| dc.description.abstract | In the past, there have been many major earthquakes damaging bridges. Countries have modified their design codes after the earthquake. In addition, when engineers design the structure, almost using the design response spectrum to make sure about the force and check.
According to passed research, it has been proved that the rocking effect of the spread foundation can reduce the seismic force and extend the period. It will absorb the seismic energy due to the behavior of the soil entering plasticity, and can make the damage of the bottom of the bridge slight or no damage.
Nowadays, the United States and Japan has joined the rocking effect of the spread foundation into the specification for engineering. However, the code in Taiwan currently does not include the rocking effect and the spread foundation just can be designed as a fixed foundation without rocking. This makes the design conservative. Therefore, this study will refer to ASSHTO and Japan Specifications for Highway Bridge, and change the parameter like deck mass, column height, foundation size, and different forms of soil springs to make sure the respond of rocking effect. After drawing respond Spectrum and counting the percentages of absorbing the energy, found that the decreasing ratio of shear force at the bottom of the column under the non-linear soil spring is reduced by 19%. In addition, the study dismantled the acceleration of the deck to find out the meaning of the rocking respond. | en_US |