Three-dimensional calculation methods on global stability safety factor of diaphragm wall slurry trench based on minimum potential energy principle

Due to the unreasonable assumptions for the three-dimensional (3D) sliding surface, the calculated results of the global stability safety factor (GSF) of the diaphragm wall slurry trench are often excessively large. In order to improve this phenomenon, the 3D calculation model on the GSF of trench wall is established by assuming the sliding surface to be a quarter ellipsoidal surface and the sliding mass to be a quarter ellipsoid. Then the 3D energy method is proposed based on the minimum potential energy principle, and further the 3D equivalent energy method is also come up with adopting the equivalent trench length to replace the actual trench length. The correctness of the models established and the rationality of the calculation methods proposed are verified based on ten engineering cases and the sensitivity of the GSF to various parameters is analyzed on the basis of seven design examples. Finally, the different calculation methods are used to check the global stability of the slurry trenches in practical engineering, the results prove that the calculation methods presented are rationality once again and the 3D equivalent energy method has better engineering applicability.