Understanding the development of cracks in masonry walls can provide insight into their capability for earthquake resistance. The\ncrack development is characterized by the displacement difference of the adjacent positions on masonry walls. In seismic oscillation,\nthe instantaneous dynamic displacements of multiple positions on masonry walls can warn of crack development and reflect the\npropagation of the seismic waves. For this reason, we proposed a monocular digital photography technique based on the PST-TBP\n(photographing scale transformation-time baseline parallax) method to monitor the instantaneous dynamic displacements of a\nmasonry wall in seismic oscillation outdoors. The seismic oscillation was simulated by impacting a suspended steel plate with a\nhammer and by simulation software ANSYS (analysis system), for comparative analysis. The results show that it is feasible to use\na hammer to impact a suspended steel plate to simulate the seismic oscillation as the stress concentration zones of the masonry\nwall model in ANSYS are consistent with the positions of destruction on the masonry wall, and that the crack development of the\nmasonry wall in the X-direction could be characterized by a sinusoid-like curve, which is consistent with previous studies. The\nPST-TBP method can improve the measurement accuracy as it corrects the parallax errors caused by the change of intrinsic and\nextrinsic parameters of a digital camera. South of the test masonry wall, the measurement errors of the PST-TBP method were\nshown to be 0.83mm and 0.84mm in the X- and Z-directions, respectively, and in the west, the measurement errors in the X- and\nZ-directions were 0.49mm and 0.44mm, respectively. This study provides a technical basis for monitoring the crack development\nof the real masonry structures in seismic oscillation outdoors to assess their safety and has significant implications for improving\nthe construction of masonry structures in earthquake-prone areas.
Loading....