北京市既有农村住宅砖木结构加固前后振动台试验研究

以北京市既有农村住宅广泛采用的单层砖木结构房屋为研究对象，通过加固前后2个大比例尺模型的振动台试验，研究抗震加固方法的有效性。试验结果表明：未加固房屋由于前后纵墙抗侧刚度相差大，纵向地震作用下前纵墙侧移大，砖柱损伤严重；山墙平面外变形大，形成贯穿的斜向裂缝；8度小震作用下墙体开裂，中震作用下墙体损伤严重，大震作用下模型结构濒于倒塌。根据试验结果，提出了抗震加固方法，包括加设钢门窗框及钢板圈梁，采用钢筋网砂浆面层加固山墙和砖柱。振动台试验表明，上述加固方法显著提高了此类砖木结构房屋的抗震能力，加固后结构达到“小震不坏、中震可修、大震不倒”的抗震设防目标。

Shaking table test of unretrofitted and retrofitted brick-wood structures representative of existing rural buildings in Beijing

This paper presents seismic retrofit for the single-story brick-wood structure representative of existing rural buildings in Beijing. The retrofitting effectiveness was examined through large-scale shaking table tests on the unretrofitted and retrofitted specimens. The test results indicate that, for the unretrofitted specimen, the front brick columns deform and damage severely when subjected to the longitudinal motions, because large of lateral stiffnesses difference exists between the front and back longitudinal walls. The brick gables experience significant out-of-plane deformation, resulting in diagonal cracks. The unretrofitted specimen is cracked under minor earthquakes, significantly damaged under design basis earthquakes, and approaches to collapse under rare earthquakes. The method of seismic retrofit was proposed based on the test results of the unretrofitted specimen, including the addition of a steel doorframe, steel window frames and steel plate collar beams, and the strengthening of the brick gables and columns by cement mortar reinforced with steel mesh. Shaking table test results show that the retrofit method significantly improves the earthquake-resistant capacity of the brick-wood building structure, and the retrofitted specimen can achieve the design objective of ‘operational under minor earthquakes, repairable damage under design basis earthquakes, and collapse prevention under rare earthquakes’.