SIMULATION OF THE INFLUENCE OF THE DEVICE OF A DEEP PIT OF COMPLEX SHAPES ON NEARBY LOCATED HOUSES

Abstract

The most common method of constructing an underground space in the tight working space of an existing building is the construction of a foundation pit fence carried out of piles or the diaphragm wall with a gradual excavation of the soil within the fence. At the same time, it is necessary to develop a reliable design of the fence, which guarantees both the absence of loss of stability by the fence and its limited deformations, and the absence of excessive additional deformations and overloading of adjacent structures that put pressure on the surface of the backfill of the retaining wall, the fence of the excavation. In conditions of the tight working space and a complex shape of the fence structure in terms of plan and height, the use of the developed methods for calculating retaining walls in two-dimensional formulation is incorrect, since it does not take into account the effect of the spatial work of the structural elements of the fence.

Methods for spatial modeling of the stress-strain state of a deep excavation fencing with subsequent excavation of soil for the arrangement of the underground part of the future building are proposed. A pit of a non-linear configuration is considered in a site with a complex topography and inhomogeneous layering of soils. The influence of excavation of a foundation pit on the SSS of a number of unfinished existing buildings located nearby has been studied; the phasing of the work has been taken into account.

Modeling was carried out to substantiate effective design solutions for the installation of pile fencing of the excavation and ensuring the stability of the slopes of the open excavation.

The creation of a three-dimensional calculation model in PLAXIS 3D CONNECT Edition V21.01 made it possible to investigate the impact of the construction of the fence and subsequent excavation on existing buildings located in the close proximity of the pit and to obtain deformations and forces in the structure of the fence itself.