Obstruction testing method for soil permeability under constant flow velocity

Abstract

The invention relates to an obstruction testing method for soil permeability under constant flow velocity. An apparatus for obstruction testing of soil permeability under constant flow velocity is arranged and comprises a cylindrical permeation column, differential pressure sensors, a constant flow pump, a magnetic stirrer, a laser particle analyzer, an inflow water reservoir vessel, valves, pressure-resistant flexible pipes, an effluent water collection container, etc. Obstruction particles are added into the inflow water reservoir vessel and uniformly stirred by using the magnetic stirrer, so an obstruction sample is allowed to be suspended in an infiltration liquid; the constant flow pump is used for maintaining constant seepage flow and continuously supplying water; and the differential pressure sensors are used for replacing traditional piezometric tube in measurement of seepage pressure at a plurality of different seepage sections and automatically and continuously acquiring testing data. The method visually reflects rules that how the particle sizes and quantity of the obstruction particles and seepage time change seepage pressure and permeability of the sample, can change the particle size of the obstruction sample and the content of the obstruction sample in the infiltration liquid, and is capable of carrying out continuous obstruction testing of permeability under different flow velocities so as to research influence of particle migration on the permeability of soil.

Description

technical field [0001] The invention relates to a test method for seepage blockage of soil under the condition of constant flow velocity, in particular to a test method for simulating the effect of soil particle migration and blockage effect on the permeability of soil during the infiltration process. Background technique [0002] In recent years, slope geological disasters such as landslides and debris flows have occurred frequently. The study of the permeability of slope soil is of great significance to the stability analysis of slopes and the study of slope disaster mechanisms. The slope soil permeability coefficient is an important index reflecting the slope soil permeability, which can generally be measured through field and laboratory tests. Most of the current tests use pure water as the seepage medium to measure the soil permeability coefficient. In the actual process, the water flow will carry fine soil particles, which will affect the permeability of the soil durin...

AI Technical Summary

Problems solved by technology

Most of the current tests use pure water as the seepage medium to measure the soil permeability coefficient. In the actual process, the water flow will carry fine soil particles, which will affect the permeability of the soil during the seepage process, especially for those with strong dispersion or resistance. The slope soil with poor erosion ability has a high concentration of fine-grained substances in the water flow, and the error of the soil permeability coefficient measured by pure water in the laboratory is relatively large, which will affect the slope seepage analysis and its performance. Results of Stability Analysis

[0003] At present, the commonly used indoor instruments for measuring the soil permeability coefficient have a small inner diameter, and the applicable soil particle size range is small, and it cannot simulate and quantitatively evaluate the situation that the soil pores are blocked by the fine particles carried by the water flow, and it is difficult to reflect the actual situation.

[0004] At present, the instruments used to measure the permeability of soil indoors usually use constant head test or variable head test. The seepage flow rate of water in the soil is generally calculated, but when the water contains fine particles, the pores of the soil body will be blocked and the seepage flow rate will be reduced.

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