Construction method of hydroelectric power station surge chamber vertical shaft under soft rock geological condition

Abstract

The invention relates to a method for constructing a drilled shaft of a surge chamber in a hydropower station under the condition of weak rock geology; the excavation diameter of the drilled shaft is more than or equal to 20 meters; and the depth of the drilled shaft is more than or equal to 50 meters. The method comprises the following steps: firstly, a safe prestress reinforcing measure is adopted; a prestress anchor rope is arranged in a side slope of the drilled shaft; the deep rock holes in the periphery of the drilled shaft are subjected to consolidation and grouting; the periphery of the drilled shaft is cast with reinforced concrete for locking a mouth, etc; the construction sequence of excavating the drilled shaft comprises that: a raise-boring machine drills a guide hole of phi 216 millimeters from top to bottom; the raise-boring machine enlarges and excavates a small guide well of phi 1, 400 millimeters; a slag slipping guide well of phi 2, 500 millimeters is enlarged and excavated manually from bottom to top; and the slag slipping guide well is enlarged and excavated from top to bottom. The slag slipping guide well is excavated by manual drilling and blasting; slag is naturally slipped and mechanically loaded in the bottom of the well; a large well is enlarged and excavated through drilling and blasting by a manual air drill; and the skimmed slag in a hydraulic backhoe well slips to the bottom of a passage through the slag slipping guide well and is mechanically loaded in the bottom of the well. The construction method has the characteristics of having reasonable construction arrangement, alternately and simultaneously carrying out a plurality of construction types and saving the construction period.

Description

technical field [0001] The invention relates to a civil engineering construction method of a hydropower station, in particular to a construction method for a vertical shaft of a surge chamber of a hydropower station. Background technique [0002] The surge chamber project of a hydropower station has a water chamber-type circular section. The excavation diameter of the vertical shaft is large (≥20m), and the well depth section is long (well depth ≥50m). Under the geological conditions of low strength, medium or above aquitard, and poor well completion conditions, it is difficult to organize the construction according to the general construction plan, and it will prolong the construction period, which will affect the realization of the overall project progress target of the hydropower station. Contents of the invention [0003] The object of the present invention is to provide a construction method for a surge chamber shaft of a hydropower station under weak rock geological ...

AI Technical Summary

Problems solved by technology

[0002] The surge chamber project of a hydropower station has a water chamber-type circular section. The excavation diameter of the vertical shaft is large (≥20m), and the well depth section is long (well depth ≥50m). Under the geological conditions of low strength, medium or higher permeable layers, and poor well completion conditions, it is difficult to organize construction according to the general construction plan, and it will prolong the construction period, which will affect the realization of the overall project progress target of the hydropower station

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