Abstract
Concern about the dam safety of aged large dams has been growing after the 1995 Hyougokennanbu Earthquake. The objective of this study is to investigate the static behavior of an aged arch dam by in-situ tests. The followings are main results obtained by the tests and the analysis. 1. At contraction joints of the dam, axial deformation is large but the other deformations, the lateral and the vertical deformations are very small. 2. The fine cracks observed on the downstream surface were caused by the thermal stress in winter and have no effects on the stability of the dam. 3. The analysis can give a good estimation about the behavior of an aged arch dam caused by water level change.
