Load-transfer mechanism in the ground with discontinuity planes during tunnel excavation

불연속면이 존재하는 지반에서 터널굴착에 의한 하중전이

  • 이상덕 (아주대학교 건설교통공학과) ;
  • 변광욱 (아주대학교 건설교통공학과) ;
  • 유건선 (한라대학교 토목공학과)
  • Published : 2002.03.01

Abstract

In this study, the influence of the presence of discontinuity planes on the load transfer mechanism and the pattern of loosening zone was studied based on the laboratory test. The trap-door and the reaction plates are installed as the bottom plane of the model box. The vertical discontinuity plane is installed in the dry sand. Various overburden heights and locations of discontinuity planes are applied as major factors in this study. The results show that at higher overburden heights over about 1.5 times the excavation width, the ratio of the transferred stress to the insitu stress converges to a certain value even if the overburden height increases further. The results also show that the discontinuity plane gives relatively larger influence on the load transfer mechanism, that produces the unsymmetrical load concentration, when the discontinuity plane locates within the tunnel width. When the discontinuity plane locates outside the tunnel width, the unsymmetrical load concentration is reduced considerably.