Nuclear magnetic resonance curve-based saturated and unsaturated soil permeability coefficient prediction method

Abstract

The invention provides a nuclear magnetic resonance curve-based saturated and unsaturated soil permeability coefficient prediction method. A permeability experiment and a nuclear magnetic resonance experiment are combined to calibrate a saturated soil permeability proportional constant kc, and prediction of a saturated soil permeability coefficient by using a saturated soil T2 distribution curve is realized; prediction on unsaturated permeability coefficients of a soil body in different water content states requires nuclear magnetic resonance experiments to be carried out on the soil body in the water content states respectively, the relative permeability coefficient in the state is predicted by using the soil sample T2 distribution curve in a certain state, and further, the prediction value of the unsaturated permeability coefficient is obtained. Besides, the invention also provides a processing method when missing order happens to the T2 distribution curve, thereby improving the prediction precision. The scheme provided by the invention can overcome consumption of manpower and materials and a large amount of time generated when the experiment directly measures saturated and unsaturated soil permeability coefficients, and overcome the defects that the existing permeability coefficient prediction method mainly focuses on an experience method and the prediction precision is low.

Description

technical field [0001] The invention belongs to the technical field of saturated soil and unsaturated soil permeability coefficient research in geotechnical engineering, in particular to a method for predicting saturated and unsaturated soil permeability coefficients based on nuclear magnetic resonance curves. Background technique [0002] There are closed air bubbles in unsaturated soil, which makes water need to bypass the air bubbles in the process of infiltration in the soil, which increases the curvature of the water flow in the soil, which makes the seepage in unsaturated soil very slow and difficult to measure. And with the difference of void ratio and saturation, the permeability coefficient of unsaturated soil changes drastically. Due to the time-consuming and labor-intensive method of measuring the permeability coefficient of unsaturated soil, researchers have proposed many indirect prediction models from the perspective of microscopic pores or by analyzing the rel...

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Problems solved by technology

[0003] The purpose of the present invention is exactly to the deficiency of above-mentioned technology, provides a kind of saturated and unsaturated soil permeability coefficient prediction method based on nuclear magnetic resonance curve, overcomes the shortcoming that existing permeability coefficient prediction method is based on empirical method and prediction accuracy is low , to realize the prediction of the saturated soil permeability coefficient of any dry density soil sample and the unsaturated soil permeability coefficient of any water content by using nuclear magnetic resonance test

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