EXPERIENCE IN STRENGTHENING UNDERGROUND PEDESTRIAN CROSSINGS IN WATER-SATURATED CITY SOILS

Abstract

Purpose: to analyze the problem of subsidence of vertical and horizontal elements of underground pedestrian crossings in the conditions of the city of Kyiv (Intersection of Mineralna – Ukrainian streets) taking into account the water-logged structure of the soil. Find a modern solution to this problem using a scientific approach. Using the example of an underground pedestrian crossing, identify the most deformed areas in the elements of the joints of vertical and horizontal structures for further processing and drawing a conclusion for the elimination of similar ones in the future.Methodology: in order to establish the reasons that caused the deformation of structures, to solve the task of engineering survey of the technical condition of their reinforced concrete structures with an instrumental survey of the actual strength, geometry and monitoring of uneven precipitation. Based on the results of field and chamber work, a complex ofstrengthening and restoration engineering and technical measures was developed and recommended to the customer for implementation, taking into account the requirements. Originality: the article provides an example of the implementation of the construction of the foundations of underground pedestrian crossings erected on water-saturated soils in complex engineering and geological conditions using construction water subsidence, usingtechnological methods, with the aim of excluding uneven deformations of foundation sediments above the zones of depression funnels from water subsidence or artificial foundations from vertical cement-soil reinforcing elements, the frontal part of which must be wrapped in reliable base soils.Findings and practical implications. The sealing of horizontal and vertical technological and sedimentary-temperature seams in the construction of foundations, walls and the covering of underground structures should be carried out using modern types of hydraulic plugs that perceive the hydraulic pressure from underground water and exhibit the property of swelling when in contact with flooding water. Such technological solutions can be used in the construction of underground pedestrian crossings in the conditions of dense urban development, in the presence of significant possible vertical deformations in water-saturated soils.Keywords: subsidence, sediment, crack, depression curve, mountain pressure, waterproofing, pile, cement-soil reinforcing element, monitoring