两层轻型木结构足尺房屋模型模拟地震振动台试验研究

Shake table tests of a two-storey light wood framed house

轻型木结构房屋在既往的地震中表现出良好的抗震性能,同时也存在某些方面的不足。对一个两层、足尺、长宽高为6m×6m×6.3m的木框架房屋进行了67个工况的振动台试验,考虑了一层横墙的门洞宽度变化和结构平面布置不对称等研究参数。试验结果表明:在0.2g以下的地震中,模型处于弹性状态;在0.55g的地震中,即使经过多次重复地震,并且一层开洞率达到60%,模型结构仍然不会发生倒塌;结构布置不对称时,结构的加速度和位移反应均较对称结构强烈,并且存在明显的扭转效应。对称结构在0.1g、0.2g和0.4g的地震中,模型结构的最大层间位移角约为1/500、1/250和1/80。试验研究的结果表明,与模型结构类似的对称轻型木结构房屋能够满足我国建筑抗震设计规范(GB50011-2001)中的8度抗震设防要求。

Light wood framed houses, with their shortcomings, have performed well in past earthquakes. The specimen for shake table tests is a full size two-storey light wood framed house, 6.0m by 6.0m in plan, and 6.3m in height. Both symmetrical configurations with three types of opening sizes and asymmetrical configurations are tested. The test results indicate that the specimens performed elastically and had no visual damage for 0.2g PGA. The tested symmetric building with progressively lager openings can withstand successive applications of three different seismic ground motions in the order of 0.55g PGA without collapse. For the asymmetrical building, the response of acceleration and displacement of specimen were larger than that for symmetrical building. Inter-story drift in the first story was generally bellow 1/500, 1/250 and 1/80 at nominal levels of 0.1g, 0.2g and 0.4g peak table acceleration. The symmetrical light wood framed house specimen can meet the requirements for the seismic intensity of 8 as described in the China Seismic Design Code （GB 50011-2001 ） .