Peak Ground Acceleration Attenuation Relationship of Wenchuan 8.0 Earthquake

The strong motion recordings at 107 observation stations from Wenchuan 8.0 earthquake in 2008 are analyzed with the statistics method.For comparising the ground motions in two different regions—the hanging wall and footwall regions,the 107 observation stations are divided into the two regions.There are 77 stations in the hanging wall region and others in the footwall region.The acceleration attenuation relationships of strong motions were analyzed by the least squares method.Two horizontal and Two vertical acceleration attenuation relationships are obtained.Based on these relationships,the characteristics of strong motions,including the horizontal and vertical acceleration attenuations,the variation of ratio of peak accelerations in horizontal and vertical motions,and the hanging wall and footwall effects are discussed to find out the difference of strong motions in the two regions.Finally,attenuation models are compared with some well-known attenuation relationships.