摘要
Based on the difference of dynamic response to tilts between horizontal pendulums and vertical pendulum, spectral ratio method was applied to estimate the coseismic surface tilts deduced from strong motion records of Wenchuan earthquake 2008. The result shows that the ground surface tilts are generally less than 1 degree and mainly appears within 30 km to fault rupture surface traces, while rarely discovered in the area outside 100 km or root-mean-squared horizontal peak accelerations are less than 200 cm/s2. The frequency band influenced by tilts is less than 0.1 Hz.