METHOD FOR DETERMINING SAFE THICKNESS OF SIDE WALL IN KARST AREA OF FOUNDATION PIT, AND GROUTING DEVICE

摘要

Disclosed in the present invention is a method for determining the safe thickness of a side wall in a karst area of a foundation pit, comprising: determining the length m of the side wall, affected by the karst area, of the foundation pit, the length n of the karst area, and steel supporting force F1, air pressure F2 and water pressure F3 of the side wall of the foundation pit; and calculating axial displacement, potential energy and safe thickness of the side wall in the karst area according to the elastic-plastic theory, the law of conservation of energy and the catastrophe theory. Also disclosed in the present invention is a grouting device for a karst area of a foundation pit, comprising a metal net, a water stop plate, a grouting pipe, a water pumping pipe and a one-way communication device. According to the present invention, the risk of water gushing in a karst area of a foundation pit can be quickly eliminated, the problems of slurry injection difficulty, karst water backward suction and the like in construction are solved, a karst area can be blocked, project investment is saved, and construction safety is guaranteed.