Internal deformation of soil during consolidation in radial drainage condition

The analytical solutions under radial drainage to predict the consolidation behavior of soils with vertical drains generally assume that clayey soils are compressed only in vertical direction. However, soils are also deformed in radial or horizontal directions as consolidation progresses, as proposed by many experts. The radial deformation during consolidation can induce additional excess pore pressure in a soil mass and cause differential settlement and slowed settlement rate. It also can result in unequal void ratio distribution after consolidation, following unexpected deformation behavior. A new consolidation apparatus, which can visually observe and take images of a specimen by using digital camera, was developed. Consolidation test under radial and vertical drainage condition was performed using the new consolidation apparatus and digital image analysis technique was adopted to analyze the consolidation deformation of the specimen. Deformations were successfully measured by suggested method at 420 points of the specimen during the whole consolidation process. Finally, deformation patterns of the specimen were estimated and horizontal deformations were clearly observed as consolidation progressed. Also, void ratio variations measured at the end of consolidation confirmed the radial deformation.