Field and laboratory experiments to evaluate the effects of improvement techniques on seismic performance of highway embankments

Highway embankments have experienced earthquake-induced damages from minor to catastrophic scales during the past few decades despite the fact that highways are considered as major lifelines that should be in continuous operation under any circumstances. Recent advances in highway engineering suggest that geosynthetic reinforcement can be considered as a novel approach to mitigate earthquake hazards on highway embankments by reducing the effects of earthquake-induced dynamic forces successfully. The objective of this thesis is to assess the seismic performance of highway embankments as well as to evaluate the effects of improvement techniques in terms of dynamic performance of the models by performing a series of full-scale seismic performing tests and reduced scale shaking table experiments. Field experiments include the dynamic performance tests of unreinforced, geogrid reinforced and EPS geofoam highway embankments in the proposed test area using the Mobile Seismic Shaker. Local site conditions and the wave propagation properties of the test area have been investigated with the help of the geophysical and geotechnical experiments. before the full-scale seismic performance test stage. A series of shaking table tests of the 1/10 scale of the shake table models were performed. The experimental results were evaluated comparing the acceleration and displacement responses of the highway embankment models. Obtained results from full-scale experiments reveal that transmitted accelerations are up to 68.8% and 80%, and displacements are up to 95.1% and 99.3% less for the geogrid reinforced and EPS geofoam embankment models. Similar results were also obtained from shaking table experiments as geogrid reinforcement and EPS geofoam inclusions can notably enhance the structural stability and resilience of the embankment.