Bikus K. The influence of piles preloading on their settlement reduction

The object of investigation is piles soil basement and piles foundation, the development process of piles preloading on their settlement reduction. The aim of thesis is to improve the method related to pile preloading, taking into consideration Ukraine's engineering and geological conditions. Methods of investigation: static piles tests on location; the method of finite elements for modeling the strained and deformed state of foundation under static pile loading; asymptotic methods in order to define axial and strain along piles length; analytic methods for comparison the calculation results with on location tests results and theoretical investigations of other scientists. Theoretical and practical results: the asymptotic method to define differentially contact and axial strain along piles length and under its heel in multilayer soil base has been improved; the use of this method helps to dispose piles rationally and use effectively the reserves of piles bearing capacity; the method of piles rational displacement with its preloading taking in consideration engineering and geological conditions of region has been improved (the use of this method in a process of designing makes possible increase the number of stories in building and decrease the number of piles or their geometric parameters); applying documents for invention of Ukraine have been worked out; a patent for invention for improved field method of differential assessment resistance along side surface and under pile heel resistance has been taken out. Scientific novelty: new field results of influence of loading piles on cutting and leveling their setting have been obtained; it makes possible to increase loading on piles till 25%; the method of numerical modeling of step by step loading, unloading and repeated loading of pile by means of parameters identification of elastic soil model and coefficient of side pressure; for the first time by means of numerical modeling the transferring effect of nonconnected with pile slab grillage and with loosen soil under piles heel has been elucidated; it means the dependence of pile setting on slab setting till 70%;the asymptotic method to calculate and design pile foundation making possible to determine optimal dependence between pile length and distance between them has been worked out. Applications: the foundation and its structural elements for housing complex in Dnipropetrovs'k have been designed; economic effect equals 1224,909 gr; the results of research have been introduced in a manual on designing and arrangement of piles and also in educational process of Pridneprovsk State Academy of Civil Engineering and Architecture. Sphere of application: residential and industrial construction.