ABSTRAK
Setiap bangunan memerlukan pondasi sebagai dasar bangunan yang kuat dan kokoh, karena pondasi sebagai dasar bangunan harus mampu memikul seluruh beban bangunan dan beban lainnya untuk diteruskan sampai kelapisan tanah di bawahnya. Kemampuan pondasi memikul beban tersebut disebut daya dukung pondasi.Besarnya daya dukung dan penurunan pondasi dapat diketahui dengan analisis metode empiris, pemodelan metode elemen hingga dan uji beban statis (loading test). Pondasi dalam (deep foundation) secara umum memiliki permasalahan yang lebih rumit daripada pondasi dangkal (shallow foundation). Karena adanya parameter-parameter tanah yang sangat perlu diperhatikan dalam menganalisis besar daya dukung pondasi dalam.
Tesis ini menganalisis kapasitas daya dukung dan penurunan (settlement) pada pondasi tiang bored pile diameter 600 mm secara tiang tunggal maupun kelompok tiang, dengan metode empiris, program AllPile, program Plaxis, program SAP2000 dan membandingan hasilnya dengan interpretasi uji beban statis (loading test) pada pondasi proyek Medan Focal Point. Analisis menggunakan data penyelidikan tanah lapangan (soil investigation) dan laboratorium serta membandingkan terhadap model tanah Mohr Coulomb.
Hasil analisis daya dukung ultimate pondasi bored pile dengan metode empiris memberikan nilai terbesar yaitu dengan mempergunakan data N-SPT yaitu 697,83 ton dengan metode Reese and Wright serta nilai terkecil 387,67 ton dengan metode Touma and Reese, serta sebesar 26,60 ton untuk daya dukung lateral ultimate, 13,30 ton untuk daya dukung lateral yang diizinkan. Dimana hasil daya dukung lateral ultimate dari program SAP2000 adalah 25,20 ton. Hasil loading test diperoleh daya dukung ultimate 300,00 ton. Maka berdasarkan hasil daya dukung pondasi tersebut aman. Penurunan yang terjadi hasil analisis pemodelan elemen hingga hingga dengan program Plaxis adalah 5,462 mm, hasil program AllPile adalah 9,99 mm, dan hasil loading test di lapangan penurunan pada beban terbesar yang terjadi sebesar 5,443 mm. Berdasarkan ASTM D1143/81, penurunan yang diizinkan adalah sebesar 25,40 mm. Maka berdasarkan penurunan bahwa tiang pondasi aman dalam konstruksi.
ABSTRACT
Every construction needs foundation as a strong construction basis because foundation must be capable of carrying the whole building load and other loads for planting into the ground under it. The capacity of foundation to carry the load is called foundation supporting capacity. The amount of supporting capacity and foundation settlement can be known by conducting empirical method, element modeling, and loading test. Deep foundation generally has more complex problems than shallow foundation. Therefore, the parameters of soil need to be heeded in analyzing supporting capacity of deep foundation.
This Thesis analyzed supporting capacity and settlement in bored pile foundation of 600 mm in diameter, using single of group piles, empirical method, All Pile program, Plaxis program, and SAP2000 program, and compared the result with the interpretation of loading test in the project foundation of Medan Focal Point. The data were analyzed by conducting soil investigation and laboratory and compared them with Mohr Coulomb soil model.
The result of the analysis on the ultimate supporting capacity of bored pile foundation, using empirical method, showed that the highest value in N-SPT data was 697.83 tons by using Reese and Wright method and lowest value was 387.67 tons by using Touma and Reese method, 26.60 tons for ultimate lateral supporting capacity, 13.30 tons for permitted lateral supporting capacity, in which the result of ultimate lateral supporting capacity of SAP2000 was 25.20 tons. The result of loading test showed that ultimate supporting capacity was 300 tons which indicated that the supporting capacity of the foundation was safe. The settlement of the result of finite element modeling analysis with Plaxis program was 5.462 tons, the result of All Pile program was 9.99 mm, and the result of loading test in the field showed that the biggest load settlement was 5.443 mm. Based on ASTM D1143/81, it was found that the permitted settlement was 25.40 mm which indicated that bored pile foundation was safe in construction.
