Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2019
Student: GÖZDE TAŞKINÖZ
Supervisor: MEHMET KABAK
Abstract:Rigid inclusions such as jet-grouting, deep soil mixing, and concrete columns are the ground improvement techniques used to reduce the settlement and/or increase the bearing capacity. Reinforcement is generally not used in rigid columns. It is also distinguished from deep foundations by the granular layer placed between the foundation and the column heads. In this system, the granular layer (load transfer platform) transfers the loads from the superstructure to the upper-end region of the column. Within the scope of this study, the load-deformation graph of the pile, which is 80 cm in diameter and 20 meters in length, was used to calibrate the soil parameters in MIDAS GTS which is a finite element program and used in this study. The soil profile of the land is idealized as 3 layers depending on the SPT-N values and laboratory test results. In the three-dimensional analysis model, the column was modeled as a completely solid structural element. The interface element was used to allow relative movement between the column and the ground. The non-linear analyses were made by defining a granular layer having different thicknesses and modulus of elasticity between the 4-column group and the foundation. As a result, it was seen that rigid inclusion systems were as effective as pile foundation systems in overcoming settlement and bearing capacity problems of soft soil. However, the amount of settlement calculated at the top of the concrete column using the load transfer platform was less than the pile connected to the raft foundation. By increasing the load-transfer platform thickness, it was seen that the settlement of the columns decreased, and the total settlement of the system increased. Increasing the load-transfer platform thickness caused a reduction of the shear stresses in it. Moreover, increasing the elasticity modulus and internal friction angle (Φ') of the load-transfer platform increased the amount of load transferred to the column heads while reducing the total settlement of the system