DETERMINATION OF THE IMPACT ZONE OF ENABLING WORKS OF A NEW CONSTRUCTION ON THE SURROUNDING BUILDINGS

Abstract

For modern urban construction in the compacted conditions of new sites, the question of the stability of soil massifs under existing buildings is relevant. The intensity of development of possible deformations largely depends on the mutual location of the base of the previously erected foundation and the pit for the new building. The article provides a methodology for determining the area of influence of the pit on the soil foundations of adjacent buildings, depending on the type of enclosing structures and the depth of the pit used. The impact zone was calculated for the pit using protective structures in the form of Larsen sheet piles, bored piles and a diaphragm wall. Corresponding zones of influence of a pit excavated to different depths using different types of pit construction are graphically determined. The scientific result can be explained by the fact that the idealized model of the influence zone takes into account the conditions under which the boundary of the influence zone of a new building can be limited to a distance at which the calculated value of additional subsidence of the soil massif or the base of the existing structure of the surrounding building does not exceed 1 mm. The dimensions of the influence zones are determined at different pit depths, which roughly correspond to the location of the one-, two-, and three-level underground structures of the building. Increasing the depth of the pit to two underground floors increases the zone of influence by 24-31% for the considered types of pit enclosure, and up to three floors - by 14-17%. It was established that the nature of the change in the zone of influence is similar for different types of enclosure structures, and the transition from rigid to flexible functioning of the pit enclosure depends on the ratio of the enclosure's rigidity and the excavation depth. As a practical result of the research, it can be used when choosing the type of construction of the pit to prevent the negative impact of the construction works of the new construction on the surrounding buildings. Keywords: underground construction, pit, concrete, piles, impact, modeling, optimization, parameters