Numerical analysis of the jet grout soil reinforcement by finite element method

Today, the rapid increase in population, industrialization and distribution of new urban centers, as observed in almost all developing countries, causes a rapid depletion of settlement areas as well in Turkey. The new settlement areas to be opened in the growing and developing cities are gradually getting smaller. As a natural consequence of increased settlement needs, it has become compulsory to construct engineering works on unsuitable soils besides for places where building-foundation ground characteristics are suitable for a possible construction. In this sense, it has become widespread to work on ground improvement work against the bearing capacity, high deformation and settlement problems encountered on the weak soils or improving the soil properties. The most basic solution is to design a building based on existing soil. If this case is not possible; the weaker ground can be removed and replaced with a more robust ground or the weaker ground can be transported to the deeply grounded buildings on the lower ground. When both two cases are not possible; the ground properties can be improved by the ground improvement methods. Jet-grouting columns, one of the soil improvement methods in the literature, is a high-strength columns consisting of a mixture of cement and soil, and the soil is compressed and become consolidated during production. In this context, scientific studies have been also used to mitigate soil liquefaction problems, which cause building foundations to be affected by seismic movements. In this thesis, the behaviour of the soil in the case of jet-grouting soil improvement method in a liquafable problematic soil is modelled using the finite element method for both static and dynamic case. Numerical analyses are correlated bith the data obtained from field and laboratory experiments and the study area is evaluated under different scenarios. Within the scope of work; Jet grouting method is also assessed in dfifferent aspects such as a design method, design criteria and settlement mechanism. By comparing the geotechnical parameters obtained prior and post soil improvement, it was determined that the displacement values were decreased following the improvement in the study area. The results also prove that, the numerical analysis conducted prior to the project implementation on the ground can provide economic benefits.