Subsection retrusive slip-casting method for porthole slurry-stop mixed double-pipe

Abstract

The invention provides a sectional retreating grouting method for a mixed duplex pipe on the outside of an orifice stop-grouting pipe, comprising the following technological steps that: a shallow hole is drilled on a grouting wall (13) by utilization of a drilling machine at first; a drill rod is retreated; an orifice pipe (11) is arranged and then fixed on the orifice wall by utilization of anchor agents (12); the drill rod with a single drill bit and the structure of an inner sleeve and an outer sleeve is adopted for drilling; one end of the orifice pipe positioned on the outside of the drill hole is connected with a drainage (8) and a water inrush resistant device (6) during the drilling process; tail ends of both an inner pipe (2) and an outer pipe (3) of the drill rod are connected with water supply pipes; drilling is performed through the water inrush resistant device, the drainage and the orifice pipe until the designed drilling depth is reached; the water inrush resistant device is disassembled; a hollow pressure plate (5) and a stop-grouting plug (7) are sleeved on the drill rod; the water supply pipes on tail ends of the inner pipe and the outer pipe are respectively connected with a cement slurry supply pipe and a water glass slurry supply pipe; grouting is performed and cement slurry is driven to be ejected from the front of the drill bit along the inner pipe, and simultaneously the cement slurry and water glass slurry are ejected respectively from a water and slurry outlet hole (16) and a water and slurry outlet hole (17) on the front section of the inner pipe and the outer pipe, mixed on the outside of the pipes and then enter into the stratum; when the designed grouting quantity is reached, the drill rod is released by the stop-grouting plug; after the drill rod is retreated for a section of distance, the stop-grouting plug is sealed again, and a gap between the drainage and the outer pipe is grouted continuously; in such manner.

Description

technical field [0001] The invention belongs to the advanced grouting reinforcement and water blocking technology of weak surrounding rocks in tunnels and underground engineering, and mainly proposes a segmented retreat grouting method with double-pipe mixing outside a grout stop pipe at an orifice. Background technique [0002] In the construction of tunnels and underground projects in weak and broken water-bearing strata, the most likely problems are large deformation and collapse of the surrounding rock, water gushing and mud inrush at the excavation surface, endangering the safety of personnel and equipment, causing casualties, and in severe cases, causing surface collapse. The groundwater level drops, affecting the normal life of residents and causing damage to the ground environment. In order to ensure construction safety, the currently commonly used ground reinforcement and water blocking method at home and abroad is the grouting method. The grouting method is to inje...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to propose a double-pipe step-back grouting method for mixing outside the grout stop pipe at the orifice, so as to solve the problem of pipe sticking during double-pipe grouting, and at the same time ensure the mixing of the grout and the grouting pressure. Improve grouting effect

[0005] The double-pipe segmental retreat grouting method proposed by the present invention uses a single drill bit and double-pipe drill pipe drilling and segmental retreat grouting, which effectively solves the problem of the existing double-pipe grouting The existing problem is that during grouting, the grouting liquid is sprayed from the front of the drill bit and around the drilled hole and mixed to make the grout mix evenly and ensure the grouting quality of the drilled hole; the grouting stopper is used to close the hole so that the grouting The outflow of the orifice ensures the pressure and effect of grouting, simplifies the construction process and improves the efficiency of grouting

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