Comparison of dynamic characteristics between netted and packaged reinforced soil retaining walls and recommendations for seismic design

In order to compare the seismic responses of netted and packaged reinforced soil retaining walls, large-scale shaking table tests are performed. Based on the earthquake damage investigation, it is found that the failure modes of the reinforced wall are mainly characterized by loose deformation of local blocks under earthquake, and that the overall collapse is rare. Compared with the netted reinforced soil retaining wall, the packaged one has smaller deformation. Under the same magnitude of earthquake, the acceleration amplificatory coefficient of the packaged reinforced soil retaining wall is smaller than that of the netted one, while the value of horizontal peak dynamic earth pressures of the former is substantially larger than that of the latter. It is because the soil is constrained effectively by the wall plate of the packaged reinforced soil retaining wall. Therefore, for the selection of the reinforced soil retaining wall in earthquake-resistance protection zone, especially the buildings in high earthquake intensity regions, the packaged reinforced soil retaining wall will be an optimal choice. Through analysis, for the aseismic design of flexible walls, while maintaining the integral stability of the reinforced soil retaining wall, local-deformation control should be paid attention to, and its the maximal displacement should be less than the allow able displacement under earthquake. In order to maintain the normal use of the road, the deformation exponent of the reinforced soil retaining wall should be smaller than 4%. If the deformation exceeds the allowable value, measures will be taken including increasing the compaction of filling materials and geogrid length as well as the thickness of the wall, and reducing its wall slope can reduce the displacement.