Analisa Daya Dukung Pondasi Tiang dengan Variasi Diameter dan Jarak pada Pengembangan Dermaga Curah Cair Benoa Bali

Abstract

Dermaga Curah Cair Benoa Bali is a port facility currently under development, making the reliability of its pile foundation an important aspect in supporting loading and unloading operations. This study aims to analyze the influence of pile diameter and spacing variations on the bearing capacity of pile foundations at the Dumping 2 area of the Dermaga Curah Cair Benoa Bali. Secondary N-SPT data from five borehole points, namely BH-D-07, BH-R-02, BH-R-03, BH-R-04, and BH-R-05, each with a depth of 30 m, were used in this study. The single pile bearing capacity was calculated using the Meyerhof Method (1956) and the Luciano Decourt Method (1982) with pile diameter variations of 0.4 m, 0.5 m, 0.6 m, and 0.8 m, while the group pile bearing capacity was calculated using the Converse- Labarre Method with pile spacing variations of 2.5D and 3D. The results show that the Meyerhof method produces higher bearing capacity values than the Luciano Decourt method at all borehole points, so the allowable bearing capacity from the Luciano Decourt method was selected as the basis for group pile calculation due to its more conservative results. Increasing the pile diameter from 0.4 m to 0.5 m, 0.5 m to 0.6 m, and 0.6 m to 0.8 m resulted in average increases in group bearing capacity of 35.07%, 27.78%, and 54.40%, respectively. Meanwhile, increasing the pile spacing from 2.5D to 3D resulted in an increase in group bearing capacity of 4.93% to 6.08%, due to the improvement in group pile efficiency. The BH-R-02 borehole produced the highest bearing capacity due to the presence of a hard soil layer in the form of bouldering sand with an N-SPT value reaching 61, while the BH-D-07 borehole produced the lowest bearing capacity due to the dominance of soft soil with low N-SPT values.