Non-Destructive Time-Domain Reflection for In-Situ Loess Collapsibility
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Solution Overview
Problem
Existing methods for evaluating loess collapsibility, such as indoor and field tests, are time-consuming, costly, and disruptive to the soil structure, lacking a rapid and non-destructive assessment method.
Innovation Solution
An in-situ evaluation method using non-destructive time-domain reflection technology to measure dielectric constant and conductivity, calculating dry density and mass water content, and applying a mathematical model to determine collapsibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If indoor test methods are used to evaluate loess collapsibility, then measurement precision can be achieved, but loss of time increases significantly due to the 24-hour stabilization requirement for each load level
Solution Approach 1:
The patent replaces the mechanical compression testing system with an electromagnetic wave-based detection system. Instead of applying mechanical loads and waiting for stabilization, the system uses time-domain reflection technology to detect dielectric constant changes, which correlate with moisture content and collapsibility. This substitution eliminates the time-consuming mechanical compression process while maintaining evaluation accuracy.
Solution Approach 2:
The patent changes the measurement parameter from mechanical settlement under load to dielectric constant. By measuring the dielectric constant at different moisture levels and correlating it with collapsibility coefficients, the method achieves accurate evaluation without requiring the time-intensive mechanical compression and stabilization process.
2Reliability
If field test methods such as static load test and test pit immersion test are used, then reliability of collapsibility evaluation is improved, but device complexity and cost increase due to the need for test sites and complex equipment
Solution Approach 1:
The patent replaces complex mechanical testing equipment and test pit structures with a portable electromagnetic detection system. The time-domain reflection instrument can be easily deployed without constructing test pits or setting up complex loading devices, significantly reducing device complexity while maintaining reliable collapsibility evaluation through dielectric constant measurements.
3Measurement precision
If indoor test methods are used to obtain undisturbed loess samples, then measurement precision can be achieved, but loss of substance occurs due to structural damage during sampling and transport
Solution Approach 1:
The patent replaces mechanical sampling and physical sample handling with a non-contact or minimal-contact electromagnetic detection method. The time-domain reflection technology measures dielectric constants in situ without requiring extraction, transport, or preparation of physical samples, thereby completely avoiding structural damage and sample degradation.
4Loss of information
If conventional evaluation methods are used, then comprehensive data can be obtained, but productivity decreases due to the time-consuming nature of sample collection, testing, and analysis
Solution Approach 1:
The patent changes the measurement approach from multi-step mechanical testing to direct dielectric constant measurement. By measuring dielectric constants at different moisture levels and using established correlations with collapsibility coefficients, the system obtains comprehensive evaluation data instantly without the sequential time-consuming steps of sample collection, preparation, compression testing, and analysis.
Solution Approach 2:
The patent enables continuous measurement of dielectric constants without interruption for sample preparation or equipment reconfiguration. The electromagnetic detection can be performed in situ at multiple locations and depths continuously, maintaining productive workflow while gathering comprehensive data for collapsibility evaluation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Provides a fast, non-destructive, and cost-effective method to assess loess collapsibility, distinguishing between strong, moderate, and slight collapsibility with high accuracy and reliability.
Implementation Method 1
testing a time-domain reflection waveform diagram of the undisturbed loess at the site layout point through non-destructive time-domain reflection technology
Implementation Method 2
obtaining the dielectric constant and conductivity of the undisturbed loess at the layout point according to the time-domain reflection waveform diagram
Data Source
AI summary
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.