Assessment of load distribution mechanism in geocell reinforced foundation beds using Digital Imaging Correlation Techniques

The pressure distribution below geocell reinforced foundation beds depends on several factors like height of geocell, weld distance (pocket size), infill material, etc. This paper describes a method to determine the load dispersion mechanism through a geocell layer using a non-contact Digital Image Correlation technique. Series of plate load tests were performed in a test tank having plan dimensions of 0.6 m x 0.6 m and height of 0.65 m. The loading was applied through a strip footing of width 120 mm. Two miniature geocells having heights of 60 mm and 75 mm were used for reinforcing the base layer of the foundation section. The studies were performed with two types of geocells having smooth and rough surfaces. The relative density (RD) of the base and subgrade layers were maintained as 80% and 40%, respectively during the tests. The movement of soil particles was recorded by capturing images at different stages of the test. The images were processed using a Digital Image Correlation (DIC) software to obtain displacement contours and vectors. The results show that the geocells distribute the load over a wide area of the foundation soil. The dispersion angle was found to depend on the height of geocell and the roughness of the geocell surface. The load dispersion angles obtained from Digital Image Correlation analyses of unreinforced and reinforced sections have been compared with similar published results.