Vol.1, No 5, 1998
pp. 645-650
UDC 624.2/.8(045)
DISCRETE MODEL OF TUNNEL
Dušan S. Živković
Civil Engineering Faculty University of Niš,
Niš, 14 Beogradska st. Yugoslavia
Abstract. With discrete models series "C-MONT"
the real technological treatment of doing montage tunnel lining is simulated.
The deep tunnel of a round cross section is observed. The primary state
is considered homogenous and isotropic in the area of discrete model. Rocky
mass is elastic-plastic area which deformity is shown with "work
line". By the result interpretation the connection of tension and deformity
is made with the distance of the front of the excavation, the processing
speed of excavation and by continuity of reological process of the convergency
of the contour of excavation. Attention is paid to the influence of the
value of the final elements, their density in the zones the tension is
concentrated and to the number of integrated points to the accuracy of
calculation as well. Finite elements method and programs for dynamic calculation
of the construction in nonlinear area is applied.
Key words: Tunnel, tunnel lining, underground,
pressures, modeling, tension, deformity
DISKRETNI MODEL TUNELA
Diskretnim modelima serije "C-MONT" simuliran je
realan tehnološki postupak izvođenja montažne obloge tunela.
Posmatra se duboki tunel kružnog poprečnog preseka.
Primarno stanje napona se smatra homogenim i izotropnim u prostoru diskretnog
modela. Stenska masa je elasto-plastična sredina čija je deformabilnost
prikazana "radnom linijom". Interpretacijom rezultata je uspostavljena
veza napona i deformacija sa rastojanjem obloge od čela iskopa, brzinom
napredovanja iskopa, i trajanjem reološkog procesa konvergencije konture
iskopa. Skreće se pažnja na uticaj veličine konačnih elemenata, njihovu
gustinu u zonama u kojima dolazi do koncentracije napona, kao i broj integracionih
tačaka na tačnost proračuna. Korišćen je program za dinamičke proračune
metodom konačnih elemenata u nelinearnoj oblasti. Doprinos rada je u jednoj
novoj definiciji diskretnog modela za numeričku analizu tunelske obloge.
Ključne reči: tunel, obloga, podzemni
pritisak, modeliranje, napon, deformacija
