Abstract:

In this paper, the feasibility and safety of construction scheme for intersection between mined tunnel on Line No. 8 of East Bid Section of Red Line light rail in Israel and Em Hamshavot Station with an sharp angle of 12° are studied; and then the stability of the connection section, diaphragm wall, irregular Cshaped crosssection and retaining wall of adjacent Road No.4 is studied and analyzed by 3D finite element software and stiffness equivalent theory. The analytical results show that: 1) The displacement calculated by finite element method is smaller than the monitoring date; and the monitoring date is smaller than the allowable values of structure. 2) The pile foundation of the retaining wall is greatly affected by tunnel excavation; but the maximum tensile stress of the pile foundation is still in the range of concrete tensile strength. 3) For the intersection between soil and wall beam, the maximum compressive strength caused by the soil is 0.84 MPa; and the maximum shear stress is 0.29 MPa, which exceeds the cohesion stress (40 kPa); it shows that the interaction should be balanced by crossbrace. 4) The increased compressive stress of diaphragm wall at tunnel portal caused by tunnel excavation is large and still within the range of the concrete compressive strength. 5) The tensile stress of the wall beam exceeds the tensile strength of concrete, but the reinforcement required to provide tensile stress is much less than the actual reinforcement of the wall beam.

Key words: tunnel constructed by mining method, Cshaped crosssection, diaphragm wall, wall beam, compressive strength, tensile strength