Finite element evaluation of the effects of faulting on a shallow tunnel in alluvial soil

Abstract

A numerical estimation is presented on the\ud effects induced in an existing tunnel by the development of a\ud fault from the deep bedrock during a seismic event. The\ud spreading of the fault within the alluvial deposit hosting the\ud tunnel, and the consequent effects on its permanent liner, are\ud studied in static conditions through a series of elastic-plastic,\ud plane strain finite element analyses. They account for the\ud reduction of the shear strength and stiffness characteristics\ud of the faulting zone with increasing irreversible strains. Even\ud though the calculations require only ‘‘standard’’, e.g. peak\ud and residual, material parameters it is shown that these\ud properties can hardly be obtained for the alluvial deposit at\ud hand. To overcome this drawback a relatively large scale insitu\ud tests could be performed and its results could be interpreted\ud through a suitable back analysis. This would permit\ud characterizing the numerical model to be subsequently\ud adopted for the analysis of the faulting process

Research on the Mechnical Characteristics of Primary Supports in Guanjiao Tunnel Fault Fracture Zone and its Influence Zone by Field Tests

“…The diseases which are prone to occur are water inrush, collapse and large deformation in fault fracture zone during tunnel construction. In order to avoid these diseases, many scholars studied the tunnels which have been built or are building and provided many successful experiences [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Because of the difference of geological conditions, the past experiences are not applicable to all tunnels.…”