Vol 52, No 6 (2016)

A procedure for carrying out and examining the results of experimental studies on reinforced concrete foundations under a superstructure over the entire load interval, up to failure. Conclusions are drawn regarding the comparability of results from experimental studies of punching shear failure in reinforced concrete foundation models at design loads obtained using theory-of-reliability methods.

This paper presents a ground improvement method using sand as material in columnar inclusion. The main focus of the study is to model the consolidation behavior of peat soil reinforced by sand columns. The effects of sand column length and column diameter were determined using numerical analysis. It was revealed that the final settlement strongly depends on the area replacement ratio. The numerical results showed that the installation of larger-diameter, fully penetrated columns reduced soil settlement. The settlement reduction results of our numerical analysis are in good agreement with the experimental results. In order to improve the confining stresses of sand, an alternative approach utilizing geogrid encasement was examined numerically. The increasing stiffness of geogrid effectively increased the load carrying capacity of the sand column. Based on the results, geogrid performs better in smaller-diameter columns.

A method is proposed for determining the load-bearing capability of drilled piles depending on the effects of upward or downward loading. The validity of the method is confirmed by analysis.

Regressive analysis was used to determine empirical correlations between the velocity of an elastic P-wave (compressional pulse) and a number of physical, strength, and deformation characteristics of limestone rock collected at quarries in Turkey. The results may be used to determine the properties of limestone rock formations for engineering purposes.

A technical approach is proposed for studying natural stratiform composite systems, consisting in the integrated analysis of the structure of natural formations and the deformability of specimens under triaxial compression. A comparison was made between experimental results and calculations following from the theory of composites. A semi-empirical dependence is proposed that describes rock deformability under various volumetric component ratios.

A method for the simultaneous calculation of three rotational components using available translational motion accelerograms is examined, allowing a universal analytical relationship to be obtained between Fourier coefficients for rotational and translational motion. The method has been implemented in Eurosoft Odyssey software (published by JSC Eurosoft) and verified by carrying out seismic calculations at the Kurchenko Central Scientific-Research Institute of Structural Engineering.

The problem of experimentally determining design soil characteristics was examined in the course of considering an article by A. V. Pilyagin [1]. A formula is proposed for linking field and compression moduli of overall soil deformation.