The Impact of Using Different Types of Soft Soils Treated by Stone Columns on Creep Behavior

The stone column technique is an effective method to increase the strength of soft cohesive soil, which results in a reduction in foundation settlement and an increase in bearing capacity. The topic of restraining creep settlement through the use of stone columns techniques has gained increasing attention and consideration; because stone columns are widely used to treat soft soil deposits, caution should be applied in estimating creep settlement. We discovered a reversible relation between shear parameters and the creep settlement in floating stone columns; while, in case of end-bearing stone columns shows a direct positive relation between shear parameters and the creep settlement, and the creep settlement began at the primary settlement. The shear parameters affected the improvement factor (n) of creep settlement in both floating and end-bearing stone columns. The standard creep coefficient’s n values in floating and end-bearing conditions were more significant than the low creep coefficient’s n values in forwarded geometric conditions. The stress in both floating and end-bearing stone columns was increasing and uniformly distributed along the length of the floating stone column and in the case of end-bearing stone column was limited to the stiffness layer; the maximum vertical stress was in the central point of the embankment. The embankment’s maximum horizontal displacement occurred on the edge.

Statistical Analysis on the Static Characteristics of the Geosynthetic Encased Stone Column

The geosynthetic encased stone column is made of stone column encased with geosynthetic encasement. The geosynthetic encased stone column is often used for foundation treatment of roadbeds, dams, buildings and other structures. At present, a series of new developments have been made in the researches of bearing capacity, stress concentration ratio and deformation of the geosynthetic encased stone column. This paper statistically analyzes the three important static characteristics of the geosynthetic encased stone column.

Experimental and numerical study of the behavior of a stone column subject to the loading effect

The realization of engineering structures in compressible sites, requires in-depth geotechnical reconnaissance, as well as a study of the mechanical behavior of the soil, in order to adapt suitable soil improvement solutions. This is the case with the Annaba viaduct in Algeria, where it was found during the site survey that the soil is poor and very compressible. The foundations in these soils eventually pose the problem of their low bearing capacity and significant settlement. This, therefore, leads to the choice of reinforcement techniques. Among the many methods of improving soils, we have selected the stone column technique. The object of our article is to study the behavior of these columns, in terms of settlement and, through the loading tests on real site, we have found out that the intermediate columns are stiffer and more confined than the bank columns and the percentage reduction in settlements of these two types is important. Then, this experimental study is validated by the Plaxis 2D software, where the configurations are studied to find the best model that approximates the real behavior of the reinforced soil.

Stabilization of Kaolin Clay Soil Reinforced with Single Encapsulated 20mm Diameter Bottom Ash Column

Ground improvement methods are used to reduce the weakness of soft clay, which is low strength and high compressibility. The stone column technique involves replacing any of the soil with crushed stone such as broken rocks or sand which is an efficient method of improving the strength parameters of soil. Bottom ash usage in materials of building will effectively decrease the buildup of the waste and hence protect the environment. This study is to determine the shear strength of kaolin soft clay reinforced with a 20 mm diameter single encapsulated bottom ash column with various lengths. The research will look into the physicomechanical qualities of the materials used, including subsoil and bottom ash. Three (3) batches of samples with each batch consists of five (5) samples were prepared by using compaction method. All kaolin samples with a diameter of 50mm and height of 100mm with single encapsulated bottom ash columns with various lengths which are 60mm, 80mm, and 100mm were tested under Unconfined Compression Test (UCT). The result illustrated that the strength of samples increases as the height and volume of encapsulated bottom ash column increases.

Comparative Study of Existing Cement Fly Ash Gravel pile and Encased Stone Column Composite Foundation

The Cement Fly Ash and Gravel (CFG) Pile and Encased Stone Column (ESC) are the ground improvement techniques. The main object of the study is to the numerical analysis of the Both techniques pile group were used to support the Embankment with and without the geotextile both techniques composite foundation by the Finite Element method under static and dynamic load analysis. Numerical simulation has been carried out in Plaxis 3D. A case study from china’s highspeed embankment supported by CFG and ESC have investigated the load caring capacity by soil and pile. While the failure behaviors, settlement, excess pore pressure, and lateral behavior with variable embankment loading and number of geosynthetic effect moreover, the diameter of CFG piles and ESC at various locations in an embankment has been varied to study its influence on the load distribution among the CFG piles/ESC and lateral load displacement of the pile group. The results show that increasing the diameter of both techniques reduced the total settlement and differential settlement of embankment. It observed that the seismic load has a significant effect on the vertical and lateral displacement.