A New Procedure for Construction Metro Station in Non-cemented Soil: A Numerical Investigation

Abstract

According to the development of societies and increase of population, the use of underground spaces has been developed in the past decades. The high cost of construction of the urban space such as metro stations, leads to increase the demand for tunnels in big urban. Thus, an economical method should select to build these structures. One of the popular and flexible underground construction methods is New Austrian Tunneling Method (NATM). When NATM is implemented in big cross section, face is divided in to temporary section. This method includes Central Diaphragm (CD) method, Side wall Drift (SD) method, Pile-Beam-Arch method and etc. In the non-cemented soil, the settlements due to the excavation sequences maybe leads to damage to nearby structures. Therefore, it is necessary to investigate the effective factor of controlling tunnel-induced settlements and change the construction stages during excavation. A lot of numerical studies have been done on NATM in urban areas that often deal with the simulation of tunnels and small sections. In this paper, a number of Finite Difference Method analyses were conducted to evaluate the effects of different patterns for advancing the tunnel face on the settlement in NATM station construction in the non-cementation soil. Constructing a station is considered as a big section. Induced displacements are empirically controlled by adjusting the speed of excavation, installing support and partial-face excavation.