Abstract: An in-situ evaluation method and system for loess collapsibility based on non-destructive time-domain reflection technology, includes: calculating loess dry density and mass water content; considering loess dry density, mass water content and basic physical property indicators, and evaluating loess collapsibility in situ through mathematical models. The loess collapsibility in-situ evaluation method based on the non-destructive time domain reflectometry technology of the present invention can not only realize whether the loess has collapsibility, but also has the potential to distinguish strong, medium and slight collapsibility.

Abstract: The disclosure discloses a cone penetrometer for detecting multi-pollutants and the corresponding method based on laser induced fluorescence (LIF) and time domain reflectometry (TDR). The cone penetrometer includes two main modules: the TDR module mainly composes of a PEEK insulating rod, two gold-coated stainless steel probes and a coaxial cable; the LIF module mainly composes of endoscope image sensor, alumina glass lens, an ultraviolet LED with a 280 nm-wavelength, and an ultraviolet LED with a 325 nm-wavelength. Detection is performed to obtain the soil dielectric constant for characterizing the volumetric water content, electrical conductivity for the content of ionic pollutants, fluorescence intensity at 325 nm-wavelength for the content of polycyclic aromatic hydrocarbons, fluorescence intensity at 280 nm-wavelength for the content of humic acid, and soil images for soil types.

Abstract: A non-invasive time domain reflection probe calibration method includes: using different volume ratio of ethanol and deionized water mixed solution to calculate a test target's medium weight coefficient and waveguide length of the non-invasive time domain reflection probes; using different concentrations of NaCl solutions to calibrate a waveguide geometric dimensioning of the non-invasive time domain reflection probes; preparing compacted soil samples with known different moisture contents and densities, and calibrating a correlation parameter of compacted soil samples' dielectric constant and conductivity with moisture content and density. The method not only determines the sensitivity of the test target medium of the non-invasive time domain reflection probes, but also obtains the waveguide length and geometric dimensioning of the probe, and realizes an accurate test of moisture content and density of the soil.

Abstract: An in-situ evaluation method and system for loess collapsibility based on non-destructive time-domain reflection technology, includes: calculating loess dry density and mass water content; considering loess dry density, mass water content and basic physical property indicators, and evaluating loess collapsibility in situ through mathematical models. The loess collapsibility in-situ evaluation method based on the non-destructive time domain reflectometry technology of the present invention can not only realize whether the loess has collapsibility, but also has the potential to distinguish strong, medium and slight collapsibility.