Simple calculation method for maximum principal stress of underground diaphragm wall in excavation stage

The invention relates to the technical field of calculation of main stress of an underground diaphragm wall, and particularly relates to a simple calculation method for the maximum principal stress ofan underground diaphragm wall in an excavation stage. The method comprises the following steps: S1, establishing a model of the diaphragm wall excavation stage, wherein the model comprises a diaphragm wall, a bottom plate, a lining and a filling core, the diaphragm wall is a semicircular cylinder, the bottom plate is arranged at the bottom of the model, the lining is tightly attached to the innerside of the diaphragm wall, and the model is filled with the filling core; s2, simplifying the diaphragm wall into a cylindrical curved surface, selecting one cylindrical curved surface on the diaphragm wall, and establishing a curved surface coordinate system on the cylindrical curved surface; and S3, solving a calculation formula of the maximum principal stress of the underground diaphragm wall. According to the method,