The effect of stone column geometry on soft soil bearing capacity

2019 ◽  
pp. 1-11 ◽  
Author(s):  
Alarifi Hamzh ◽  
Hisham Mohamad ◽  
Mohd Fairus Bin Yusof
Keyword(s):  
Bearing Capacity ◽  
Soft Soil ◽  
Stone Column

scholarly journals Behavior of Stone Column improved Clay soil under static loading-A numerical exploration

2020 ◽  
Vol 9 (9) ◽  
pp. 440-445
Keyword(s):  
Bearing Capacity ◽  
Soil Stabilization ◽  
Clay Soil ◽  
Soft Soil ◽  
Soft Clay ◽  
Cost Effective ◽  
Element Model ◽  
Vital Role ◽  
Stone Column ◽  
Cost Effective Method

Problematic soil which cause extra problems from engineering point of views which result in its composition or environmental conditions change. The weak subsoil deposits like soft clay pose the low bearing capacity and more settlements over long periods of time. The stone column technique is better, economical and cost-effective method of soft soil stabilization. They are used to support embankments, large raft foundations and isolated footings. Numerous researchers have just completed various vertical stacking probes stone column balanced out clay bed and have discovered that expands bearing capacity of delicate clay, diminishes displacement and changes the conduct of burden settlement. In the current study, a 2D finite element model is completed to evalute how the delicate clay soil balanced out by stone column are affected by the vertical burdens. Stone column were intended for examinations with fluctuating in their angle proportions (change in estimations of length, L and breadth, D) of stone column. The effect of floating stone column and end bearing stone segment on delicate clay is in like manner controlled by using various L/D ratios. Besides, the present outcomes express how the heap conveying limit of stone column is differed by changing in the angle proportions of the stone column. Likewise ends were drawn that bulging impact of stone column plays a vital role in conveying vertical burden.

scholarly journals Evaluation Of Use of Stone Column in Unengineered Closed Landfill Soil

2021 ◽  
Vol 23 (08) ◽  
pp. 538-548
Author(s):  
Mandeep Singh ◽  
◽  
Dr Prashant Garg ◽  
Keyword(s):  
Bearing Capacity ◽  
Load Capacity ◽  
Ground Improvement ◽  
Soft Soil ◽  
Confining Pressure ◽  
Lateral Spreading ◽  
Silty Sand ◽  
Stone Columns ◽  
Stone Column ◽  
Closed Landfill

In the building industry, ground improvement techniques based on stone column are widely employed. It is a very successful approach for enhancing the engineering characteristics of soil in all aspects, as well as reducing the settling issue in poor-grounded soils including silt, clay, silty sand, and organic soil. The performance of stone columns, is determined by the confining pressure provided by the surrounding soils. Engineering constructions built on thick layers of soft soil strata face issues such as limited bearing capacity, excessive total and differential settlement, lateral spreading, and so on. To address such issues, many ground improvement techniques are available. In exceptionally soft soils, the lateral confining pressure may be inadequate, resulting in column bulging failure. Individual stone column encasement improves lateral resistance to bulging by adding restricting pressure. This research focuses on the geotechnical aspects of building on closed landfill sites. A total of 33 models were tested in a geotechnical engineering laboratory on virgin former landfill soil and stone column with and without encasement in this current study. The increased diameter, length and L/D ratio of the column has demonstrated that the load capacity has increased and soil settling has decreased. When an unreinforced stone column has been installed, the ultimate bearing capacity of landfill soil is increased by 75-112.50 per cent and 87.50-176 per cent respectively, for 10mm and 20mm diameter stone column. Furthermore, when a fully reinforced stone column has been installed, it had increased by 156.25-212.50 per cent and 200-298 per cent for 10mm and 20mm diameters respectively. The stiffness of soil is increased by the stone column, which contributes to increase in the load capacity. The geogrid layer confines an aggregate, which contribute to enhance shear stiffness and bearing capacity.

scholarly journals Improvement of Soft Soil Using Linear Distributed Floating Stone Columns under Foundation Subjected to Static and Cyclic Loading

2019 ◽  
Vol 5 (3) ◽  
pp. 702 ◽  
Author(s):  
Mahdi O Karkush ◽  
Anwar Jabbar
Keyword(s):  
Cyclic Loading ◽  
Bearing Capacity ◽  
Soft Soil ◽  
Friction Angle ◽  
Soil Improvement ◽  
Stone Columns ◽  
Stone Column ◽  
Column Material ◽  
Area Replacement Ratio ◽  
Static And Cyclic Loading

