DETERMINATION OF BOUNDARIES PARAMETERS OF THE COMPUTATIONAL MODEL FOR ASSESSING THE IMPACT ON THE SURROUNDING FACILITIES FROM TUNNELING

As a result of active development of Moscow underground space, as well as due to the increased density of urban development, it is necessary to forecast additional displacements of surrounding buildings from new construction in order to prevent emergency situations. For this reason, one of the important directions is mathematical modeling of the additional displacements of the surrounding building after erection. Establishing the parameters of design boundaries of a geotechnical model is one of the factors that greatly influence the results of the simulation. This study deals with the assignment of the lower boundary of the scheme when estimating the impact from tunneling works in a two-dimensional formulation. A review of international experience in simulating the design scheme depth for various geotechnical problems and its comparison with Russian experience in modeling schemes has been made. The deformation marks located on the ground surface in the zone of influence of the Rublevo-Arkhangelskaya and Troitskaya (Kommunarskaya) lines of the Moscow Metro under construction were selected for the analysis. The authors carried out the selection of the lower boundary of the scheme by changing it in proportion to the outer diameter of the tunnels in dispersed and rocky soils. The obtained data were compared with geodetic monitoring one. Calculations were made for three different soil models such as Mohr-Coulomb, Mohr-Coulomb with increasing deformation modulus of the prism under the excavation and Hardening soil. In addition, calculations were made for two cases of assignment of the overburden coefficient - according to normative documentation and available research on the subject. As a result of this work, more than 600 calculated cases were obtained. Based on these cases, recommendations were developed for adjusting the scheme depth for the considered soil models.