共查询到19条相似文献，搜索用时 217 毫秒
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混凝土斜拉桥采用挂篮施工主梁时,挂篮底部行走轮对主梁底板产生巨大的竖向反力.混凝土底板、肋板可能在此反力作用下发生局部承压开裂破坏,需进行安全验算.行走轮与底板的接触区域是未知的,混凝土的受力变形均由接触区域决定.为寻求简单适用的计算方法,采用弹性接触Hertz理论,求解行走轮与混凝土板接触区域大小及应力分布,在此基础上应用规范推荐公式进行底板及肋板的抗裂安全验算.算例表明,该方法是可行的,可以简便地进行主梁底板的局部承压安全验算. 相似文献
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竹胶合板模板的设计与计算 总被引：1，自引：0，他引：1
温新辉 《荆门职业技术学院学报》2004,19(6):17-20
针对竹胶合板模板的变形问题．提出模板设计与计算中应注意的问题，指出竹模板设计必须按照《建筑结构设计规范统一标准》。根据我国结构设计采用极限状态设计的要求．参照《木结构设计规范》确定竹胶合板的设计强度，并考虑进行模板变形的受弯构件承载力验算和挠度验算来予以解决． 相似文献
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厚度2.8 m的现浇混凝土楼板的重量远大于危险性较大模板支撑体系规定的荷载值,采用通常的模板支撑架不能满足立杆稳定性验算的要求。设计超厚板独立支撑模板支撑体系,在模板支撑架立杆上布置应变测点,采集浇筑混凝土过程中的应变数据。分析显示:局部测点应变值偏大与模架下方立杆偏心受压有关,浇筑混凝土过程中出现瞬间动载远超静态荷载应变允许值等现象。建议应用类似模板支撑结构时,设计更为合理的立杆上方承载装置;浇筑和振捣混凝土形成的动荷载是模板支撑架的安全隐患,有必要进一步研究动荷载与模板支撑架稳定性之间的关系。 相似文献
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杜鹃 《石家庄铁路职业技术学院学报》2015,(4):31-35
针对菩萨崖大桥的实际情况,设计空心薄壁高墩模板,并进行强度、刚度验算,计算结果表明设计方案是可行的。工程实践表明所采用模板方案是合理的,保证工程的顺利进行。 相似文献
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冯宇 《石家庄铁路职业技术学院学报》2023,(1):69-74
本文以北京地铁28号线京广桥站为例,介绍了该站南侧换乘厅侧墙单侧支架模板的施工工艺流程,得益于稳定的模板支撑体系和实用、安全、经济的特点,该技术在地铁建设中广泛应用。依据规范和土层特性确定对侧墙土压力,按照荷载结构模式进行面板、几字梁、横向背楞、单侧支架受力性能的安全性验算,验证结果表明施工方案安全可行,为类似工程提供参考。 相似文献
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黄玉宁郑永乾赖鹏松 《福建工程学院学报》2020,(4):329-335
采用有限元软件ABAQUS建立了不同加载角T形带肋和多室钢管混凝土压弯构件的计算模型,数值计算结果与试验结果吻合良好。对影响T形钢管混凝土柱水平荷载P-水平位移Δ关系曲线的参数进行分析,结果表明:加载角为0°时,T形钢管混凝土构件的承载力最低,在67.5°负向加载时,构件的承载力最大,比0°加载角构件大13%左右,加载角为45°~90°间承载力总体上差别不大。随着钢管屈服强度、混凝土抗压强度、钢管长厚比、带肋和多室T形钢管混凝土构件在斜向加载的承载力增加,在传统钢管混凝土基础上,提出了适用于不同加载角带肋和多室T形钢管混凝土压弯构件的承载力设计方法,简化计算公式与有限元结果、试验结果均吻合较好。 相似文献
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本文根据“混凝土设计规范”(GBJ10-89),结合多年的教学实践和施工中出现的问题,对裂缝宽度验算公式做了一定程度的简化,供大家探讨。 相似文献
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为了减少坝前填垫层料的超填工程量,简化混凝土面板施工前的削坡处理、斜坡碾压以及护坡砂浆施工等繁琐工序,给混凝土面板施工提供一个相对平整、均质的支托基础面,同时也为施工期间的防洪度汛提供一个防止雨水冲刷的稳固坡面,最大限度地延长筑坝施工时段,减轻高强度筑坝压力,确保大坝安全度汛,采用混凝土挤压边墙这一新技术、新工艺代替上游护坡砂浆施工不失为有效措施. 相似文献
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Wall cracking and mold expanding due to concrete vibrations can be effectively solved through the application of precast normal-concrete composite shear walls infilled with self-compacting concrete (SCC). However, the high liquidity of SCC will induce a higher lateral pressure. Therefore, it is important to obtain a better understanding of the template lateral pressure. In this work, nine composite shear walls were experimentally investigated, focusing on the effects of two parameters, i.e., the casting rate and the section width of the formwork. The time-varying pressure was monitored during the SCC pouring. It is found that the increase of casting rate from 3.2 m/h to 10.3 m/h resulted in a higher maximum lateral pressure. The higher casting rate led to a longer time required for the lateral pressure to drop to a steady value. There was no correlation between the section width and the rate of decrease in the initial formwork pressure and stable value. Based on the test results, a formula considering the effect of casting speed for the calculation of SCC formwork pressure was established to fill the gap in the current standards and for engineering applications. 相似文献
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滑模技术在水利水电工程中常用于大体积混凝土施工,在地下洞室混凝土衬砌很少涉及,特别是对于小断面地下洞室混凝土衬砌更是未曾采用。对于滑模这种先进的施工技术如何应用于小断面地下洞室混凝土衬砌,本文结合工程实际情况,对液压滑模系统的结构设计和施工方法进行了探讨和总结,为滑模技术在小断面地下洞室混凝土衬砌提供了实际经验。 相似文献
