ANALYSIS OF DEFORMED STATE STRUCTURES KIEV SUBWAY TUNNELS ON AN AREA OF TRANSITION FROM SPONDYLOV’S CLAY TO BUCHATSKIY SANDS

Abstract

Purpose. The considerable deformations of construction of running and station tunnels on the area of substantial change of engineering and geological terms may be arise. It is necessary to expose the reason of development of deformations, to develop the ways of its minimization and on the basis of design and calculations and to find out possibility of change of axis to the tunnel relatively to the engineering-geological terms. Methodology. For the decision of the deformed state analysis problem of the system «construction-array» the numeral analysis by using the finite element method (FEM) is conducted. On the basis of the got results the graphs are built and dependences of tunnels support deformation at the substantial change of engineering and geological terms are established. Findings. The presence of the weak watersatured soils in tray part of tunnels at the substantial change of engineering-geological terms causes the increase of deformations of tunnels construction, and also vibrodeformations in the ground bases. In addition, the change of physical and mechanical characteristics of soilswithin the limits of support of tunnels considerably influences on the level of the supports deformed state. The improvement of the deformed state of tunnels support on the areas of change of soils characteristics surrounding array (especially lay of support) can be attained by the chemical fixing of weak soils or common change of tunnelaxis in a plan and profile in order to maximally use durability and stability of soil layer with biggest deformation characteristics. The choice of decision from two resulted variants of increase of operating characteristics of running tunnel support of his durability and decreasing of between repair terms follows to ground with bringing in ofeconomic calculations. Originality. The principal reason of considerable deformations on the area of transition from clays to sands is exposed, that is explained by the phenomenon of the watersatured base vibrodeformations under a tunnel. Practical value. Offered approaches on diminishment of deformations at building of running tunnels of Kievunderground passage at the substantial change of engineering and geological terms.