The results of innovative achievements in the pre-stressed tubular-filled single-drilled piles-foundations construction field are presented. The integrated solution relevance of the scientific and technical problem of developing geotechnical engineering for the considered piles designing efficient structures is shown. For the first time, the physically maximum possible resource carrying capacity of the piles bases under investigation is realized. Geotechnical design of single-hole Simplex piles effective structures allows determining their design dimensions from the bases bearing capacity values equal to the values of critical loads on the pile.

Pile foundations are used to transmit construction loads deep into the ground, thus ensuring the stability of the structure. In this context, there is no question that the calculation of pile bearing capacity is important in the design of economical and safe geotechnical structures. Typically, the axial bearing capacity of piles can be determined using five approaches. At the same time, under real conditions, the effectiveness of these approaches is limited, firstly, by the restrictions inherent in their computational apparatus and, secondly, by the action of a variety of uncertain and random factors. Meanwhile, in geotechnics the uncertainties are largely unknown or very difficult to measure. In view of the above, the aim of the article is to develop a methodology for analyzing the reliability of a pile foundation taking into account uncertainties and partial factors. The methodological basis of the research is a comprehensive approach, which includes the analysis and synthesis of literary data on the topic of work, analytical and experimental research. In the process of research an algorithm based on the Monte-Carlo method and the evolutionary neural network, which allows in the process of calculating the reliability of piles to take into account such uncertainties as: physical, statistical and modeling uncertainties. The conducted tests showed that the model has a high prediction accuracy. The theoretical value of the obtained results consists in the development of the pile foundation reliability evaluation apparatus due to the use of neural network modeling. In practice, the recommendations formulated in the article can be used as a basis for conducting experiments with pile foundations in various soil sciences conditions.

In recent years, due to population growth plans and accelerated economic development, high-rise buildings have become increasingly common in many cities and megapolises around the world. Due to the development of engineering construction, the type and technology of pile footing, which form the basis of such buildings, as well as the control of both single piles and a group of piles, have been significantly improved. At the same time, today the task of adequate assessment of the pile load capacity and justification of effective methods of revealing the reserves of its increase is actualized, because the manufacturing technology is constantly developing, in addition, often the functional purpose of the building itself, the type and intensity of the loads acting on it change. In view of the above, the purpose of the article is to investigate modern scientific- methodological approaches to search for reserves of bored pile load capacity. In order to carry out the study, the article used numerical methods for analyzing the stress-strain state of piles and means of the software package "Plaxis 3D Faundation". In the course of empirical experiments, it was found that the most acceptable results in the load testing of bored piles are given by the Shen method. Besides, the comparison of the results of static probing and static tests with theoretical calculations allowed to reveal the reserves of the actual pile load capacity, and also to determine on what parameters of its installation and characteristics the difference in load capacity depends more: the soil sciences in the pile base, pile diameter, pile length. Theoretical significance of the obtained results lies in the development of methodology for identifying reserves to increase the load capacity of bored piles. Conclusions have practical value that can be used in the process of laying the foundation of high-rise buildings to optimize the number and geometry of pile placement taking into account the reserve of their bearing capacity.

Тольяттинский государственный университет, г. Тольятти, РоссияСтатья посвящена научному обоснованию впервые открытого нелинейно-линейного вида графика зависимости осадки от нагрузки опытной буровой сваи. Показаны теоретические подходы к расчетному определению критических нагрузок по всем пяти зонам состояний предельных равновесий для боковой поверхности ствола и тангенсоида вращения сваи. Представлен расчетный нелинейный график зависимости осадки от нагрузки экспериментальной буровой сваи. Показано теоретическое построение расчетного нелинейно-линейного графика зависимости осадки от нагрузки опытной буровой сваи. Сделаны обобщающие выводы по сущности содержания проведенного исследования.Ключевые слова: теория, эксперимент, грунт, свая, нагрузка, основание, давление, напряжение, сдвиг, деформация, равновесие, зона, осадка, нелинейная и линейная зависимость, тангенсоид вращения. Борозенец Л.М., Ушакова Е.А. Теоретическое обоснование нелинейно-линейного вида графика зависимости осадки от нагрузки экспериментальной буровой сваи 23 Вестник ЮУрГУ. Серия «Строительство и архитектура». 2019. Т. 19, № 2. С. 22-28 Рис. 2. Схема развития зон предельных напряженно-деформированных состояний под тангенсоидом вращения нижнего конца сваи Б-1: 1 -свая; 2 -тангенсоид вращения; 3 -его основание; 4 -задействованные зоны Рис. 3. Схема зон состояний предельных равновесий грунта вокруг ствола сваи: 1 -свая; 2 -грунтонапряженное основание сваи; 3 -границы зон; 4 -задействованные зоны Борозенец Л.М., Ушакова Е.А. Теоретическое обоснование нелинейно-линейного вида графика зависимости осадки от нагрузки экспериментальной буровой сваи 25 Вестник ЮУрГУ. Серия «Строительство и архитектура». 2019. Т. 19, № 2. С. 22-28 Рис. 6. Расчетный график нелинейно-линейной зависимости осадки от нагрузки S = f(Pn): 1 -нелинейный; 2 -линейный