Treatment method for collapse of steel sheet pile supporting structure

The invention discloses a treatment method for collapse of a steel sheet pile supporting structure, which comprises the following steps of: 1, carrying out foundation pit excavation on an area with serious collapse, judging whether the bottom of a first steel sheet pile is skirted and whether a second supporting structure is deformed, and if the skirting and the deformation are confirmed, judging whether the second supporting structure is deformed; the earthwork is backfilled to the position of the second supporting structure, and the damaged second supporting structure is reinforced; thirdly, a groove is excavated in the bottom of the foundation pit; fourthly, concrete is poured into the groove, a pipe pile is arranged, and the damaged second supporting structure is replaced; fifthly, the next section of groove is constructed, and the second step to the fourth step are repeated; sixthly, whether the protruding height of the concrete surface in the groove is abnormal or not is observed, and if not, main body