PENINGKATAN DAKTILITAS HOLLOW PILE DENGAN PENAMBAHAN RATIO SPIRAL DAN BETON COR SETEMPAT

Abstract

The precast hollow pile is a type of pile which has been commonly used in Indonesia. According to SNI 03-1726-2012 Section 7.14.2.2.5, pile as part of the structure must exhibit ductile behavior to dissipate the amount of energy due to an earthquake. At one point, it is imperative to note that the major damage occurs at the transfer between fine soil and coarse soil, thereby an improvement must be considered. Regardless of this term, however, previous studies have shown the results and also concluded that hollow pile structure cannot undergo the ductile behavior. Therefore, this present work attempts to provide more insight into this structure to obtain the more ductile behavior which can meet the requirement as stated in the provision. This research was based on the prediction, both in analytical and numerical analyses, by using sectional design approach and finite element package ABAQUS and XTRACT. In this study, three types of hollow pile structural model were considered, namely Model 1 (control specimen), Model 2 (modified in increase of spiral volumetric ratio in maximum condition with regards to ACI and SNI), and Model 3 (additional filler inside the hollow section with concrete compressive strength of 67.8 MPa). The results highlighted that Model 2 had the improvement of displacement and curvature ductility by 82.1% and 96.84%, respectively, compared to the control specimen. On the other hand, Model 3 showed an increase in displacement ductility of 88.97% while curvature ductility of 137.15%. Based on overall results, it can be concluded that the utilization of filler concrete and the influence of spiral volumetric ratio can lead to the structural upgrade concerning ductility, although in fact, these improvements have not been able to satisfy the requirement in the provision.