Foam as a soil conditioner can transform the mechanical properties of excavated natural muck and lubricate interface between cutting tools muck, thus reducing tools’ wear promoting efficiency earth pressure balance (EPB) shield tunneling. This paper aims to explore meso-mechanism foam in improving workability sand by combining discrete element modeling (DEM) with experimental investigations slu...

Tunnelling through cities underlain by soft soil, commonly associated with soil movement around the tunnels and subsequent surface settlement. The predication of ground movement during the tunnelling and optimum support pressure could be based on analytical, empirical or the numerical methods. The commonly used Earth pressure balance (EPB) tunneling machines, uses the excavated soil in a pressu...

One of the main issues involved during tunnel construction with tunnel boring machines is the tail gap grouting. This gap is between the external diameter of tunnel lining and the excavation boundary that is filled with high-pressure grouting materials. In this work, three different approaches of gap grouting modeling in the FLAC3D software are investigated with a special attention to the...

The visualization system has been developed to control the fluidity of excavated soil in chamber EPB shield real time during advance. For further improvement system, agitation tests fluid sand mixing with CMC aqueous solution as a thickening material or rheological form enhance have carried out clarify its flow property. It was confirmed by that agitating flapper torque decreased increase numbe...

The development and extension of large cities induced a need for shallow tunnel in soft ground of building areas. Estimation of ground settlement caused by the tunnel excavation is important engineering point. In this paper, prediction of surface subsidence caused by tunneling in one section of seventh line of Tehran subway is considered. On the basis of studied geotechnical conditions of the r...

• A load model of shield machine is developed considering the pose. The static characteristics thrust parallel mechanism are studied. new proposed to determine total and grouped thrusts. verified by an engineering case. hydraulic system that emphasizes controlling used for driving forward pose adjustment. To control regulate precisely, it great significance solve thrusts (thrusts different cyli...

Abstract The underground construction is based on effective and rapid building of running tunnels that connect stations. most technique shield-driven tunneling. It the application a tunneling shield, it means, special aggregate excavates ground builds support. Even with fact holds surrounding massif, in weak layered rocks possible formation subsidence trough, namely, significant deformations da...