The dissertation is devoted to the solution of the actual scientific and practical problem of further improvement of the structural solution of retaining walls with a structural surface (RWSS) and methods of their calculations for the purpose of designing and operation of buildings and structures in difficult engineering - geological conditions. For practical calculations, the model of the variable coefficient of rigidity of the base and the calculated resistance for a long loaded base is used, which allows to take into account the features of contact interaction in the conditions of uneven deformations of the base. In a series of experimental studies basic properties of these retaining walls are determined - compaction and increase of bearing capacity of the soil base. Recommendations on the design of retaining walls with structural surfaces have been developed, which can be used to calculate retaining walls with structural surfaces in complex engineering-geological conditions. The most unfavorable variants of realization of reactive pressures are possible at such combinations of deformation and force influences: curvature of convexity of a surface of a basis and the external moment which is directed perpendicularly to the plane of curvature; the curvature of the concavity of the base surface and the external moment directed parallel to the plane of curvature; ledge or failure at the end of the foundation element of the retaining wall and the external moment directed perpendicular to the line of the ledge. Modeling with the help of software PLAXIS allowed to analyze the stress-strain state of retaining walls that interact with the base, which is unevenly deformed (radius of curvature - 1-3 km), according to the calculation schemes for two options: 1 option - angular retaining wall; option 2 - retaining wall with a structural surface. With a slight difference in total displacement within (15-18 %) and uniform subsidence of the retaining wall with structural surface, compared with the retaining wall of the angular type, the whole soil mass was involved, confirming the contact stresses, which are evenly distributed on the surface of the RWSS. Mathematical modeling shows a reduction in stresses on the contact surface up to 15 %. Gradual filling of voids leads to an even distribution of efforts, which in the long run increases the service life of the structure, thus providing an economic effect. The peculiarity of the design solution of RWSS in the interaction of soil with the structural surface increases the bearing capacity of the base due to the formation of elastic cores and unloading vaults. The fifth section develops «Guidelines for the design of retaining walls with a structural surface», which can be used to calculate the RWSS in complex engineering and geological conditions. When designing retaining walls, structural schemes must be adopted that provide the necessary strength, stability and spatial immutability of the structure as a whole, as well as its individual elements at all stages of construction and operation. A clear scope of application of the RWSS was determined, which depends on the engineering and geological conditions of the construction site, purpose and service life of structures, requirements for materials and rules of installation of the RWSS, the basic provisions of the calculation were formed.
The calculation technique, which reflects a new approach to the design of RWSS, taking into account the long-loaded basis, has been experimentally tested. The conducted experimental researches confirm theoretical calculations and testify to the decision in the dissertation work of an actual scientific and practical problem of use of retaining walls with a structural surface in difficult engineering-geological conditions. With the practical implementation of the proposed structures at industrial and civil engineering facilities compared to typical solutions, which are oriented to use in normal conditions, an economic effect of 55.00 thousand was obtained UAH at the device of 10 m/p of a wall.
