Numerical analysis of geosynthetic-bridged and drilled shafts-supported embankments over large sinkholes

ABSTRACT: This paper proposes a method to remedy sinkhole problems in highway projects by placing a geosynthetic layer over the drilled shaft walls to support the embankments. Two calibrations were first conducted to verify the numerical model using FLAC2D for this kind of problem. One calibration was based on a field study of a gesosynthetic-reinforced, column-supported embankment. The second calibration was based on a full-scale geosynthetic-bridging over void test. A baseline case representing typical material properties and model geometry in real projects was selected and analyzed, which included a 5-m high embankment over a 20-m wide void supported by a geosynthetic layer over drilled shafts at 3-m spacing. The analysis included the settlement, the tension in the geosynthetic layer, and the total axial force in the shafts. Settlements at the crest and base of the embankment were calculated to evaluate the performance of this embankment system. The numerical results indicate that higher tension in the...