Before revision: It happens at contact surfaces of a structure either with the ground The Geotechnical Earthquake Engineering Portal, or with adjacent structures Seismic Pounding between Adjacent Building Structures, or with gravitational waves from tsunami.
After revision: It happens at contact surfaces of a structure either with the ground The Geotechnical Earthquake Engineering Portal, or with adjacent structures Seismic Pounding between Adjacent Building Structures, or with gravity waves from tsunami.