砌体房屋封闭式阳台挑梁施工过程荷载累积效应分析

Analysis on Loads Accumulation Effect During Construction of Enclosed Balcony Cantilever Beams of Masonry Buildings

为扩大使用面积,多层砌体房屋2层及以上各层普遍设封闭式悬挑阳台。由于此阳台的封闭墙体一般按承重墙施工,可能存在荷载逐层传递累积效应而导致最下层挑梁承载力不足。以某在建5层砌体结构房屋为例,采用ABAQUS分别模拟封闭悬挑阳台墙体采用承重墙、填充墙2种形式,对比二者最下层挑梁的内力和变形差异。分析结果表明,按承重墙砌筑阳台围护墙体时,存在一定的荷载逐层传递累积效应,但仅限于相邻一个楼层间;2种方法的挑梁弯矩和变形差异较小,但剪力差异达35%;挑梁及围护墙体组合成悬挑墙梁,墙体的内拱效应、大窗洞隔断传力路径是荷载逐层传递累积效应不显著的主要原因;在一定条件下,按承重墙施工仍可行,但设计时应注意校核挑梁的抗剪承载力。

In order to expand the use of area,multi-storey masonry buildings with 2 storeys and above are commonly provided with closed cantilever balconies.As the closed walls of these balconies are generally constructed as load-bearing walls,there may be a cumulative effect of load transfer from floor to floor resulting in insufficient load-bearing capacity of the lowest floor cantilevers.Taking a 5-storey masonry building under construction as an example,ABAQUS was used to simulate the construction of its closed cantilever balcony wall using 2 methods of load bearing wall and infill wall respectively,and to compare the difference in internal force and deformation of the lowermost cantilever beam between the two.The results of the analysis show that there is a certain cumulative effect of load transfer from floor to floor when the closed balcony retaining wall is built according to the load-bearing wall,but only between one adjacent floor.The difference in bending moment and deflection between the 2 methods is small,but the difference in shear force is up to 35%.The combination of the cantilever beam and the retaining wall into a cantilever wall beam,the internal arch effect of the wall,and the large window opening isolating the transfer path are the main reasons why the cumulative effect of load transfer layer by layer is not significant.Under certain conditions,it is still feasible to construct as a load-bearing wall,but care should be taken in the design to check the shear load capacity of the cantilever beams.