IMPROVEMENT OF SEISMIC PERFORMANCE OF WHARVES INCLUDING BATTER PILES

Pile supported deck systems are prevalent structural system for wharves and piers. Pile groups are often required to support loads applied perpendicular to their longitudinal axes. Lateral load resistance is independent of axial effects. However, high axial compression and lateral displacements may interact with together and increase lateral displacements, bending moments and shear forces. In seismically active regions, batter piles are installed to support the horizontal loads by a component of the axial pile-soil resistance in addition to the lateral resistance ofpiles. Several case studies show that batter piles head connections may be overstressed if the pile group is not designed using an appropriate method. Batter piles tend to attract significantly larger earthquake loads than vertical piles. Therefore, specific considerations are required for the design of batter piles. Based upon a nonlinear soil-structure interaction analysis, the presented paper discusses the role of batter piles in the seismic performance of wharves. Because the earthquake loads transmitted to the batter piles could be very large, a structural fuse is introduced. The fuse allows plastic yielding of the batter pile head connection to be transmitted to it. In this scheme, damages due to earthquake are concentrated in this replaceable member and amendment difficulties are minimized. Finally, a sample wharf with batter piles and the introduced structural fuse is examined. A nonlinear static analysis is applied and the performance of this structural fuse against earthquake loads is evaluated. The presented paper concludes the introduced structural fuses could improve the seismic performance of batter piles in wharves.

Keywords:

Batter Piles , Pile-Supported Wharves , Structural Fuse , Pile-Soil Interaction , Earthquake Loads , Nonlinear Static Analysis