2012 Volume 7 Issue 1 Pages 163-173
The severe seismic damage to the large scale filled-valley residential area in Sendai City was caused by the 2011 off the Pacific coast of Tohoku Earthquake. First, this report shows the result of seismic damage research in the filled-valley residential area (called Nankodai) in Sendai City. Next, the result of seismic damage research is arranged paying attention to geographical factor, and the influence of the angle of old topography, the angle of ground surface, and the thickness of filled-valley upon the seismic damage is considered. The following results were obtained through this research. (1) The ratios per an area of fully damaged house in filled-valley area and boundary area were more than 25 times of that in cutting ground area. (2) About 60 % of fully or half damaged house were caused by ground crack. (3) The ratio of fully or half damaged house to all houses was 3 % in filled-valley area, 5 % in boundary area, and 32 % in filled-valley side a little of boundary area. (4) Ground cracks were classified into 3 types, and it was shown that each type of cracks had been controlled by the angle of old topography, the angle of ground surface, and the thickness of filled-valley.