A stone column is one of the soil improvement methods that are mainly used for improving the geotechnical behavior of soft soils. For deep improvement of soft soil, the floating stone columns are considered the best and effective economically which provide lateral confinement and drainage and longitudinal skin friction. In this study, six tests were carried out on the natural soft soil of undrained shear strength of 5.5 kPa improved by single and two linear distributed floating stone columns. The stone column dimensions are 30 mm in diameter and 180 mm in length and the stone column material is sand of high internal friction angle of 48°. The natural and improved soil samples are tested under isolated raft foundation of dimensions 120×120 mm subjected to vertical static and cyclic loading of frequency 2Hz and continued for 50 seconds. The results showed a significant improvement in soil bearing capacity when reinforced with stone columns despite the small area replacement ratio, where the bearing capacity of improved soil increased by 120 to 145%. The compressibility of improved soil decreased by 57 to 86% in comparison with that of natural soft soil. Also, the floating stone columns reduced the porewater pressure, where the stone columns considered efficient in providing short drainage pathways. This can be one of the reasons why soil reinforced with floating stone columns hold higher cyclic and static stresses regardless the end bearing of stone columns.

scholarly journals Effect of several patterns of floating stone columns on the bearing capacity and porewater pressure in saturated soft soil

2021 ◽  
Author(s):  
Mahdi Karkush ◽  
◽  
Anwar Jabbar ◽  
Keyword(s):  
Bearing Capacity ◽  
Soft Soil ◽  
Ultimate Bearing Capacity ◽  
Geotechnical Properties ◽  
Stone Columns ◽  
Stone Column ◽  
Angle Of Internal Friction ◽  
Design Requirements ◽  
The Common ◽  
Porewater Pressure

One of the common geotechnical problems is the construction on soft soil and the improvement of its geotechnical properties to meet the design requirements. A stone column is one of the well-known techniques used to improve the geotechnical properties of soft soils. Sometimes thick layers of soft soil imposed the designer to use floating stone columns for improvement of such soil; in this case, the designer will be lost the end bearing of the stone column. In this study, the effects of several patterns of floating stone columns distribution under footing on the bearing capacity of soil and the distribution of excess porewater pressure are investigated. The soft soil used in this study has a very low undrained shear strength (cu) of 5.5 kPa and improved by several patterns of stone columns (single, two linear, triangular, square, and quadrilateral). The stone column has a length of 180 mm and a diameter of 30 mm. The material of the stone column is poorly graded sand has an angle of internal friction (48.5°) at a relative density of 65%. The results indicated a significant increase in the ultimate bearing capacity of soft soil when treated with floating stone columns despite the small ratio of area replacement and reducing the excess porewater pressure and settlement. Also, the ultimate bearing capacity of soil calculated from experimental work is compared with the corresponding values obtained from the proposed equations in the previous studies to evaluate the validity of using such equations.

Model Test of Bearing Capacity of WasteTire Assembly Foundation on Soft Soil Layer

2021 ◽  
Vol 69 (7) ◽  
pp. 263-269
Author(s):  
Me ti ◽  
Tri Harianto ◽  
Abdul Rachman Djamaluddin ◽  
Achmad Bakri Muhiddin
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Soft Soil ◽  
Soil Layer

Improvement of Soft Soil by Stone Column Treated with Bentonite

2020 ◽  
Vol 857 ◽  
pp. 283-291
Author(s):  
Safa Hussain Abid Awn ◽  
Jasim M. Abbas
Keyword(s):  
Clayey Soil ◽  
Slenderness Ratio ◽  
Soft Soil ◽  
Field Tests ◽  
Stone Column ◽  
Laboratory Model ◽  
Mix Proportion ◽  
Effective Depth ◽  
Concrete Footing ◽  
The Ideal

Soft clayey soils cover wide Iraqi areas specially the regions close to rivers and the southern part of this country Heavy weight structures like: highways, dams, multiple story buildings are suffering unacceptable settlement, when constructing on soft soils. The high contamination of water in such soils decrease the effective stress and reduce bearing capacity. The need was appeared to improve such problematic soil by the use of new technique of stone column treated with different percentages of natural bentonite by a series of field tests using full scale concrete footing constructed on soft soil in addition to a laboratory model to investigate settlement with time at constant stress. The soil that used in this study is natural clayey soil, brought from a location south of Diyala governorate, from a farm area. The study includes also: The effect of stone column diameter treated with bentonite on the behavior of footing constructing on soft clayey soil, The effect of stone column length on the behavior of footing on such soils. Results of field and laboratory model tests reviled that the treated model by stone column mixed with 40% bentonite is the ideal one, which reduces the settlement by 55%. In other hand problems of uneven settlements appear when using 60% bentonite as a mix proportion. The Ideal slenderness ratio (Ds/Ls<25%). The effective depth of stone column treated with bentonite is (1/3H).

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