Assembly type foundation pit inner supporting structure and grouting construction method thereof

The invention relates to the technical field of foundation pit supporting, and discloses an assembly type foundation pit inner supporting structure and a grouting construction method thereof.The assembly type foundation pit inner supporting structure comprises a bearing piece, a supporting piece and a fixing piece, and the supporting piece comprises a first supporting part and a plurality of second supporting parts; the fixing piece comprises a first fixing part and a second fixing part; the bearing piece, the supporting piece and the fixing piece each comprise a hollow shell, reinforcing steel bars are preassembled in the shells, communicating holes communicating with one another are formed among the bearing piece, the first supporting part, the second supporting part and the fixing piece, and grouting holes are formed in the top of the first supporting part and the top of the second fixing part. The integral structure of the foundation pit support is simplified, the reinforcement cage can be directly formed