Method for reinforcing soft ground by post-grouting combined with air-boosted vacuum preloading

A method for reinforcing soft ground by post-grouting combined with pressurized vacuum preloading is proposed, by pre-burying prefabricated vertical drains and air-boosted pipes in granular material piles, and the air-boosted pipes are used as grouting pipes to reduce the number of times of piling, which not only improves the construction efficiency, but also reduces the structural disturbance of the soil and the influence of smear effect, thus reducing the impact on the radial permeability and the radial consolidation coefficients. The method does not use geotextile bags for granular materials, which can avoid the problem of forming a localized clogging area around the geotextile bags, and the method not only improves the efficiency of vacuum transfer in a pre-consolidation stage, but also improves the grouting effect in the later stage, effectively enhances the strength of soft soil and makes granular material piles and the surrounding soil form composite ground.