Pre-buried guide pipe assembly suitable for tunnel curtain grouting with extra-high water pressure and pre-burying method

Abstract

The invention discloses a pre-buried guide pipe assembly suitable for tunnel curtain grouting with extra-high water pressure and a pre-burying method. A pre-buried guide pipe and a pipe head are used; the pre-buried guide pipe comprises a pipe body, a pipe tail, a pipe cap and a filling bag, the pipe body and the pipe tail are in threaded connection and are both steel pipes, the communicating guide pipe of the pipe body and the pipe tail is filled with the filling bag, the filling bag is a rubber bag, and the length of the filling bag is the same as the sum of the length of the pipe body and the length of the pipe tail; when a grouting stopping wall is poured, the pipe cap is arranged at the head end of the pipe body in a sleeving mode and used for protecting an external thread at the head end of the pipe body; during grouting, the pipe cap is removed; during grouting, the tail end of the pipe head is in threaded connection with the head end of the pipe body; and the head end is used for being connected with a grouting pipe. By using the pre-burying method, in tunnel curtain grouting construction, the pre-buried guide pipe assembled in a segmented mode is designed and pre-buried into the grouting stopping wall to be integrally poured and formed, the tedious positioning and hole forming work in conventional curtain grouting construction is avoided, and damage to the grouting stopping wall is avoided.

Description

technical field [0001] The invention belongs to the technical field of tunnel grouting reinforcement, and in particular relates to a pre-embedded guide pipe assembly and a pre-embedded method for tunnel curtain grouting suitable for ultra-high water pressure. Background technique [0002] The buried depth and length of the tunnel continue to increase, and the tunnel faces the problems of high water pressure and large water output during construction. In the conventional tunnel curtain grouting construction, after the grout stop wall is constructed, guide pipes need to be designed and installed according to the grouting plan, and after the grout stop wall is drilled, guide pipes are inserted, and hemp silk, cement, anchoring agent, etc. Fill the gap between the guide pipe and the drill hole, and start drilling and grouting along the guide pipe after the guide pipe is installed firmly. In the process of constructing the guide pipe, there are three problems: first, the tunnel ...

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Problems solved by technology

In the process of constructing the guide pipe, there are three problems: first, the tunnel curtain grouting requires a large number of boreholes. According to the size of the tunnel section and surrounding rock conditions, the number of boreholes for the grouting scheme can reach 60-150; and The position of each hole is different, and the spatial angle is different. When the drilling rig initially opens the hole in the grout wall to install the guide pipe, it needs to use the compass and line ruler to repeatedly move the position and adjust the angle, which takes a long time and has deviations in positioning; the second is Intensive drilling in the grout-stop wall caused great damage to the wall, and the subsequent grouting process was prone to cracking and leakage of the grout-stop wall; the third is to grout in high water pressure formations with higher grouting pressure. The anchoring strength of the pipe will not fly out during the grouting process, and the length of the guide pipe needs to be greatly increased, which brings great inconvenience to the construction and also causes a waste of materials

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