Influence of reinforcement stiffness and strength on load-settlement response of geocell-reinforced sand bases

摘要

Improvement in the performance of a strip footing supported on geocell-reinforced sand bed is investigated through series of experimental tests on a reduced scale physical model. Geocells with scaled-down mechanical and geometrical properties produced from various material types consisting of woven geotextile, nonwoven geotextile and biaxial geogrid are used as the reinforcement and the influence of geocell strength and stiffness on the enhancement of bearing capacity and settlement of the surface footing is described. The results indicate that stiffness of geocell makes a significant contribution on the performance of geocell-reinforced soil. For the geocells used in the tests with the height equal to footing width, for example at footing settlement ratio of 6%, improvement in the bearing capacity of geocell with the stiffest material is found to be 1.5 times the geocell with the softest material. The failure mechanism of geocell-reinforced foundation system has been shown to depend highly on geocell modulus and height. It is also concluded that ultimate tensile strength of geocell material is generally not influential at load-settlement behaviour of the footing at practical settlement levels. However, if flexural rupture of reinforcement controls the failure mechanism, geocell strength affects the ultimate bearing capacity.