Tensile-strain behaviour of nonwoven needle-punched geotextiles under axisymmetric loading conditions with application to reinforced unpaved roads | |
| Author | Cao Ngoc Hai |
| Call Number | AIT Thesis no. GE-98-14 |
| Subject(s) | Strength of materials Strains and stresses |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | subgrade to improve the performance of reinforced fill layer placed on soft ground. This study concerns with the tension-strain behaviour of a nonwoven needle-punched geotextiles under axisymmetric loading condition as well as the mechanism and effects of the different grades of geotextile on the increasing bearing capacity of reinforced unpaved roads over soft subgrade under traffic load. A method to describe the tensionstrain of geotextile under an axisymmetric loading condition is proposed. This method is verified by the strain energy capacity concept. The in-air stiffness of geotextile under axisymmetric loading condition was obtained. Subsequently, a program of laboratory scale axisymmetric bearing capacity tests under monotonic loading, namely: modifiedCBR test on weathered soft clay overlain by compacted sand, and on weathered soft clay overlain by compacted sand with reinforced with fix-end or free-end nonwoven needlepunched geotextile was carried out which considered the reinforcing mechanism of the different grades of geotextile. Finite element method (FEM) was utilized to back-analyze the results of the modified CBR tests. The results of the finite element analyses fit with the experimental data. It is concluded that there is not significant different between in-air and in-soil stiffness of geotextile reinforcement of unpaved roads. The calculated results indicate an additional load capacity of the geotextile using an axisymmetric stiffness demonstrating a significant contribution of membrane action and the grades of geotextile on the increase in bearing capacity of soil-geotextile system. The effects of the different grades of geotextile obtained in this study can be used to preliminary choose the appropriate grades of nonwoven needle-punched geotextile corresponding to the allowable rut depth in the design of the reinforced unpaved roads under traffic load. |
| Year | 1999 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Geotechnical Engineering (GE) |
| Chairperson(s) | Bergado, Dennes T.; |
| Examination Committee(s) | Balasubramaniam, A. S.;Der-Guey, Lin; |
| Scholarship Donor(s) | Asian Institute of Technology Partial Scholarship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1999 |