Studi Analisis Daya Dukung Aksial Fondasi Tiang Berdasarkan Kurva Load-Settlement Hasil Static Loading Test (SLT) dan TZPILE
Abstrak
Abstract
One of the methods has been used to identify the behavior of pile foundation while receiving axial load is t-z method. By using T-z method, the behavior of pile foundation while transferring the axial load (load transfer, t) and settlement (z) which is called load-settlement curve could be quantified. In this research, driven pile is used with the soil is predominantly clay. TZPILE is employed to generate load-settlement curve. That load-settlement curve which were generated by TZPILE is then compared with that of Static Loading Test (SLT). According to that comparison, a load-settlement curve has been predicted (predicted SLT) if downdrag condition is applied. On the other hand, the methods of Davisson (1972), Van Der Veen (1953), andMazurkiewicz (1972) are utilized to calculate ultimate bearing capacity (Qult) and allowable bearing capacity (Qall) by interpreting the data of SLT and predicted SLT. Thereafter,evaluation of working load has been carried out by considering the settlement of load-settlement curve. The results of TZPILE show that the load-settlement curve is well predicted so then it can be adopted to predict load-settlement curve of SLT in downdragcondition. Three methods of interpreting of SLT and predicted SLT show that Qall are greater than working load, otherwise predicted SLT. Evaluations of Qall by considering the settlement show that Qall is greater than the results of Davisson (1972), Van Der Veen (1953), and Mazurkiewicz (1972). Surprisingly, all the results show that Qall is greater than working load.
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Keywords: pile foundation, t-z curve, stating loading test
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Abstrak
Salah satu metode yang digunakan untuk mengetahui perilaku fondasi tiang dalam menerima beban aksial (axial load) adalah t-z method atau metode t-z. Melalui metode t-z didapatkan perilaku fondasi dalam penyaluran beban aksial (load transfer, t) dan displacement (z) yang terjadi atau dikenal sebagai kurva load-settlement. Pada penelitian ini digunakan tiang pancang (driven pile) dengan data tanah yang didominasi oleh lempung. Pemodelan menggunakan program bantu TZPILE dilakukan untuk mendapatkan kurva load-settlement. Kemudian dilakukan perbandingan kurva load-settlement dari TZPILE dan Static Loading Test (SLT). Hasil perbandingan tersebut digunakan untuk memprediksi kurva load-settlement SLT (SLT prediksi) jika pada kondisi downdrag. Perhitungan daya dukung ultimit (Qult) dan daya dukung ijin (Qall) dilakukan dengan menginterpretasi data SLT dan SLT prediksi menggunakan 3 (tiga) metode yang berbeda yaitu metode Davisson (1972), Van Der Veen (1953), dan Mazurkiewicz (1972). Evaluasi working load dilakukan dengan mempertimbangkan penurunan pada kurva load-settlement. Hasil pemodelan menunjukkan bahwa TZPILE bias memprediksi kurva load-setllement dengan baik sehingga bias digunakan untuk memprediksi kurva load-setllement hasil SLT jika terdapat pengaruh downdrag. Hasil interpretasi kurva load-settlement dari SLT dan SLT prediksi dengan ketiga metode menunjukkan nilai Qall diatas working load, kecuali untuk SLT prediksi. Evaluasi Qall dengan mempertimbangkan penurunan menghasilkan nilai Qall yang lebih besar dari hasil interpretasi dengan ketiga metode. Bahkan semuanya menunjukkan Qall yang lebih besar dari working load.
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Kata Kunci: fondasi tiang, kurva t-z, static loading test
Artikel teks lengkap
Referensi
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Penulis
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