Large-cross-section rectangular jacking pipe tunneling soil body improving method

The invention relates to a large-cross-section rectangular jacking pipe tunneling soil body improving method, which comprises the following steps that: a regional division is carried out on the front end surface of a rectangular jacking pipe according to the shape of the cross section; a large cutter head improving region positioned in the middle and a small cutter head improving region arranged around the large cutter head improving region are divided; in the tunneling process, the large cutter head improving region is filled with foam improving agents for soil body improvement; the small cutter head improving region is filled with polymer slurry for soil body improvement; the filling rate of the foam improving agents adapts to the torque of a large cutter head; and the filling rate of the polymer slurry adapts to the torque of a small cutter head. The large-cross-section rectangular jacking pipe tunneling soil body improving method can perfectly solve the problems that the large-cross-section rectangular jacking pipe tunneling of a sandy land layer is difficult, and the excavated surfaces cannot be easily stabilized.