The Experimental Seismic Performance of Positive and Negative Batter in a 2 x 2 Piles Group in Loose Sand

In the event of an earthquake, pile foundations help to keep a structure stable. Batter piles, which are a sort of angled foundation, can resist both vertical and horizontal loads better than a typical vertical pile. The primary objective of this research is to address the seismic response of negatively battered piles in 2 × 2 pile groups embedded in loose sand through an experimental approach. The experimental study used 2 × 2 pile groups embedded in a loose sandy soil with 31.2% relative density, and seismic loading was replicated using a shaking table. Ground motion in the El Centro and Kobe earthquakes was applied to piles with batter angles of -5°, 0°, and +5°. The purpose was to assess and contrast the case of a negatively battered pile with vertical and positively battered piles, about the lateral and vertical displacements, and the acceleration. Experimental findings demonstrated that negative battering notably amplifies pile group displacements under seismic excitation. Specifically, for the El Centro earthquake, changing the batter angle from 0° to 5° increased the maximum lateral displacement by 24.287%, while adjusting it from 0° to +5° reduced it by 3.877%. Similarly, vertical displacement rose by 19.923% for the negatively battered piles, whereas positive battering resulted in a 7.511% reduction in lateral displacement for the same event.