Tregub O. Improvement of design method of shallow foundations taking into consideration the nonlinearity of soil deformation

The object of research - the peculiarities of the work of shallow foundations at nonlinear dependence of loads on settlements. The purpose of the dissertation is the study of the base at nonlinear dependence of settlements on loads to improve the methods of calculation and design of shallow foundations outside the linear dependence between stresses and strains in soil. Research methods: analysis of the test results from experimental foundations at loads corresponding to nonlinear dependence of settlements on loads; correlation and regression analysis; numerical modeling; probabilistic calculations of bases. Theoretical and practical results: we firstly determined empirical dependence on the nonlinearity parameter of settlements on physical and mechanical characteristics of the soil and the dimensions of foundations, which permitted to improve the method of calculation of the (DBN V.2.1-10-2009) settlements of shallow foundations outside the linear dependence between stress and strain in soil; we developed criteria for reliability of shallow foundations that take into account the heterogeneity of soil characteristics, the probability of excessive settlements considering the nonlinear stage of deformation of the base, inaccuracies of accepted method of calculation of nonlinear settlements, load stability. The improved method permit to design shallow foundations of more rational dimensions through the use of empirical equations which improve the accuracy of the calculation of non-linear settlements and reasonable criteria of reliability of bases. The research results permit to harmonize national standards of Ukraine with the European standards in terms of determining the allowable pressure on the base of shallow foundations. Novelty of the research: for the first time we defined the boundaries of rational application of methods of calculation of nonlinear settlements depending on soil properties and dimensions of shallow foundations; we firstly developed empirical relationships to the method of calculation of settlements of shallow foundations outside the linear relationship between stress and strain in soil; we developed criteria for reliability of bases taking into account the nonlinear dependence of settlements of shallow foundations at loads; we improved methods of calculation and design of shallow foundations taking into consideration the nonlinearity of soil deformation through the development of a method of calculation of nonlinear settlements and determination of allowable pressure on the base. Implementation level: improved design method of shallow foundations taking into consideration the nonlinearity of soil deformation was used at design development of the foundations of a public building in pl. Tcentralna, 2, Slavutych, Kyiv region. The research results are introduced into the learning process in SHEE PSACEA. Range of application: the design of shallow foundations.