Soil reinforcement using geosynthetics is a very attractive alternative for highway embankment and retaining wall projects because of the economic benefits it offers in relation to cenventional retaining structures. Desigh of reinforced soil slopes is typically performed using software-based techniques (limit equilibrium), which require significant assumptions regarding the distribution of strains within the reinforcement elements. However, to date, the assumed strain distributions have not been fully validated against monitored results. One consequence of this is a perceived overconservatism in design.
The overall objective of this research initiative is to generate and integrate (via centrifuge modeling, digital image analysis, and finite element analysis) data that will provide a definite answer regarding the strain distribution to be adopted in reinforced soil slope design. Specificaly, this project will integrate results from the following five phases: (i) a centrifuge modeling investigation undertaken to generate experimental data on the performance fo geosynthetic reinforced soil slopes under working stress conditions; (ii) a digital image processing and analysis effort performed to collect and evaluate strain information from inflight-captured images of videotaped centrifuge models; (iii) a numerical (finite element) study performed to compile parametric evaluations of reinforced soil slope behavior, after having calibrated numerical procedures against data collected in the previous experimental phase; (iv) an evaluation effort to incorporate findings on reinforcement strain distribution into current reinforced soil guidelines; and (v) an educational component to integrate digital video clips of centrifuge geotechnical models into multimedia presentations to be used for undergraduate and graduate geotechnical instructions as well as for recruitment of underrepresented minority high school students into engineering programs.
In addition to the specific goal of refining design guidelines for geosynthetic reinforced soil slopes by gaining better understanding of the pattern of strain distributions, the proposed research is the cornerstone of larger, ongoing agendas under active development on reinforced soil research by the PI and on geotechnical modeling at the PI's institution. In fact, the proposed investigation will initiate implementation of innovative procedures invilving digital image analysis in geotechnical centrifuge testing at the University of Colorado, will contribute to ongoing efforts of cross-validation between physical and numerical modeling of geotechnical systems, and will foster integration of research into engineering education.
