ASSESSMENT OF ASH-STORAGE COOLECTOR STABILITY USING GEOSYNTHETIC REINFORCEMENT ELEMENTS BY TRAY TESTING AND NUMERICAL MODELING

Abstract

The paper presents the results of the assessment of the stability of the embankment represented by ash storage collector (ASC) located on the territory of the thermal power plant of TPP1, metallurgical plant in Temirtau (Kazakhstan). The purpose of the study was to assess the effect of reinforcement elements on the overall stability of the embankment, based on comparisons of the stress-strain state of reinforced and unreinforced embankments. The technological solution for embankment reinforcement was the use of synthetic polypropylene geogrid. Model tray tests as well as numerical simulations by the finite element method were used in the studies. The tray tests were performed at a scale of 1:30, using equivalent materials selected on the basis of the law of dynamic similarity. Based on the results of the tray tests, functional dependencies characterizing the change in the deformation state of the embankment from the increment of a given displacement were obtained. The obtained dependencies show the deformations (vertical, horizontal and resultant) of different locations from the soil base near the source of the given displacement, through the slope to the embankment crest. Similar dependencies were obtained from numerical reinforcement results. Both studies present comparisons of the deformed states of the unreinforced and reinforced models, from which the effect of the reinforcement elements on the overall stability of the embankment is evaluated. Comparisons of the results of tray tests and numerical simulations are presented. The comparisons are represented by corrective actions, which are expressed by dependencies between the values of ratio coefficients and the distance from the source of a given displacement. The ratio coefficients, in turn, reflect the quantitative difference in the deformed state of the unreinforced from the reinforced embankment. The obtained results make it possible to evaluate the overall stability of the ASC embankment by express numerical simulation, the quality of which will be improved by the introduction of corrective actions obtained on the basis of model, but still insitu tests.