穿斗式木结构民居模拟地震振动台试验研究

为研究穿斗式木结构民居的抗震性能，以位于川西抗震设防烈度7度区的典型2层穿斗式民居为原型，对一个缩尺比例为1∶2的穿斗式木结构模型进行了模拟地震振动台试验。试验中选取汶川波、兰州波、Taft波和El Centro波作为地震动输入，实测了结构在地震作用下的自振频率、阻尼比、刚度、加速度反应、位移反应、剪力分布和应变的变化规律。试验结果表明：随着地震峰值加速度的增加，模型结构的自振频率和刚度下降，阻尼比增大，各层加速度放大系数介于0.286~1.383之间；浮搁于混凝土板上的柱脚的滑移在一定程度上衰减了传入上部结构的地震作用，第2层檐柱顶高度处的榫卯节点在振动过程中耗能作用明显；当输入峰值加速度为0.22g和0.40g时，模型晃动剧烈，最大层间位移角分别为1/65和1/35；当输入峰值加速度增至0.50g时，模型依然没有倒塌，表明穿斗式木结构具有良好的整体变形能力和抗倒塌能力。

Earthquake simulation shaking table test of column-and-tie wooden structure dwellings

In order to study the seismic performance of column-and-tie wooden structure dwellings, an earthquake simulation shaking table test was carried out on a 1∶2 model of a two-layer column-and-tie wooden structure built in the west Sichuan area with a seismic design intensity of seven degree. The Wenchuan wave, Lanzhou wave, El Centro wave and Taft wave were selected as input excitations. The natural frequency, damping ratio, stiffness, acceleration response, displacement response, shear force distribution and strain response of the structure under earthquake actions were obtained. The experimental results show that with the increase of earthquake peak acceleration, the natural frequency and stiffness of the model structure decreases, and the damping ratio increases. The acceleration amplification coefficient of each layer fluctuates between 0.286 and 1.383. The wooden frame is placed directly on the top of the concrete slab and slippage is noted at the bottom of the column, which to some extent reduces the earthquake action. The mortise-tenon joints at the height of the eaves have an obvious effect on the energy consumption during the vibration. When the input peak acceleration is 0.22g and 0.40g, the model shocks seriously, and the maximum inter-story drifts of the model is 1/65 and 1/35, respectively. When the input peak acceleration increases to 0.50g, the model does not collapse yet. It indicates that the column-and-tie wooden structure has good overall deformation ability and anti-collapse ability.