Vertical shaft construction method under unfavorable geological condition

Abstract

The invention discloses a vertical shaft construction method under a unfavorable geological condition, comprising the following construction steps of: 1, pouring cover-weight concrete at a position wherein a well head of a vertical shaft is; 2, arranging two circles of advance consolidation grouting holes in the cover-weight concrete and arranging anchor bar bundles in the grouting holes, wherein the depths of the grouting holes are the same as the depth of the vertical shaft and the depths of the anchor bar bundles are the same as the depths of the grouting holes; 3, drilling pilot holes from top to bottom of the vertical shaft by utilizing a raise-boring machine; 4, drilling pilot shafts from bottom to top of the vertical shaft by utilizing the raise-boring machine; 5, carrying out advance support before expanding excavation; 6, carrying out hole drilling , blasting and the expanding excavation from top to bottom on the vertical shaft; and 7, carrying out reinforced support after the expanding excavation. By means of the vertical shaft construction method disclosed by the invention, the problems of the excavation of the light-section deep vertical shaft under the unfavorable geological condition are solved; and through the advance consolidation before the pilot hole construction, the advance support of small pipes before the expanding excavation and the steel support and bolt-spray support after the excavation, the influences of hole collapsing during the pilot shaft excavating and collapse after the expanding excavation on the construction are effectively eliminated.

Description

technical field [0001] The invention relates to the technical field of shaft construction methods, in particular to a shaft construction method under adverse geological conditions. Background technique [0002] At present, shaft construction is difficult, especially in some unfavorable geological conditions. The so-called unfavorable geological conditions refer to: the depth is greater than or equal to 100m, the diameter is less than or equal to 4m, and the development stability of rock cracks at the location of the shaft is poor. It is dark gray argillaceous slate, with thin layer structure, dominated by Type IV and V surrounding rocks, densely developed fractures, fractured surfaces and thin layered rock formations are interlaced and sheared, and the rock mass presents a large number of fragmented blocks and argillaceous state. The pressure shaft has a circular cross-section, its excavation diameter is less than or equal to 4m, and the well depth is greater than or equal ...

AI Technical Summary

Problems solved by technology

The pressure shaft has a circular cross-section, its excavation diameter is less than or equal to 4m, and the well depth is greater than or equal to 100m. Especially when the surrounding rock of the well wall is broken, the strength is low, the stability is poor, the groundwater is abundant, and the construction conditions are harsh, it is difficult to organize the construction according to the general construction method , thus affecting the realization of the overall construction progress target of the hydropower station

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