Method for constructing foundation base of junction dam

Abstract

The invention discloses a method for constructing a foundation base of a junction dam. The method includes the steps that weak stratums in directly-bearing stratums of a middle-low water head dam are excavated out, and then the foundation base is excavated according to the burial depth of the middle-low water head dam. A method for determining the burial depth of the middle-low water head dam includes the following steps of a, determining the downstream water depth, the maximum discharge per unit width at the tail end of a protection apron and the upstream-downstream water level difference according to engineering design requirements, and initially calculating the theoretical burial depth of the middle-low water head dam; b, sampling, testing and analyzing bed rock in an area below the dam to obtain the anti-scouring flow speed of the bed rock; c, calculating the maximum scouring depth of the area below the dam in the natural state; d, correcting the theoretical burial depth of the middle-low water head dam according to the scouring depth of the area below the dam, and determining that the burial depth of the middle-low water head dam is the sum of the scouring depth and the theoretical burial depth. The method has the advantages that the scouring depth of the local portion below the dam can be accurate foreseen, the burial depth of a hydraulic structure can be reasonably set, and the service life of a hydroelectric junction project can be prolonged.

Description

technical field [0001] The invention relates to the protection field of medium and low water head dams, in particular to a base construction method of pivotal dams. Background technique [0002] With the increasing number of barrage and dam projects in our country, the problems caused by the construction of hydropower projects have also attracted more and more attention. In hydropower projects with medium and low water heads, there is a certain water level difference between the upstream and downstream water levels, and the discharged water often has a large flow rate and carries a large amount of energy. If these huge energies are not dissipated, they will scour the downstream riverbed and river bank, and most of the coverage of the downstream river section is formed by alluvial, with poor insect resistance, the riverbed will be scoured into pits. When these scoured pits If the location is too close to the hydraulic structure and the pit depth is large, it will cause damag...

AI Technical Summary

Problems solved by technology

In previous studies, in order to simplify the problem, only one or two main factors were considered, and directional research was carried out on a certain aspect. Extensive engineering needs

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