The invention provides a roadbed having a
pile-net combination structure and a construction method thereof, which solves the technical problems that soft-soil foundation in superlarge area cannot be treated effectively and post-construction settlement cannot be effectively overcome in the prior art. The roadbed comprises prestress tubular piles (1), prestress tubular
pipe caps (2), a prestress tubular
pile ground beam (3) and a
cushion layer (4), wherein the
cushion layer (4) sequentially consists of a first gravel
cushion layer (5), a first medium-coarse sand cushion layer (6), a
geogrid (7), a second medium-coarse sand cushion layer (8) and a second gravel cushion layer (9) from bottom to top. The thickness of each gravel cushion layer is 25mm, the grain
diameter of gravel in the gravel cushion
layers is smaller than or equal to 3mm, the
silt content of the gravel cushion
layers is smaller than or equal to 5%, the thickness of each medium-coarse cushion layer is 5mm, the
silt content of the medium-coarse cushion
layers is smaller than or equal to 5%, bidirectional tension strength of the
geogrid (7) is larger than or equal to 80 kilonewton / m, extension rate of the
geogrid (7) is smaller than or equal to 15%, and compacting factor of the cushion layer (4) is smaller than 0.9. The invention further discloses a construction method of the roadbed. The roadbed is low in general manufacturing cost and has excellent
economic benefits and popularization value.