Shaking table test on brick masonry farmhouse strengthened by polypropylene grid cement mortar coating
In order to improve the seismic performance of brick masonry farmhouse,the strengthening method of polypropylene grid cement mortar coating was proposed.A typical single-story and double-bay brick masonry farmhouses in Lantian County,Shaanxi Province was selected for seismic strengthening,and the shaking table tests were carried out on the strengthened model.El Centro wave,Taft wave and artificial wave were chosen as input earthquake waves.The seismic failure pattern,dynamic characteristics and dynamic response,such as acceleration,displacement,torsion,base shear,as well as hysteretic curves and cumulative dissipation were obtained and analyzed.The results show that,with the peak acceleration of the input earthquake waves,the natural frequency and acceleration amplification factor of the strengthened model decrease,and the damping ratio increase.The maximum inter-story drift occurs at the longitudinal section of gable ridge,and the maximum inter-story drift ratios of the strengthened model were 1/5 439,1/2 195 and 1/522 under eight degree frequent earthquake,design basis earthquake and maximum considered earthquake,respectively.When the peak acceleration of the input earthquake waves reached 1.0g,the maximum inter-story drift ratio was 1/112,and the obvious convexity occurred at the middle of the gable.The strengthened model was twisted under the earthquake,and the maximum horizontal torsion angle reached 0.0037 rad.The strengthening method of polypropylene grid cement mortar coating can not only improve the deformation capacity and energy dissipation capacity of the brick masonry farmhouse significantly,but also have the low strengthening cost.It can be popularized and applied in the seismic strengthening of brick masonry farmhouses in the high seismic intensity areas.