梁、楼板加强等措施,解决了楼梯间、电梯井道、阳角等部位施工的难题,有效降低了施工成本,极大提高了架体的安全性。     

面砖阳角的改进做法

面砖阳角的改进做法面砖装修，洁净、美观、舒适，但阳角作法较差，明显影响效果。现经改进，改善了视觉效果。面砖阳角的传统作法有两种：（１）用大圆弧角砖粘贴。这种作法在较大的门窗口、空门洞、大阳角还可以，但阳角的两侧出现与墙面不相等同的两道线缝，对ｌｉｎ左...     

砖拱屋面粮仓的加固方案

结合工程实例,对墙体平面上单、双面裂缝,两墙体相交阴、阳角处裂缝,砖拱顶裂缝,屋面裂缝的施工加固方法及其施工步骤进行了详细的阐述,以延长结构的生命周期,对于土木工程可持续发展战略具有深远的意义。     

Nonlinear analysis of concrete-filled square stainless steel stub columns under axial compression

Concrete-filled stainless steel tubes (CFSST) can be considered as a new and innovative kind of composite construction technique, and have the potential to be used extensively in civil engineering. This paper employs a nonlinear analysis of square CFSST stub columns under axial compression. A three-dimensional nonlinear finite element (FE) model is developed using ABAQUS, where nonlinear material behaviour, enhanced strength corner properties of steel, and initial geometric imperfections are included. Close agreement is achieved between the test and FE results in terms of load-deformation response and ultimate strength. In light of the numerical results, the behaviour of stainless steel composite columns is compared with that of carbon steel composite columns. A simple model is proposed to calculate the ultimate strength of square CFSST stub columns.     

玻璃幕墙横梁立柱弹簧钢销新型连接施工技术

通过分析工程常用构件式玻璃幕墙框架立柱和横梁采用铝角码加螺栓或螺钉连接做法的缺陷,研发出一种主要采用不锈钢弹簧钢销及芯管与立柱连接固定弹簧插销新型连接技术,经过工程应用实践,该技术具有精度高、牢固、省材、施工简便等诸多优点,便于工程推广应用。     

Strength and ductility of corner materials in cold-formed stainless steel sections

The cold work from the manufacturing process of cold-formed steel members can enhance the strength but reduce the ductility of materials. Due to a high cost of stainless steels, it is desirable to utilize this enhanced strength and avoid the early fracture in cold-formed stainless steel members. The paper is concerned with the prediction of the enhanced stress–strain behaviour and reduced ductility of corner materials in cold-formed stainless steel sections. The enhanced strength of corner materials has been traditionally determined using empirical models. However, most of these empirical models are only able to predict the enhanced 0.2% proof strength, but are neither capable of predicting the enhanced ultimate strength nor able to determine the reduced ductility. This paper first presents a modified weighted-average method for predicting the post-ultimate stress–strain behaviour and the fracture strain for stainless steels. An advanced numerical approach is next presented for predicting the full-range stress–strain behaviour of corner materials in cold-formed stainless steel sections, in which the modified weighted-average method is incorporated. The accuracy of this approach is demonstrated by comparing its predictions with test results. The proposed approach is generally applicable to cold-worked materials for predicting their enhanced strength, reduced ductility and full-range stress–strain behaviour. The proposed method and numerical results can explain why and how the ultimate strength of cold-formed steels can be increased and how the post-ultimate stress–strain behaviour can be utilized through cold working.     

半刚性纯钢节点有限元模型的建立及分析

采用有限元软件ANSYS对齐平端板连接的梁柱纯钢节点进行建模,阐述了ANSYS有限元模型建立的几个关键,并根据有限元分析结果得出了齐平端板连接半刚性纯钢节点的弯矩与转角的关系曲线,从而为以后分析节点应力、变形能力等奠定了基础。     