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在综述国内外大量砼工程模板技术的基础上，对砼工程模板技术现状进行深入分析，并对砼工程模板技术未来进行展望。 相似文献
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边墙模板台车是在钢模板的基础上,通过改进支架体系,使支架体系形成整体,然后通过可调液压油缸使钢模板和支架体系相连,并加入行走装置,形成一种自行式的模板台车。台车的外轮廓与地铁边墙理论内轮廓面一致,通过封堵模板开挖面端部的开挖面,使模板与边墙形成封闭的环形仓,之后灌注混凝土完成边墙的衬砌。由于灌注过程中台车受到灌注混凝土浮力的作用,因此不可能一次灌注全部完成,需要对灌注划分工况逐一分析。 相似文献
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HAO Qing-duo WANG Yan-lei ZHANG Zhi-chun OU Jin-ping 《浙江大学学报(A卷英文版)》2007,8(9):1356-1365
Based on the Canadian Standards Association (CSA) criteria,105 pullout specimens were tested to investigate the effect of different rib geometries on bond strength of glass fiber reinforced polymer (GFRP) rebars embedded in concrete. Two kinds of conventional reinforcing rebars were also studied for comparison. Each rebar was embedded in a 150 mm concrete cube,with the embedded length being four times the rebar diameter. The experimental parameters were the rebar type,rebar component,rebar diameter,rebar surface texture,rib height,rib spacing and rib width. Theoretical analysis was also carried out to explain the experimental phenomena and results. The experimental and theoretical results indicated that the bond strength of GFRP rebars was about 13%～35% lower than that of steel rebars. The bond strength and bond-slip behavior of the specially machined rebars varied with the rebar type,rebar diameter,rebar surface texture,rib height,rib spacing and rib width. Using the results,design recom-mendations were made concerning optimum rib geometries of GFRP ribbed rebars with superior bond-slip characteristics,which concluded that the optimal rib spacing of ribbed rebars is the same as the rebar diameter,and that the optimal rib height is 6% of the rebar diameter. 相似文献
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设置加强筋有利减小注塑件壁厚并降低充模阻力,但由于加强筋与塑件基体壁厚有差异会造成冷却和收缩不均,从而使塑件产生翘曲变形．借助Moldflow软件对典型板状注塑件进行模拟注塑成型分析,通过改变加强筋的尺寸研究加强筋的高度及厚度对塑件收缩和翘曲变形的影响规律．基于翘曲变形量优化设计加强筋尺寸,结果表明：典型板状塑件的加强筋的高度为塑件厚度的两倍,加强筋厚度应小于塑件厚度的0．5倍,此时塑件的翘曲变形量较小． 相似文献
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The blast resistance of structures used in buildings needs to be investigated due to the increased threat of a terrorist attack. The damage done by Composition B or Powergel to steel fibre reinforced reactive powder concrete (SFRPC) panels and ordinary reinforced concrete (RC) panels of equivalent static flexural strength is compared. A 0.5 kg charge was detonated at a distance of 0.1 m from the 1.3 m×1.0 m×0. 1 m (thick) panels, which were simply supported and spaning 1.3m. Dynamic displacement measurements, high-speed video recording and visual examination of the panels for spall and breach were undertaken. The SFRPC panels withstood the bare charge blast better than the reinforced ordinary concrete panels. Neither type of panel was breached using a 0.5 kg charge. The RC panel exhibited more spalling when Composition B was used. Under successive Composition B loading conditions, the RC panel was breached. In comparison the SFRPC panel was not breached. Exposure to fragmenting charge loading conditions confirmed these performance differences between the SFRPC panel and the reinforced ordinary concrete panel. 相似文献
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本文介绍荷载传递法在高层建筑结构转换层施工中的应用, 利用组合门架作为主支撑, 可调支撑加胶合板作为底模, 辅以相应的钢筋绑扎安装、混凝土浇筑措施, 成功完成大体积混凝土转换层的施工 相似文献