In-situ reconstruction and extension structure of embankment and construction method thereof

An in-situ reconstruction and extension structure of an embankment, comprising:

• a stepped slope, wherein the stepped slope is formed by excavation on an existing side slope, a gradient of the stepped slope is the same as a gradient of an extension side slope, the stepped slope is intersected with each of a top plane and a bottom plane of the existing side slope;
• and
• a toe of the existing side slope is taken as a toe of the extension side slope, and the gradient of the extension side slope is determined according to a position of the toe and an expanded width of the extension side slope;
• wherein an outer side of the stepped slope is filled with a geogrid reinforcement layer in a layered manner, and a slope protection structure is arranged on an outer side of the geogrid reinforcement layer to form the extension side slope;
• and
• wherein a drainage system is arranged at a bottom of the extension side slope and configured for draining water seepage inside in-situ reconstruction and extension structure of an embankment,
• wherein excavation of the stepped slope starts from the toe of the existing side slope and extends towards an inner side of the embankment to divide the embankment into a plurality of sub-level construction areas;
• and
• before the excavation of the stepped slope, a top of a tail end of each of the plurality of sub-level construction areas has steel sheet piles punched therein and slip-casting pipes are prefabricated at a corner of the steel sheet piles.