Kemudian dilakukanlah perhitungan daya dukung pondasi dengan metode Meyerhof (1976), Skempton (1966), dan Reese & O'neill (1999) pada kondisi tanah Undrained. Penurunan tiang tunggal dengan metode Vesic (1977) dan Poulos & Davis (1980) serta menggunakan program Plaxis 2D selanjutnya analisa tiang grub mengunakan metode Vecic (1977) dan program plaxis 2D di ketiga model yang sedang di teliti. Selanjutnya dari hasil perhitungan dibandingkan antara podasi boredpile dengan tiang pancang model 1 dan 2. ......A foundation is a part of an engineering system that works by transmitting the load it supports and its own weight into the soil or rock beneath it. Choosing the type of foundation is very important in the building structure, to be able to withstand the load of the building as well as the live load within the building as well as the planned earthquake load so that structural collapse does not occur. The building of the Rokan Hilir Regency regent's office, which was completed in 2011 and there was a decline in the building, is the subject of my research. Based on the results of field and laboratory soil tests for the building, the hard soil obtained was >36 meters, and a bored pile foundation was chosen as the building foundation with a depth of 38 meters with a diameter of 0.8 meters. In this research, the author plans to compare the bored pile foundation that has been applied to the building with other alternative foundations, namely pile foundation 1 with a depth of 38 meters with a diameter of 0.8 meters, and pile 2 with a depth of 38 meters with a diameter of 1 meter in terms of bearing capacity. and the magnitude of the decline. To carry out the analysis, the data used are technical drawings (Data as build drawing), Standard Penetration Test (SPT) data and Sondir test. The amount of building load distributed to the ground is obtained from the results of calculations carried out by planning consultants.
Then the foundation bearing capacity was calculated using the Meyerhof (1976), Skempton (1966), and Reese & O'neill (1999) methods in undrained soil conditions. Derivation of a single pole using the Vesic (1977) and Poulos & Davis (1980) methods and using the Plaxis 2D program, then analyzing the grub pole using the Vecic (1977) method and the Plaxis 2D program in the three models being studied. Furthermore, the calculation results are compared between the boredpile foundation and pile models 1 and 2.