Дослідження динамічних параметрів ґрунту в лабораторних умовах

Abstract

UK: Представлено методику дослідження динамічних властивостей ґрунтів в умовах одновісного стиснення. Для визначення параметрів динамічної пружності та в’язкості розроблено устаткування на базі стандартного компресійного приладу «КПр–1». Представлені принципи роботи створеного електронного приладдя та високоточних датчиків для автоматичного зняття та реєстрації даних експерименту. Показано, що дослідження ґрунтів при різних швидкостях навантажень дозволяє визначити динамічні параметри в широкому діапазоні навантажень. На прикладі піщаного ґрунту приведені результати експериментів.

EN: Problem definition.Under dynamic load, both rate of change and duration of the load can affect the process of soil deformation. Analysis of dynamic soil parameters can be carried out under uniaxial compression conditions while subjected to the high velocity load at which time soil manifests both viscous and elastic properties. Carrying out such tests in the laboratory environment requires development of the specialized equipment and methods for determining the dynamic parameters of the soil under a wide range of loads.

Purpose.Design and development of the methodology to analyze dynamic soil parameters in the laboratory conditions; construction of the equipment to record changes in the stress–strain state of soil samples under high velocity load with automatic data transfer to a computer system for further analysis.

Analysis of recent research. Numerous authors studied the viscoelastic soil properties in order to analyze the effect of dynamic loads (in particular, seismic loads) on the soil base. Fundamental studies of sandy and clay soils at different strain rates are found in the works by D. D. Barkan, M. D. Krasnikov, P. L. Іvanov and others. Highly specialized mechanical devices have been designed in order to determine dynamic soil parameters. However, those devices utilized overly complex data recording systems, relying on costly manual data processing and requiring special operator skills.

Results.The paper describes underlying principles of the designed electronic device and high–precision sensors for automated data collection and logging of the dynamic viscosity and elasticity soil parameters, based on the standard compression device “KPr–1”. It also shows that the study of soils at various load velocities enables the determination of the dynamic system parameters for a wide range of loads. The results of experiments conducted on sandy soil are presented as an example.

Conclusion. Analysis of the dynamic soil parameters under compression was conducted using the designed data acquisition system, allowing the measurement of shifts and deformations in the soil to be performed with high precision and frequency. The experiments confirmed, that under high velocity load, soil behavior does not follow the Voigt model, but can be accurately described using the Kelvin model.