2004 Volume 19 Pages 139-146
Advantageous aspects of sandwich-type reinforced earth structures combined with geosynthetics and sand mat are highlighted in this report. Those aspects were elucidated by two kinds of laboratory tests: (1) model footing tests on improvement of bearing capacity and deformation for reinforced earth structures; and (2) large consolidation tests for improvement of hydraulic conductivity, including both vertical permeability and horizontal transmissibility characteristics of geosynthetics. Results from both laboratory tests indicated the following:
i) Sandwich-type reinforcement combined with geosynthetics and sand mats increases stability and decreases deformation of earth structures. In particular, the sandwich structure is effective for providing toughness, which has remained an important issue for reducing infrastructural maintenance and costs.
ii) Hydraulic conductivity of geosynthetics used for this type of earth reinforcement can be maintained for a long period. Such conductivity sometimes disappears, particularly because of clogging when geosynthetics are adopted in embankment construction using fine-grained soils. This fact indicates that the sand mats which are laid above and beneath geosynthetics play a salient role in preventing clogging of geosynthetics that occurs by intrusion of fines from cohesive soils.
