Skip to content

Study on the effects of deformation control for embankment during liquefaction by using geosynthetics sandwiched between gravel

Road embankments are damaged due to settlements or deformations or both due to soil liq-uefaction from earthquakes. Due to these settlements and deformations, cracks and gaps form on the pave-ment and because of this, emergency vehicles cannot be driven at the time when they are most needed. We are attempting a new construction method to reduce embankment deformation from soil liquefaction by laying a structure, which sandwich high strength geosynthetics fibers between layers of crushed stones, directly beneath an embankment. This method does not completely eliminate soil liquefaction and enable to some embankment deformations. However the road is at a restorable level even after an earthquake by limiting the settlement and the lateral deformations. Small scale shaking table tests in a 1-g gravity field were carried out to evaluate effectiveness of a defor-mation mitigation method for road embankment during liquefaction by using gyosynthetics sandwiched between gravel. The gravel layer could dissipate an excess pore water pressure during liquefaction imme-diately, and restrained a shear deformation under the embankment because of its high permeability. Fur-thermore, the composite layer which consisted of the gravel with geosynthetics could perform as a rigid plate with high permeability. As a result, the improved layer could restrain the deformation of embankment, and this effect could keep shape of embankment.