Stepped pressurization-grouted anchor rod provided with water absorbing expansion blocks and construction method of stepped pressurization-grouted anchor rod

Abstract

The invention discloses a stepped pressurization-grouted anchor rod provided with water absorbing expansion blocks. The stepped pressurization-grouted anchor rod comprises an anchor rod body; the outer surface of the anchor rod body is uniformly provided with a plurality of water absorbing expansion blocks; the anchor rod body is provided with five rows of grouting holes which are arranged at an equal interval in the length direction of the anchor rod body; the anchor rod body is internally provided with five circles of rubber non-return rings which have equal distance from the grouting holes;four of the rubber non-return rings are inclined toward the head of the anchor rod body so that a pressurizing plate and pull rod combined structure can be conveniently put into the anchor rod body;in a grouting process, the rubber non-return rings provide step-back resistance for a pressurizing plate so as to realize a non-return effect; the rubber non-return rings are gradually thickened fromthe start section to the tail section of the grouted anchor rod body, so the provided resistance is gradually increased; and when the grout pressure is increased until the corresponding rubber non-return ring cannot tolerate, the pressurizing plate and pull rod combined structure automatically steps back to the next rubber non-return ring. The invention further discloses a construction method forthe anchor rod.

Description

technical field [0001] The invention relates to the field of surrounding rock support, in particular to a stepped pressurized grouting bolt with water-absorbing expansion blocks suitable for use in soft soil areas and a construction method thereof. Background technique [0002] With the rapid development of the economy, high-rise buildings and urban underground projects continue to increase, resulting in a large number of deep foundation pit excavation and support projects. In my country's economically developed areas, there are large-scale soft soil strata with high moisture content and poor physical and mechanical properties, which makes anchoring technology more and more important. The existing grouting bolts are difficult to provide good anchoring force in soft soil due to too concentrated grouting and insufficient anchoring force in the later stage. At present, most of the grouting bolts used in the project are one-hole grouting type, which is only grouted at the end, ...

AI Technical Summary

Problems solved by technology

This patent discloses an anchor rod with an external expansion device. The outer surface of the anchor rod is provided with one or more expansion devices composed of an extrusion structure and an expansion structure. When the anchor rod body rotates, the extrusion structure and the expansion device The expansion structures squeeze each other, and eventually any one or both of them form radial expansion. The expanded structure can form a mechanical support on the hole wall of the anchor hole in the rock formation, so that the anchoring force of the bolt is greatly improved. It also has the function of grouting, but there is only one grouting port at the end, and it can only be grouted around the grouting port. The grouting range is too small, and the grout cannot permeate the shaft, so it cannot be well consolidated and improved. body, it is also difficult for the anchor rod to be tightly combined with the soil

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