i ABSTRAK
Dalam perencanaan suatu bangunan, perlu dilakukan analisis yang benar mengenai kapasitas bangunan dalam memikul beban-beban yang ada. Salah satu komponen bangunan yang memerlukan penelitian yang komprehensif adalah pondasi atau struktur bawah dari bangunan karena pondasi dan struktur bawah tersebut memikul beban dari struktur atas dan mentransfer beban tersebut ke tanah di bawahnya.
Tesis ini menganalisis kapasitas daya dukung dan penurunan pada pondasi tiang tekan hidrolis jenis Prestressed Concrete Square Pile ukuran 45 cm × 45 cm dalam bentuk tiang tunggal maupun kelompok tiang. Metode yang dipergunakan antara lain metode empiris, Program Finite Element Method, Program AllPile, dan membandingkan hasilnya dengan interpretasi uji beban statis aksial (Loading Test) pada Tribeca Condominium Northern Proyek Podomoro City Deli Medan. Analisis menggunakan data penyelidikan tanah (Soil Investigation) dan laboratorium serta menggunakan metode elemen hingga dengan pemodelan tanah Mohr Coulomb dan Soft Soil.
Hasil analisis daya dukung Ultimate pondasi tiang tekan hidrolis dengan metode empiris memberikan nilai terbesar pada analisis yang mempergunakan data parameter tanah yaitu 690,86 ton dengan Metode Meyerhoff, sedangkan nilai terkecil diperoleh dari analisis menggunakan Finite Element Method yaitu 286,91 ton. Daya dukung yang diminta oleh Perencana Strukturnya sebesar 150 ton belum dapat dipenuhi oleh hasil daya dukung dari data FEM karena daya dukungnya (286,91)/2 = 143,46 ton (lebih kecil dari 150 ton). Hal yang sama juga terjadi pada hasil interpretasi Loading Test yaitu dari metode Davisson (146,00 ton) dan Chin (134,71 ton), belum ada yang memenuhi syarat memikul beban kerja 150 ton. Daya dukung lateral tiang diperoleh sebesar 12,15 ton dari Metode Broms dan 33,02 ton dari Finite
Element Method. Daya dukung lateral tiang yang diambil adalah sebesar 12,15 ton
karena merupakan kekuatan bahan tiang terhadap beban lateral. Sedangkan untuk daya dukung kelompok tiang (525 titik dalam satu pilecap) diperoleh efisiensi terkecil 0,66 dari Converse-Labarre Equation dan efisiensi terbesar 0,71 dari Los Angeles Group Action Equation.
ii
penurunan daripada spun pile dengan asumsi mutu beton dan luas penampang yang sama. Dan pemodelan tanah Mohr-Coulomb untuk tanah dominan pasir dan Soft Soil untuk tanah dominan lempung memberikan hasil analisis beban – penurunan yang mendekati hasil beban – penurunan dari Loading Test.
iii ABSTRACT
In planning to construct a building, it is necessary to conduct correct analysis on its capaCity in carrying the loads. One of the building components which need a comprehensive study is foundation or lower structure of the building since foundation and lower structure carry the load of the higher structure and transfers it to the soil under it.
This thesis analyzed the capaCity of carrying capaCity (portative power) and the settlement of hydraulic stressed pile foundation of Prestressed Concrete Square Pile of 45 cm
×
45 cm in cross section in single pile or group pile. The research used empirical method, finite element method program, and Allpile program, and compared the result with the interpretation of axial static loading test (Loading test) at Tribeca Condominium Northern, Podomoro Project of City Deli, Medan. The analysis used soil investigation, laboratory study, and finite element by Mohr Coulumb soil and soft soil models.The result of the analysis on the ultimate carrying capaCity of hydraulic stressed pile foundation with empirical method gave the highest value in the analysis which used soil parameter data of 690.86 tons with Meyerhoff method, while the lowest value from the analysis, using Finite Element method, it was 286.91 tons. Carrying capaCity asked by the structural planner for 150 tons could not be carried by the result of carrying capaCity from FEM data because its carrying capaCity was (286.91)/2 = 143.46 tons (less than 150 tons). The same was true to the result of the interpretation of Loading Test with Davisson method (146 tons) and with Chin (134.71 tons) so that there was no one of them had met the requirement for carrying the work loads of 150 tons. Carrying capaCity of lateral pile was 12.15 tons with Broms method and 33.02 tons with Finite Element method. Carrying capaCity of lateral pile was 12.15 tons because it was pile material strength on lateral pile, while the carrying capaCity of group pile (525 points in one pile cap) indicated the lowest efficiency of 0.66 from Converse-Labarre Equation and the highest efficiency was 0.71 from Los Angeles Group Action Equation.
For 200% of planning load of 150 tons, that is, 300 tons, the settlement of single pile which occurred from the result of the analysis on Finite Element method program was 3.65 mm, from Allpile program was 7.52 mm, from Loading Test was 4.62 mm, and from empirical method (Vesic Method) was 1.52 mm. The result of the analysis on the settlement of group pile with Vesic method, the settlement was 1.38 cm while from Allpile program it was 0.43 cm. The result of the analysis on the settlement of group pile with Allpile program was more reliable because it has inserted soil layers and its soil parameter. It was also found that square pile was better from its strength, carrying capaCity, and the settlement of spun pile with the assumption of concrete quality and the same section area. Mohr-Coulumb soil modeling for dominantly sandy soil and soft soil for dominant loam gave the result of load analysis – the settlement which was close to load result – the settlement of Loading Test.
