Abstract: | In 1890, a twelve-story octagonal sight-seeing tower was constructed as a high rise building in Tokyo Asakusa Park. In 1923, however, the top of the tower from the eighth floor up collapsed due to the Great Kanto Earthquake. In order to raise public interest in disaster prevention, we performed as a virtual experiment a conceptual attempt to save the tower without fundamentally changing its architectural characteristics by applying the most advanced structural control techniques. In the simulation, the top of the tower from the eighth floor experienced, almost exactly as described in historical record, a shear fracture during the initial period of principal shock. The modified Ryounkaku Tower would have ensured a comfortable margin of safety even against earthquakes more severe than the Great Kanto Earthquake in 1923. |