Improvement Of Cohesive Strength Of Local Clay Using Geotextile By Sandwich Technology

Abstract

Geotextiles have been used very successfully in road construction for over 30 years. Their primary function is to separate the sub base from the subgrade resulting in a stronger road construction. The geotextile performs this function by providing a dense mass of fibers at the interface of the two layers. It is suggested that the ability of a geotextile to act as a separator is largely independent of the mechanical characteristic of the geotextile and that strain softening geotextiles can still perform this role when strained past their peak values. A strain energy approach to design is not routine in geotechnical engineering design, as it is difficult to quantify the external energy supplied to the system and the internal energies of the individual components making up the construction. Recent research has suggested that an equivalence of strain energy, between different geotextile types, may exist up to the in service strain. Comparing the actual strain energy and that calculated using a simplified approach shows that significant errors are introduced by firstly ignoring the nonlinear characteristics of the stress-strain curve and secondly by not considering the entire area under the stress-strain curve to rupture of the geotextile. Based on the difficultly in using the strain energy approach in geotechnical engineering design and the significant inconsistencies that can exist in its calculation, it is suggested that the concept of strain energy is not an appropriate parameter for characterising geotextiles.