Combined drilling and grouting pipe for grouting reinforcement of soft stratum of island reef and construction method

Abstract

The invention discloses a combined drilling and grouting pipe for grouting reinforcement of a soft stratum of an island reef. The combined drilling and grouting pipe comprises a grouting inner pipe, a grouting outer pipe and an outer end sleeve which are sequentially nested from inside to outside, flower holes are formed in the pipe walls of the grouting inner pipe and the grouting outer pipe, a crown-shaped drill bit is arranged at the tail end of the outer end sleeve, a film bag is bound on the outer wall of the grouting outer pipe, an upper spiral blade is fixed to the outer wall of the tail section of the grouting inner pipe, a small-size rotary drill bit is fixed to the tail end of the grouting inner pipe, and during application, the crown-shaped drill bit and the small-size rotary drill bit are jointly matched for rotary drilling. Meanwhile, the invention further discloses a construction process. A film bag localized key grouting reinforcement technology is adopted, a soft broken zone is subjected to key reinforcement, and a secondary spherical cylindrical grouting diffusion and reinforcement method is adopted; and the grouting effect is good, the grouting inner pipe and the outer end sleeve can be recycled, construction is convenient and fast, economical and practical, repeated drilling is not needed, the soft island reef foundation such as coral sand is effectively reinforced, and disturbance to the soft island reef foundation is reduced.

Description

technical field [0001] The invention relates to a marine geotechnical engineering technology, in particular to a combined drilling and injection pipe and a construction method for grouting reinforcement of weak formations on islands and reefs. Background technique [0002] The Nansha Islands are the most precious land resources in the South my country Sea. They have become an important foothold and forward base in the development of marine resources and territorial sea protection. Accelerating the research on grouting reinforcement technology for weak strata on islands and reefs is conducive to the construction of underground engineering on islands and reefs in my country. and operation and maintenance. The foundations of the island and reef projects in the South China Sea mainly include loose coral sand and weakly cemented reef limestone. Coral sand is a kind of calcareous sand, which is formed by the deposition of marine organisms such as shells, corals, and seaweed. The ma...

AI Technical Summary

Problems solved by technology

The disadvantage of this invention is that the check valve in each section of the grouting pipe is easily blocked by the viscous grout, so that the grout cannot smoothly enter the next section of the grouting pipe, and the grouting sequence of the invention is divided into sections from near to far Sequential grouting may lead to insufficient grout pressure at the end of the grouting pipe, which cannot reach the expected reinforcement depth

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