Lateral Load Pattern Study of Pushover Analysis for Elevated Pile Foundation System of Bridges

Abstract:

Common lateral load patterns are introduced and the cap mass is changed in an attempt to study the equivalent fixing model of elevated pile foundation system.A comparison between pushover curves of these load patterns and results of nonlinear time history analysis is made.The result shows that,when cap mass is relatively large,cap inertial force is underestimated by using the above load patterns and through time history analysis,discrepancy of seismic capacity system against different earthquake waves is distinct,while capacity curves of the above patterns can't tell the difference.Given the cap inertial force of elevated pile foundation system is relatively great,double forces pattern is developed based on top single force pattern.At last,with the elevated pile foundation model of a floating type cable-stayed bridge,pushover analysis with common patterns and new pattern on longitudinal direction is made,then compared with nonlinear time history analysis.The result shows the new pattern works well.