Numerical Analysis of Soil Improvement for a Foundation of a Factory Using Stone Columns Made of Different Types of Coarse-grained Materials

Abstract

Stone columns made of coarse-grained materials and crushed stone are one of the most-used technologies for soil improvement all over the world. Stone columns improve the strength and deformation properties of subsoil and reduce the time required for the consolidation of fine-grained soils. The impact of the improvement depends on the properties of the original subsoil as well as the properties of the coarse-grained materials used for the stone columns. The article deals with the effects of the properties of coarse-grained materials for stone columns on the settlement and consolidation times of improved subsoil for the foundation of a factory. Numerical modeling as a 2D task was performed using Plaxis geotechnical software. The numerical analysis included two methods of modeling stone columns in a plane strain model, i.e., one method often used by practical engineers in the region of Slovakia, and one modified method, which allowed for a more accurate determination of the final settlement and consolidation time. The method modeled stone columns as continuous walls, and the compaction of the soil between the stone columns was taken into account. The results showed that the type of coarse-grained material can significantly affect the final settlement and time of consolidation. Stone columns made of quarry stone were suitable in the given geological conditions regardless of the design of the mesh, while stone columns made of pebble gravel were suitable only with a mesh of 1.5 x 1.5 m.

Design and Modelling Process of Soil Improvement with Concrete Strengthening Elements

“…The reaction forces are not only absorbed by the concrete reinforcing elements, but also a significant proportion transferred to the subsoil due to the plate-like behavior of the bedding layer. [4]…”

“…The relationship between the internal friction angle of the load transfer platform and the efficiency factor [5] Fig. 4 Effect of the ratio of the bedding layer and the grid spacing on the efficiency factor [5] 4 Finite element modelling of the system The detailed structural behavior of the foundation system was analyzed with Plaxis 3D geotechnical finite element software, which provides an opportunity to analyze soil-structure interaction. Due to the complexity of subsoil strengthening with this method 2D plane strain modelling is only possible with a lot of geometrical simplifications, which thus does not work properly results for a complete analysis of the structural elements.…”

Laboratory Investigation on the Effect of Microsilica Additive on the Mechanical Behavior of Deep Soil Mixing Columns in Saline Dry Sand

“…Among deep improvement methods, the DSM method with different slurry and additive like cement, microsilica, fly ash, lime and etc. has received much attention from geotechnics and geology researchers [14][15][16][17][18][19][20][21][22][23]. For instance, the effect of salt in loose soil was studied on soil improvement adopting deep soil mixing method with cement slurry.…”