Backfill construction method for vertical shaft cave

Abstract

The invention relates to a backfill construction method for a vertical shaft cave. The invention aims at providing a backfill construction method for the vertical shaft cave to reduce the construction difficulty and improve the engineering safety. The technical scheme adopted by the invention is that the method comprises the steps of: a, excavating a first layer of a vertical shaft on a selected position; b, punching a circle of a pipe roof to a karst cavity of the wall on a position of the bottom part of the first layer vertical shaft; c, clearing deposits inside the karst cavity of the first layer, and backfilling the karst cavity after being cleared with concrete by adopting the pipe roof as a bottom template; d, continuing to excavate the vertical shaft after completing the concrete backfilling to reach the stadium of the concrete, carrying out the construction for the karst cavity disclosed by a second layer according to the steps b and c after reaching the position of the bottom part of the second layer vertical shaft, and backfilling and grouting the top part of the lower concrete layer by utilizing an upper layer pipe roof; and e, repeating the step d until reaching the requirement of the vertical shaft depth. The backfill construction method is applicable to hydraulic and hydro-power engineering and is particularly applicable to the excavation of the vertical shaft in karst regions.

Description

technical field [0001] The invention relates to a construction method for backfilling a shaft karst cave. It is suitable for water conservancy and hydropower projects, especially for the excavation of shafts in soluble rock areas. Background technique [0002] For hydraulic shafts arranged in soluble rock areas, it is inevitable to encounter karst forms that develop vertically along the shaft wall during the excavation process of the shaft. Meters or even hundreds of meters. Hydraulic shafts are often pressurized hydraulic tunnels, and reinforced concrete or steel pipes are generally used as linings, which requires that the karst cavities developed on the shaft walls must be backfilled with concrete. [0003] However, the above-mentioned karst form has caused great construction difficulties for backfilling, especially for filled or half-filled karst caves. In order to obtain sufficient elastic resistance of the surrounding rock, the filling in the karst cavity must be clea...

AI Technical Summary

Problems solved by technology

[0003] However, the above-mentioned karst form has caused great construction difficulties for backfilling, especially for filled or half-filled karst caves. In order to obtain sufficient elastic resistance of the surrounding rock, the filling in the karst cavity must be cleaned and replaced with concrete.

The timing of backfill treatment of karst has become a more critical issue. If the karst is completely exposed before treatment, it will face the construction difficulty of high shaft walls; As the shaft is further excavated, the karst is further exposed. When the accumulation of the karst form in the lower layer is cleaned up, the backfilled concrete foundation of the upper layer will be voided, resulting in instability and accidents.

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