The invention discloses a fill
subgrade construction method suitable for a water-rich low-
lying permafrost region. The fill
subgrade construction method comprises the following steps of
stamping flagstone silt squeezing replacement construction being conducted; filling a
rubble layer cooling layer; paving two pieces of cloth and one film; paving a gravel layer; constructing a roadbed slope
toe heat preservation protective channel; laying inverted filter
geotextile; paving a gravel layer; paving a gravel
cushion layer; and loading
subgrade filler which is compact in filling and good in water permeability. According to the method,
silt is squeezed and replaced by impacting and rolling the
rubble layer, the
bearing capacity of the foundation is improved, meanwhile, underground water is prevented from rising to roadbed soil under the action of
capillary water, and it is guaranteed that the roadbed is dry; the
rubble cooling layer being filled, good gaps among rubbles being utilized to formnatural
air convection in winter, and the temperature of
permafrost being actively reduced; paving a two-cloth one-film impermeable layer to prevent water in the roadbed body from infiltrating into the
permafrost region. The
water seepage geotextile and the gravel paving layer have high drainage performance, and the roadbed slope
toe heat preservation protective channel prevents
frost heaving diseases of a slope
toe and prevents slope toe
surface water from seeping into a roadbed soil body.