Numerical Analysis of the Stability of Bridge Foundation Pile under Earthquakes Effect

Abstract

This study was chosen because of the entry of our regions into the seismic zone recently, where Diyala governorate was hit by the Halabja earthquake in 2017 by 7.3Mw. Therefore, the impact of earthquakes will be studied on the AL-Mafraq bridge foundations piles located in Iraq- east of Baghdad in Diyala Governorate and the extent of its resistance to the Halabjah, EL-Centro, and Kobe earthquakes with acceleration 0.1g, 0.34g, and 0.58g respectively. After modeling and performing the analysis by using Midas Gts-Nx software, the settlement (mm) results at nine nodes (four nodes for the pile cap and five nodes for the piles) were obtained for each of Halabjah, EL-Centro, and Kobe earthquakes to know the resistance of the bridge foundation and which intensity leads to the failure happen. After conducting the analysis, I found the maximum settlement is equal to 11.95 mm with a time of 443 sec at node 3 resulting from the Halabjah seismic, and 49.47 mm from the EL-Centro seismic with a time of 254 sec at node 3. They are within the allowable limits of settlements, but the maximum settlement resulting from the Kobe earthquake equals 359.9 mm with a time of 565 sec at node 3. So, the Kobe earthquake led to failure in the pile's foundation Halabjah earthquake and Centro did not affect the stability of the pile's foundation, Based on Terzaki's theory 1943.