Surge shaft construction method combining impedance with overflow

Abstract

The invention discloses a surge shaft construction method combining impedance with overflow, which includes that the height of a surge shaft body is determined based on reservoir water level and subjected to be higher than exceptional flood level, the inner diameter D of the shaft body is determined based on stable section area calculated by Thoma criterion, and the thickness of the shaft body wall is determined based on the meeting of concrete anti-crack requirements and axis force bearing requirements; the mouth edge at the top of the surge shaft is made into an arc-shaped overflow weir; an annular stilling pool is constructed around the surge shaft body, the width of the stilling pool is determined according to the nappe length Ld of falling water during the overflow of the surge shaft, the altitude of the stilling pool bottom is the altitude of complete bedrock, and lining protection is performed according to the depth of water in the stilling pool; a sluiceway communicated with the stilling pool is constructed on one side of the stilling pool, and the bottom of the stilling pool is excavated to the bedrock surface; a connecting pipe communicated with a water drawing dynamoelectric tunnel is excavated perpendicularly downwards at the bottom of the surge shaft, and consolidation grouting is performed on the periphery; and the diameter of the connecting pipe is determined based on the requirement of an impedance hole. The surge shaft construction method has the advantages that the structure is simple and compact, the project amount is small, and the investment is saved.

Description

technical field [0001] The invention relates to a surge well of a water diversion and power generation tunnel in a hydropower project, in particular to a construction method of a surge well combining impedance and overflow. Background technique [0002] In a hydropower station project, when the unit load changes, it will cause water hammer pressure in the pressure diversion tunnel. In order to reduce the water hammer pressure, make the unit run stably when the load changes, and ensure the quality of power generation, a surge chamber is often built at the junction of the pressurized water diversion tunnel and the pressure pipe. For hydropower stations with long diversion tunnels, if the mountains on both banks are low, the top elevation of the surge tank determined based on the highest surge wave of the surge tank may be much higher than the original ground. In order to reduce the height of the surge well, reduce investment, and at the same time enable the unit to respond qu...

AI Technical Summary

Problems solved by technology

However, due to the large impedance effect, the reflected water hammer wave effect of the surge well will be reduced, resulting in a high penetration rate of the water hammer wave. Therefore, there is a limit to reducing surge waves in the surge well only by setting impedance holes

However, the structure of the traditional overflow surge tank is too complicated due to the need to set up a weir chamber after the top overflows.

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