ANALISIS DAYA DUKUNG PONDASI TIANG BORE PILE DENGAN METODE MEYERHOF DAN HILEY: STUDI KASUS JEMBATAN MORO’O

Abstrak

Pondasi tiang bor merupakan salah satu jenis pondasi dalam yang sering digunakan untuk konstruksi gedung dan jembatan berskala besar. Analisis daya dukung dan penurunan pondasi perlu dilakukan untuk memastikan pondasi mampu menahan beban di atasnya. Penelitian ini menganalisis kapasitas dukung pondasi tiang bor diameter 80 cm dan panjang 12 m pada Jembatan Moro’o (bagian dari Proyek Jalan dan Jembatan Sirombu–Afulu) dengan menggunakan metode dinamis (Pile Dynamic Load Test/PDA) dan membandingkannya dengan perhitungan teoritis metode Meyerhof (statis) dan metode Hiley (dinamis). Data uji PDA di lapangan diperoleh dengan menjatuhkan hammer seberat 4 ton pada tiang uji dan merekam responnya menggunakan Pile Driving Analyzer. Hasil analisis numerik berupa nilai daya dukung ultimit dan penurunan dibandingkan dengan hasil uji PDA serta (rencana) uji beban statis di lokasi proyek. Kondisi tanah di lokasi berupa tanah pasir, dan pondasi yang digunakan adalah tiang bor berdimensi Ø80 cm dengan panjang 12 m. Metode Meyerhof dan Hiley digunakan untuk menghitung kapasitas dukung ultimit berdasarkan data sondir dan data pemancangan. Uji PDA bertujuan mengevaluasi daya dukung aksial tiang, integritas struktur tiang, serta besarnya energi tumbukan yang ditransfer. Hasil penelitian menunjukkan bahwa kapasitas dukung ultimit tiang bored pile Ø80 cm (L=12 m) yang diperoleh dari uji PDA mencapai sekitar 155,2 ton, dengan komponen gesekan dominan sekitar 135,0 ton dan tahanan ujung 20,2 ton. Uji integritas (PIT) pada dua tiang menunjukkan tiang dalam kondisi baik, dengan nilai Bored Pile Toe Assessment (BTA) masing-masing 61,01% dan 52,05%, di mana grafik gelombang kecepatan menunjukkan perubahan signifikan pada segmen atas tiang (±5–7 m dari kepala tiang) yang mengindikasikan adanya friksi tanah atau perubahan penampang. Refleksi gelombang pada ujung tiang terdeteksi jelas di kedalaman 12 m, menandakan tiang mencapai lapisan keras sesuai rencana.

Bored pile foundations are one type of deep foundation that is often used for large-scale building and bridge construction. Analysis of the bearing capacity and settlement of the foundation is necessary to ensure that the foundation can withstand the load above it. This study analyzes the bearing capacity of 80 cm diameter and 12 m long bored pile foundations on the Moro'o Bridge (part of the Sirombu–Afulu Road and Bridge Project) using the dynamic method (Pile Dynamic Load Test/PDA) and compares it with theoretical calculations using the Meyerhof (static) and Hiley (dynamic) methods. PDA test data in the field was obtained by dropping a 4-ton hammer on the test pile and recording the response using a Pile Driving Analyzer. The results of the numerical analysis in the form of ultimate bearing capacity and settlement values were compared with the PDA test results and the (planned) static load test at the project site. The soil conditions at the site were sandy, and the foundation used was a bored pile with dimensions of Ø80 cm and a length of 12 m. The Meyerhof and Hiley methods were used to calculate the ultimate bearing capacity based on sounding data and pile driving data. The PDA test aimed to evaluate the axial bearing capacity of the pile, the structural integrity of the pile, and the amount of impact energy transferred. The results of the study show that the ultimate bearing capacity of the Ø80 cm bored pile (L=12 m) obtained from the PDA test reached approximately 155.2 tons, with a dominant friction component of approximately 135.0 tons and an end resistance of 20.2 tons. Integrity tests (PIT) on two piles showed that the piles were in good condition, with Bored Pile Toe Assessment (BTA) values of 61.01% and 52.05%, respectively, where the velocity waveform graph showed significant changes in the upper segment of the pile (±5–7 m from the pile head), indicating soil friction or cross-sectional changes. Wave reflections at the pile tip were clearly detected at a depth of 12 m, indicating that the piles reached the hard layer as planned.