Seepage deformation test method for hydropower station dam coastal construction soft rock zone

Abstract

The invention relates to a seepage deformation test method for the dam body seacoast structure weak rock zone of a hydropower station, which is characterized in that holes are dilled on exposed faultage and the fracture zones thereof, then pressurized-water test is performed on positions where seepage deformation is possible to be caused, operators increase the water pressure gradually, observe and measure the seepage discharge beside the dam body faultage, adopt a water sample for simple analysis of water quality, measure the mud content of the water, and also directly observe the condition of the faultage and the fracture zones thereof to further measure the needed test data. The method greatly increases the water pressure value, improves the hydraulic slope of the structure weak rock zone in a test zone and facilitates the observation of a seepage zone and data acquisition for the conditions such as water discharge, water color, water quality change and mud content change, the argillization and softening conditions of faultage zone substances, the destructional forms of the faultage zone, and the like. Through the field data, the invention can quantificationally confirm critical hydraulic slope caused by seepage deformation damage and damage hydraulic slope which are generated in fracture zones of faultages.

Description

technical field [0001] The invention relates to the technical field of hydropower engineering, in particular to a test method for seepage deformation of a weak rock zone along the coast of a hydropower dam body. Background technique [0002] my country's hydropower development is entering a high-speed development stage. A large number of large, medium and small hydropower stations are being constructed one after another, and some of the development projects have poor engineering geological conditions. For example, there are weak rock belts in the coastal structure of the dam body of the hydropower station, sometimes running through the rockfill dam foundation, mainly composed of dam body faults and a series of secondary structural planes, and the main materials of the fault belts are quartz cataclastite, mylonite and breccia , The granite in the fault-affected zone is strongly altered, the structural plane is developed, and the rock mass is broken, most of which belong to th...

AI Technical Summary

Problems solved by technology

If the hydropower station is completed, the reservoir may be damaged by seepage in the weak structural rock belt along the coast. On the one hand, it will endanger the safety of the dam body, and on the other hand, the reservoir may lose part of its benefits, which will directly affect the benefits of power generation.

[0003] Previously, seepage deformation tests on fault zones have been carried out in a few hydropower stations in China, but the results are not very satisfactory

On the one hand, because the water pressure is not easy to simulate or the observation point is not easy to implement, it can only be limited to a low head pressure, which cannot reach the water pressure of a large reservoir. In addition, the observation point generally chooses borehole observation, which has great limitations

Secondly, the problem of test results detection is not solved. Due to various reasons, some tests can only observe the seepage flow of the fault zone, and some have not conducted a comprehensive test on the seepage flow, and the effect is not very satisfactory.

Images