Применение экспресс-методов для определения характеристик насыпных грунтов

Abstract

The main controlled parameter in the production of bases is the compaction ratio; however, deformation characteristics are important for the prognosis of bases settlement. The aim of the research is to determine the relation between the monitored parameters at the construction site and the characteristics used in the design of the foundations, which will allow a quick and effective control of the quality, as well as a prediction of the settlement of fill soils. There are various methods aimed at an express control of the density of fill soils. One of them is the impact stamping method with the help of a dynamic densitometer. The problem of investigating the applicability of this method in industrial and civil construction is relevant. This paper presents the results of experimental studies aimed at assessing the applicability of the DPG-1.2 to control the deformation characteristics of fill soils. The research was carried out in the laboratory conditions of Construction Production and Geotechnics Department of Perm National Research Polytechnic University. The compaction ratio and soil moisture were accepted as the controlled parameters. As the measured parameters, we accepted the compression modulus of deformation, the dynamic modulus of elasticity, force and settlement. The subject of investigation is uniform coarse sand with a maximum density of 1.74 kg/m3 and an optimum moisture content of 14 %. 18 series of tests were carried out with different coefficients of compaction at a constant humidity. Based on the results of the experimental studies, the dependencies were obtained, i.e. the dependence of the compression modulus of deformation, the dynamic modulus of elasticity, and the plastic precipitation on the coefficient of compaction; dependence of the impact force on the plastic settlement. Also, additional experiments were carried out to determine the depth of the compressible strata from the impact load. The obtained dependences were analyzed from the point of the effect of the compaction ratio on the deformation characteristics, as well as the determination of the applicability limits of the dynamic densitometer during the layerwise control of the fill soil compaction.