Behaviour of prestressed geotextile-reinforced sand bed supporting a loaded circular footing

In the past, the beneficial effects of prestressing the geosynthetic in reinforced soil foundations have been studied mathematically. It is timely to experimentally investigate the degree of improvement generated by prestressing the geosynthetic layer for several embedment depths of a footing resting on a reinforced sand bed. Therefore, laboratory physical model tests and finite element analyses were conducted to study the behaviour of prestressed geotextile-reinforced sand bed supporting a loaded circular footing. The addition of prestress to the geotextile reinforcement results in significant improvement to the settlement response and the load-bearing capacity of the foundation. For a surface footing, the load-carrying capacity at 5 mm settlement for the prestressed case (with prestress equal to 2% of the allowable tensile strength of the geotextile) is approximately double that of the geotextile-reinforced sand without prestress. The beneficial effects of the prestressed geotextile configuration were evident for greater footing depths, in comparison with unreinforced and reinforced (without prestress) counterparts. Experimental and numerical results were also used to validate a few empirical relationships, which are commonly used for solving soil-structure interaction problems. The results obtained from finite element analysis using the program, PLAXIS are generally found to be in reasonabaly good agreement with experimental results.

[1]  C. R. Patra,et al.  Bearing capacity of embedded strip foundation on geogrid-reinforced sand , 2005 .

[2]  Madhira R. Madhav,et al.  A NEW MODEL FOR GEOSYNTHETIC REINFORCED SOIL , 1988 .

[3]  Temel Yetimoglu,et al.  BEARING CAPACITY OF RECTANGULAR FOOTINGS ON GEOGRID-REINFORCED SAND. DISCUSSION , 1994 .

[4]  J. M. Duncan,et al.  Nonlinear Analysis of Stress and Strain in Soils , 1970 .

[5]  G. Gladwell,et al.  Elastic Analysis of Soil-Foundation Interaction , 1979 .

[6]  George Geoffrey Meyerhof,et al.  Some recent research on the bearing capacity of foundations , 1963 .

[7]  Michael T. Adams,et al.  LARGE MODEL SPREAD FOOTING LOAD TESTS ON GEOSYNTHETIC REINFORCED SOIL FOUNDATIONS , 1997 .

[8]  V A Guido,et al.  BEARING CAPACITY OF A GEOTEXTILE-REINFORCED FOUNDATION. PROCEEDINGS OF THE ELEVENTH INTERNATIONAL CONFERENCE ON SOIL MECHANICS AND FOUNDATION ENGINEERING, SAN FRANCISCO, 12-16 AUGUST 1985 , 1985 .

[9]  K. L. Soderman,et al.  STABILIZATION OF VERY SOFT SOILS USING HIGH STRENGTH GEOSYNTHETICS: THE ROLE OF FINITE ELEMENT ANALYSES , 1987 .

[10]  Jian-Hua Yin,et al.  Fundamentals of Geosynthetic Engineering , 2006 .

[11]  R. Krishna Kumar,et al.  SETTLEMENT OF REINFORCED SAND IN FOUNDATIONS , 1997 .

[12]  K. Terzaghi,et al.  EVALUATION OF COEFFICIENTS OF SUBGRADE REACTION , 1955 .

[13]  Robert M. Koerner,et al.  Designing with Geosynthetics , 1986 .

[14]  Sanjay Kumar Shukla,et al.  The effect of prestressing on the settlement characteristics of geosynthetic-reinforced soil , 1994 .

[15]  Gwe Milligan,et al.  MODEL TESTING OF GEOGRIDS UNDER AN AGGREGATE LAYER ON SOFT GROUND. POLYMER GRID REINFORCEMENT: PROCEEDINGS OF A CONFERENCE SPONSORED BY THE SCIENCE AND ENGINEERING RESEARCH COUNCIL AND NETLON LTD AND HELD IN LONDON 22-23 MARCH 1984 , 1985 .

[16]  Sanjay Kumar Shukla,et al.  A generalized mechanical model for geosynthetic-reinforced foundation soil , 1994 .

[17]  Braja M. Das,et al.  Shallow Foundations: Bearing Capacity and Settlement , 1999 .

[18]  D. Chang,et al.  COMPARISON OF GEOGRID AND GEOTEXTILE REINFORCED EARTH SLABS , 1986 .

[19]  Joseph E. Bowles,et al.  Foundation analysis and design , 1968 .

[20]  Braja M. Das,et al.  Ultimate bearing capacity of shallow foundations on sand with geogrid reinforcement , 1993 .

[21]  Sandy Ground,et al.  DEEP-FOOTING AND WIDE-SLAB EFFECTS IN REINFORCED , 1997 .

[22]  E. E. Cook,et al.  The bearing-capacity of a strip foundation on geogrid-reinforced sand , 1993 .

[23]  E. C. Shin,et al.  Experimental Study of Bearing Capacity of a Strip Foundation on Geogrid-Reinforced Sand , 2000 .

[24]  T. G. Sitharam,et al.  Model studies of embedded circular footing on geogrid-reinforced sand beds , 2004 .