Method for constructing strengthened saturated-flow plastic silt soft soil foundation

The invention belongs to the field of the civil construction and particularly relates to a method for constructing a saturated-flow plastic silt soft soil foundation. According to the technical scheme of the invention, the method comprises the followings steps: excavating a main groove to be 2-3m under the ground surface in a construction area for the first time, and excavating water collection pits for dewatering in time in the main groove; excavating the main groove to be 4-6m under the ground surface for the second time, and excavating water drainage pits and water collection pits in the main groove, and dewatering until silt in the main groove is solidified; throwing single blocks with larger diameter into the silt, and loading layer by layer by using a vibrating roller to form the frameworks of the single blocks with larger diameter in the silt; and carrying out integral silt ballasting, extruding and replacing to the upper parts and the gaps of the frameworks of the single blocks by adopting the backfill with good size gradation to form a composite foundation with scattered frameworks and integral silt extruding platforms combined, wherein the backfill needs to be pervious to water and repellent to silt. The saturated-flow plastic silt soft soil foundation saves the construction investment, shortens the construction period, occupies less land, is environmental friendly, has wide adaptability and a good strengthening effect and can be constructed in winter.