CENTRIFUGE MODEL TEST FOR EVALUATION OF EARTH PRESSURE ACTING ON ADJACENT SHIELD TUNNELS WITH RECTANGULAR SECTION

Abstract

The objective of this paper is to evaluate the mutual influence of constructing adjacent boxy tunnels in the sandy soil using centrifuge model test. In the case three boxy tunnels are constructed very closely and the center tunnel of these tunnels is first constructed, it is appeared that the average earth pressure acting on the top of the boxy segment is larger than overburden pressure at the same depth if this depth is twice of the width of the boxy segment. But if the depth is 4.8 times larger than the length of the boxy segment, the average pressure is less than overburden pressure.