A cone-wedge active device and construction method for internal support in foundation pit engineering

Abstract

The invention discloses a cone-wedge active device and its construction method for internal support in foundation pit engineering. Under the action of multiple rows of high-strength bolts, the device bears and transmits the axial force of the steel support by clamping the conical outriggers with two splints. The angle between the splint and the contact surface of the tapered leg is 30°. The vertical positioning is determined by adjusting the high-strength bolts, and the axial force can be withstand by tightening the bolts. The splint of the cone-wedge activating device is in smooth contact with the conical leg, and the high-strength bolts pass through the bolt grooves of the conical leg and are fixed on the splints on both sides, which can not only effectively bear the pressure of the steel support shaft, but also bear The tensile force of the outward deformation of the soil layer, and the integrity of the purlins and steel supports have been improved. It changes the concept of driving the rigid wedge into the traditional active device, increases the contact surface, and uses the high-strength bolts to pull the wedge, and the more the cone wedge is pressed, the tighter it is. It ensures the integrity of the foundation pit support system and reduces the risk of steel support falling off.

Description

technical field [0001] The invention relates to a cone-wedge type activating device for internal support of foundation pit engineering, which mainly improves the form and process of the traditional steel supporting activating device, and belongs to the technical field of infrastructure construction auxiliary workpieces. Background technique [0002] The steel support of the foundation pit is widely used in the construction of the open excavation method. In engineering, Φ609 steel pipe support with a wall thickness of 16mm is generally used. The active device on the top is adjusted. In both methods, after applying the pre-loaded axial force with the jack, the steel wedge is driven in, and the jack is removed after being stabilized. The disadvantages of these two types of active devices are: the steel wedge force transmission method is unreliable, and it is easy to cause stress concentration and eccentric force; the single row of steel wedge steel support is unstable in later...

AI Technical Summary

Problems solved by technology

The angle between the splint and the contact surface of the tapered leg is about 30°. The vertical positioning is determined by adjusting the high-strength bolts, and the axial force can be withstand by tightening the bolts, which solves the problems of poor integrity and unreliable force transmission of the current steel support system.

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