Experimental Seismic Response of a Damaged Brick Cave Dwelling Repaired Using a Cement Mortar Coating with Polypropylene Packing Strap Mesh

Millions of people still live in cave dwellings in China and around the world. Due to high risk of earthquakes combined with material deterioration, cave dwellings exhibit poor seismic performance. Accordingly, a low-cost and highly efficient repair technique for damaged brick cave dwellings is needed. This paper presents shake table testing results for seismically damaged 1:4-scale brick cave dwelling models repaired using a cement mortar coating with polypropylene packing strap mesh. The seismic response of the repaired cave dwellings is presented in terms of damping ratio, acceleration, interstory drift, torsion angle, base shear, and hysteretic energy dissipation. Full peeling off between the cave sidewalls and the back wall as well as the plastic hinge at the bottom of the sidewalls led to the failure of the repaired cave dwellings. The damping ratios of the repaired cave dwelling models in the x- and y-directions were 2.23 and 2.74 times that of the initial values, respectively. The maximum story drift and horizontal torsion angle of the models at peak ground acceleration (PGA)=1.00 g were 1/29 and 0.0015 rad, respectively. The use of a cement mortar coating with polypropylene (PP) packing strap mesh to repair the brick cave structure resulted in acceptable seismic performance.