Drainage structure for soft foundation

The invention discloses a drainage structure for a soft foundation, and relates to the technical field of foundation drainage. The problem of foundation settlement caused by continuous drainage of a drainage channel is solved. The drainage structure comprises a sandbag filled with sandstones and a sand well used for installing the sandbag, the drainage structure further comprises a water stop mechanism installed in the sandbag, the water stop mechanism comprises a positioning rod, a first water stop disc and a second water stop disc, wherein the positioning rod is installed in the sandbag; the first water stop disc is coaxially fixed to the bottom of the positioning rod, an opening for discharging sand is formed in the bottom of the sandbag, and the peripheral wall of the first water stop disc is in sealed connection with the inner wall of the opening of the sandbag so as to prevent the sand from being discharged; and the second water stop disc is coaxially fixed to the positioning rod, and the outer peripher