Prediction of Drained Settlement and Ultimate Bearing Capacity for Stone Columns Supported Foundation

2017 ◽  
pp. 12-19 ◽  
Author(s):  
Kok Shien Ng
Keyword(s):  
Bearing Capacity ◽  
Ultimate Bearing Capacity ◽  
Stone Columns

scholarly journals Optimization of the Ultimate Bearing Capacity of Reinforced Soft Soils through the Concept of the Critical Length of Stone Columns

2021 ◽  
Vol 7 (9) ◽  
pp. 1472-1487
Author(s):  
Nour El Islam Boumekik ◽  
Mohamed Labed ◽  
Mekki Mellas ◽  
Abdelhak Mabrouki
Keyword(s):  
Bearing Capacity ◽  
Numerical Models ◽  
Critical Length ◽  
Ultimate Bearing Capacity ◽  
Analytical Equation ◽  
Stone Columns ◽  
Length Ratio ◽  
Soft Soils ◽  
Bearing Capacity Ratio ◽  
Capacity Ratio

The objective of this paper is to develop an analytical equation based on the concept of the critical-length of columns in order to optimize the ultimate bearing-capacity of soft soils, supporting a strip footing and reinforced by a group of floating stone columns. Optimization procedure was performed on three-dimensional numerical models simulated on the Flac3D computer code, for various soft-soils with different undrained-cohesions (Cu=15–35kPa), reinforced by columns of varying lengths (L) and area replacement ratio (As=10-40%), considering different footing widths B. Obtained results indicate that the optimal bearing-capacity ratio (Ultimate bearing-capacity of reinforced soil/unreinforced soil) is reached for the column critical-length ratio (Lc/B) and increase with increase of the later ratio, depending  on As and Cu. Analysis of results also showed that the optimal values of the bearing-capacity ratio in the reinforced soils remain bounded between the lower and higher values (1.28-2.32), respectively for minimal and maximal values of the critical-length ratio (1.1) and (4.4). Based on these results, a useful analytical equation is proposed by the authors, for the expression of the critical-length; thus ensuring an optimal pre-dimensioning of the stone columns. The proposed equation was compared with the data available in the literature and showed good agreement. Doi: 10.28991/cej-2021-03091737 Full Text: PDF

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.

Experimental Investigation for Horizontal Ultimate Bearing Capacity and Target Ductility Factor Improvement Results of the RC Column Reinforced by AFL with Damages

2014 ◽  
Vol 488-489 ◽  
pp. 497-500
Author(s):  
You Lin Zou ◽  
Pei Yan Huang
Keyword(s):  
Bearing Capacity ◽  
Ultimate Bearing Capacity ◽  
Test Results ◽  
Rc Columns ◽  
Static Test ◽  
Rc Column ◽  
Ductility Factor ◽  
Secant Stiffness ◽  
Function Relationship ◽  
Reversed Cyclic

Deem test results from the low reversed cyclic loading quasi-static test with 2 RC columns as the basic information of secant stiffness damage of the reference column and take use of the TMS instrument in the test to artificially make the damage percentage of secant stiffness of the RC column as 33%, 50% and 66%, 6 damaged columns in total; reinforce the 6 damaged columns and 2 undamaged ones under the same conditions with AFL, through quasi-static contrast test. Test results show that it is able to effectively boost horizontal ultimate bearing capacity and ductility deformability of the RC columns with AFL for reinforcement; besides, there is a linear function relationship between horizontal ultimate bearing capacity, target ductility factor, and damage percentage of secant stiffness.

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