北京农村砖木结构抗震加固动力特性分析

Dynamic characteristic analysis on seismic strengthening of existing rural masonry-timber buildings in Beijing

根据北京地区既有农村住宅典型砖木结构(木柱支撑,木屋盖,外砖墙)的抗震性能特点以及农宅砖木结构未抗震加固模型的振动台试验损伤特征,结合北京地区8度抗震设防的要求,提出以下加固结构方案:①配筋砂浆带圈梁、②前檐加设钢门窗框、③房屋四角钢丝网砂浆加固,并设计2/3大比例缩尺模型,进行了8个工况振动台试验,研究了北京地区既有农村住宅单层砖木结构房屋上述抗震加固方法的有效性。通过与未加固模型的振动台试验损伤结果、动力特性、动力反应和频谱分析比较,验证了提出的加固方案的抗震性能和可行性。振动台试验结果表明:加固后模型达到了"小震不坏、中震可修、大震不倒"的抗震设防目标,为制定这类结构的抗震加固方案提供了依据。

Based on the seismic performance and shaking-table test of damage characteristics of typical single-story masonry-timber buildings in Beijing, some seismic strengthening methods were proposed： ① application of ring beams with reinforced polymer-modified mortar, ② application of steel door window frames to front eaves, and ③ strengthening four building corners by cement mortar reinforced with steel mesh. In addition, to study the seismic behaviors and effectiveness of the above seismic strengthening methods for single-story masonry-timber structure, a series of large-scale （2/3） shaking table tests were carried out to evaluate the seismic performance of the reinforced buildings. The shaking table test results indicate that, the strengthening methods could effectively improve the seismic performance of such masonry-timber structures, and the strengthened specimen could achieve the design objective of ＂no damages under minor earthquakes, repairable damages under moderate earthquakes, and no collapses under rare earthquakes, by comparing with the testing damage conditions, dynamic characteristics, spectrum analysis.