REDESIGN PONDASI GABUNGAN FOOTPLAT DAN BORED PILE PADA BANGUNAN HUNIAN BERTINGKAT (Studi Kasus : Desa Meteseh, Kelurahan Boja, Kabupaten Kendal)

ABSTRAK

Pondasi berfungsi mendistribusikan beban struktur atas ke lapisan tanah. Kesalahan perancangan pondasi dapat mengakibatkan kegagalan struktur atau membengkaknya anggaran proyek. Oleh karena itu, penelitian ini bertujuan untuk
mengetahui desain dan dimensi pondasi yang optimal berdasarkan perhitungan kapasitas daya dukung, penurunan (settlement) secara perhitungan manual dan software Allpile. Perbandingan rencana anggaran biaya (RAB) pada pondasi gabungan eksisting dengan pondasi gabungan redesign. Metode penelitian menggunakan data geoteknik dari Cone Penetration Test (CPT) dan direct shear test laboratorium, analisis pembebanan struktur menggunakan SAP2000, serta analisis pondasi untuk penurunan menggunakan software Allpile dan efisiensi tulangan dengan spColumn. Hasil analisis redesign pondasi gabungan diperoleh
hasil kapasitas daya dukung gabungan (Qtotal) FP1 sebesar 6190,054 kN, FP2 sebesar 528,701 kN dari hasil tersebut dinyatakan aman terhadap beban aksial. Penurunan redesign pondasi dilakukan dengan perhitungan manual tiang kelompok
(Sg) FP1 sebesar 0,0006404 cm, FP2 sebesar 0,0004816 cm dan software Allpile pada FP1, FP2 sebesar 0,000001 cm. Pondasi FP1 menggunakan penampang footplat berdimensi 1,2 x 1,2 meter, tinggi tapak footplat 0,4 meter, kedalaman 2 meter, dan 2 tiang bored pile menggunakan diameter 0,2 meter, sedangkan FP2
menggunakan penampang footplat berdimensi 0,7 x 0,7 meter, tinggi tapak footplat 0,35 meter, kedalaman 1,4 meter dan 1 tiang bored pile menggunakan diameter 0,2 meter kedalam 4 meter.Perbandingan hasil rencana anggaran biaya antara pondasi
gabungan eksisting dengan pondasi gabungan redesign pada FP1 didapatkan penghematan anggaran sebesar Rp. 23.029.434,37 sedangkan FP2 didapatkan penghematan anggaran sebesar Rp. 6.070.224,42.

Kata kunci: pondasi gabungan; footplate; bored pile; daya dukung; penurunan

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ABSTRACT

Foundations distribute the load of the superstructure to the soil layers. Errors in foundation design can lead to structural failure or a bloated project budget. Therefore, this research aims to determine the optimal foundation design and dimensions based on bearing capacity and settlement calculations, both manually and with Allpile software. This study compares the bill of quantities (BOQ) of the existing combined foundation with the redesigned combined foundation. The research method uses geotechnical data from a Cone Penetration Test (CPT) and
a direct shear laboratory test. Structural load analysis is performed using SAP2000, while foundation analysis for settlement is conducted with Allpile software and reinforcement efficiency is determined with spColumn. The analysis results for the redesigned combined foundation show a combined bearing capacity (Qtotal) of 6190.054 kN for FP1 and 528.701 kN for FP2. These results indicate that the foundations are safe against axial loads. The settlement of the redesigned
foundations was calculated manually for the pile group (Sg), resulting in 0.0006404 cm for FP1 and 0.0004816 cm for FP2. The Allpile software calculation for settlement yielded 0.000001 cm for both FP1 and FP2. The FP1 foundation uses a footing with dimensions of 1.2 x 1.2 meters, a footing height of 0.4 meters, a depth of 2 meters, and two bored piles with a diameter of 0.2 meters. The FP2 foundation uses a footing with dimensions of 0.7 x 0.7 meters, a footing height of 0.35 meters, a depth of 1.4 meters, and one bored pile with a diameter of 0.2 meters to a depth of 4 meters. A comparison of the bill of quantities between the existing combined foundation and the redesigned combined foundation for FP1 shows a budget saving of Rp. 23,029,434.37, while FP2 shows a budget saving of Rp. 6,070,224.42.

Keywords: combined foundation; footplate; bored pile; bearing capacity; settlement