Residual stresses in cold-rolled stainless steel hollow sections

Stainless steel exhibits a pronounced response to cold-work and heat input. As a result, the behaviour of structural stainless steel sections, as influenced by strength, ductility and residual stress presence, is sensitive to the precise means by which the sections are produced. This paper explores the presence and influence of residual stresses in cold-rolled stainless steel box sections using experimental and numerical techniques. In previous studies, residual stress magnitudes have been inferred from surface strain measurements and an assumed through-thickness stress distribution. In the present study, through-thickness residual stresses in cold-rolled stainless steel box sections have been measured directly by means of X-ray diffraction and their effect on structural behaviour has been carefully assessed through detailed non-linear numerical modelling. Geometric imperfections, flat and corner material properties and the average compressive response of stainless steel box sections were also examined experimentally and the results have been fully reported. From the X-ray diffraction measurements, it was concluded that the influence of through-thickness (bending) residual stresses in cold-rolled stainless steel box sections could be effectively represented by a rectangular stress block distribution. The developed ABAQUS numerical models included features such as non-linear material stress-strain characteristics, initial geometric imperfections, residual stresses (membrane and bending) and enhanced strength corner properties. The residual stresses, together with the corresponding plastic strains, were included in the FE models by means of the SIGINI and HARDINI Fortran subroutines. Of the two residual stress components, the bending residual stresses were found to be larger in magnitude and of greater (often positive) influence on the structural behaviour of thin-walled cold-formed stainless steel sections.     

A numerical investigation of local–overall interaction buckling of stainless steel lipped channel columns

A detailed finite element (FE) model is presented, which was developed with the aim of studying the interaction of local and overall buckling in stainless steel columns. The model incorporates non-linear stress–strain behaviour, anisotropy, enhanced corner properties and initial imperfections. The model was verified against a program of 29 laboratory tests on stainless steel lipped channels, described in a companion paper [Becque J, Rasmussen KJR. Experimental investigation of the interaction of local and overall buckling of stainless steel lipped channel columns. Journal of Constructional Steel Research 2009; 65(8–9): 1677–84] and yielded excellent predictions of ultimate strength and specimen behaviour.The FE model was further used in parametric studies, varying both the cross-sectional slenderness and the overall slenderness. Three stainless steel alloys were considered: AISI304, AISI430 and 3Cr12. The results are compared with the governing design rules of the Australian, North American and European standards for stainless steel structures.     

不锈钢覆面烟囱施工质量控制

介绍了某科学研究院放射性气体排风中心治理工程的烟囱采用了钢筋混凝土筒壁内贴不锈钢覆面的技术,针对烟囱筒壁与不锈钢覆面同时施工的技术及施工过程的监理控制进行了阐述,以期为类似的钢覆面工程质量控制工作积累经验。     

不锈钢复合钢板在铁路钢桥上的应用技术

我国高速铁路钢桥均采用正交异性板钢桥面有碴线路。为提高钢桥面的防腐与使用寿命,合肥铁路枢纽南环线钢桁梁的桥面板采用了具有较高的强度、塑性、韧性、疲劳性能及优良抗腐蚀性能的321-Q345q-D不锈钢复合钢板。针对钢桥面系结构设计特点及制作与安装工艺需要,依据TB10212-2009《铁路钢桥制造规范》、GB/T13148-2008《不锈钢复合钢板焊接技术要求》,对321-Q345q-D不锈钢复合钢板进行焊接工艺试验,其试验结果(数据)均满足设计与施工要求。经对不锈钢复合钢板的钢桥面制作与安装实践,对铁路钢桥推广应用不锈钢复合钢板提出改进建议。     

角部开孔钢筋混凝土板承载能力试验研究

对复杂支撑条件下角部开孔钢筋混凝土板进行了试验分析,重点研究了不同支撑条件及配筋对板的承载能力、位移、屈服线模式及反力的影响,并得出了具体的结论,从而促进角部开孔钢筋混凝土板承载能力的研究.     

奥氏体316不锈钢焊接工字形截面残余应力的试验研究

不锈钢在建筑结构中的应用逐渐增多,其中包括不锈钢屋盖结构、不锈钢桥梁、不锈钢墙面等结构中的应用。目前国内对不锈钢力学性能的研究相对较少,其中焊接残余应力是影响不锈钢构件焊接影响的一个重要因素,焊接残余应力的分布规律成为迫切需要研究的内容之一。采用分割条带法对奥氏体不锈钢316(06Cr17Ni12Mo2)包括6种截面的焊接工字型钢的纵向残余应力进行测量,通过对测量数据的分析,得到其残余应力的大小和分布特点,为进一步总结焊接不锈钢构件残余应力的分布和残余应力对不锈钢构件的承载力的影响提供了基础。