Method for determining slurry weight of double-folded-angle groove section of ultra-deep circular underground diaphragm wall

The invention belongs to the technical field of geotechnical engineering, and particularly relates to a method for determining slurry weight of a double-folded-angle groove section of an ultra-deep circular underground diaphragm wall. The method comprises the following steps: firstly, collecting engineering detailed geological and hydrological data, and then establishing a groove wall overall instability calculation model for a special-shaped groove section; and finally, based on a limit equilibrium method, calculating gliding force and anti-sliding force of a sliding body, and calculating to obtain the minimum slurry weight required for ensuring overall stability. According to the method, for the double-folded-angle groove section of the underground diaphragm wall, influences of various factors such as site overload on stability of a groove wall are considered, and the groove wall overall instability calculation model for double-folded-angle positions is finally established; and the calculation model has the