Seismic specific spectrum site based on code
One Taft Tower is a 40-story residential building located on Taft Avenue in Malate, Manila. The building will mainly have two uses: luxury residences and commercial use. The project includes a spa and a swimming pool on the roof of the building. The main challenge of the building is that it is located only 5 kilometres away from an active fault. The Philippines is located in the Pacific Ring of Fire and is characterized by the concentration of some of the most important subduction zones in the world, causing intense seismic activity in the areas covered.
The tower is conceived in structural concrete, with its main lateral system composed of shear walls located in the central core. The foundation system consists of 65 piles 50 meters deep and 1.5 meters in diameter.
As part of our mission, we conducted “Value Engineering” studies to provide CITYLAND (the owner) with an optimal and efficient design that ensures safety in the event of a severe earthquake.
The DYNAMIS analysis took into account not only the effects of fault proximity by introducing a pulse function in the synthetic accelerograms used, but also considered the kinematic and inertial effects generated by the soil-structure interaction. The analysis of the soil-structure interaction accurately incorporates the effects of soil deformation, the flexibility provided to the building and the increase of the overall damping of the whole system. These effects were considered according to the NSCP 2010 local code. The base shear was reduced by more than 30%.
The foundation system (piles) was also designed to withstand the forces generated by the lateral spreading in case of liquefaction of the soil in the upper layers. The San Francisco Engineering firm ARUP, specifically the Applied Technology Council (ATC) team, participated in the project as a peer reviewer.
Our client, CITYLAND, appreciated our “Value Engineering” mission where the seismic input was obtained ensuring a safe and an optimum structural design.