Shaking Table Test Study On Seismic Strengthened Two-story Brick-concrete Storefront

Low-rise storefronts are widely distributed with a huge number in rural areas.With inappropriate layout of structure, large openings in front of the house, incomplete seismic fortification measures, construction quality, the houses were badly damaged in past earthquakes. How to objectively assess seismic performance of this kind of buildings, and take some specific reconstruction measures, is an important work in the current rural construction and seismic disaster prevention field. As background to this article, the main research contents are as follows:First stage: by collecting and sorting filed survey data of our studying team, we comb through the architectural form and structural features of rural brick-concrete storefront. Based on this, we design a representative two-story brick-concrete storefront and make a 1/2 scale model. The results of shaking table test show that the model house is slightly damaged under 6 and 7 degree fortification earthquake, and walls are badly cracked under 8 degree fortification earthquake, the whole house is on the brink of collapse under 8.5 degree fortification earthquake.Second stage: the above model is restored and strengthened, then the shaking table test is conducted for the second time. According to ‘simple, feasible, safe,effective’ principles, the main reforcing and regenerating measures to the model house are as follows: using punctuate grouting treatment for full-length cracks on the cross wall, temporary structures are set up to support the bottom beam, the bottom badly damaged wall between windows is dismantled and rebuild. Based on this, the lengthwise backwalls are strengthened with reinforcing mesh. The shaking table test results after reinforcement show that the model house has no visible crack under 8degree fortification earthquake, and the corners of the windows are slightly cracked under 8.5 degree fortification earthquake, the reinforced lengthwise walls have full-length cracks but can continue to bear load under 9 degree fortification earthquake,the walls are severely damaged but not collapse under 9 degree strong earthquake.In addition to record macroscopic seismic damage, this paper record natural vibration behaviors, acceleration and displacement responses of model before and after reinforcement, and the results in-depth analysis and research.General conclusions of this paper: As seismic fortification measures were incomplete and inappropriate layout of structure, the two-story brick-concrete storefronts can hardly avoid collapse under strong earthquake. After being strengthened with reinforcing mesh, the two-story brick-concrete storefronts are plenty to meet the requirement of the 3-level design.