施工活荷载效应的影响面及其应用  

Influence surfaces of construction live load effects and application

作　　者：谢楠[1] 刘博辉[1] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《建筑结构学报》2012年第12期136-141,共6页Journal of Building Structures

基　　金：国家自然科学基金项目(51078018);2009年住房和城乡建设部安全质量监督专项经费项目(2009-9)

摘　　要：对模板支撑体系中立杆承受的施工活荷载估计不足是立杆失稳主要原因之一,而影响面是确定施工活荷载的最不利位置、快速计算荷载效应以及统计分析的基础,基于此,选取两种现浇混凝土板和混凝土梁板的模板支撑体系中有代表性的立杆作为研究对象,采用机动法得出其轴力的影响面并给出影响面拟合表达式和正负影响区域,计算出正负影响区域的等效影响面高度。基于影响面,提出了集中荷载、局部线荷载和局部均布荷载作用下的最大荷载效应计算式,将其用于计算大型布料设备重量、新浇筑混凝土重量和钢筋捆重量所产生的最大轴力,并与按JGJ 162—2008《建筑施工模板安全技术规范》所给方法的计算结果进行比较,结果表明规范计算结果偏小。据此提出了保证施工阶段结构安全的一些建议。Underestimation of construction live load applied on supporters of formwork is one of main causes of the instability of supporters.Influence surfaces are the foundations for determining the unfavorable load location,calculating fast the load effect and statistical analysis of load.So,in this paper,the two representative kinds of supporters for concrete slab and concrete beam-slab were selected to be research subjects.The influence surfaces of axial forces on supporters were obtained in terms of the kinematic method and fitted by some functions.The positive and negative influence regions of load effects and equivalent heights of the influence surface in different influence regions were given respectively.On the Basis of the influence surfaces,formulas for calculating largest load effects of concentrated load,line load and distributed load were proposed respectively,and were applied to calculate the largest axial forces on supporters under the actions of concrete spreader,plastic concrete and a bound of reinforcement.From comparison with calculation results of the Chinese Standard,it can be seen that the results from the Standard are relatively smaller.Some suggestions were given to ensure the structural safety during construction.

关 键 词：施工活荷载 影响面 模板支撑体系 机动法 立杆轴力 最大活荷载效应 

分 类 号：TU312.1[建筑科学—结构工程] TU311.41