Study on the Influence of Backward Tunnel Construction on Forward Tunnel in Loess Tunnel with Small Interval
The construction of the backward tunnel with small clear distance will have a great influence on the stability of surrounding rock and the stress of the lining structure of the forward tunnel.If it is not handled properly in the construction,the inverted arch of the forward tunnel may crack.In this paper,taking a shallow-buried loess tunnel with small clear distance introduced by Zhonglan Passenger Dedicated Line into Lanzhou Hub as an example,the influence of the excavation of the backward tunnel of the loess tunnel with small clear distance on the stability of the surrounding rock and lining structure of the forward tunnel is studied by numerical simulation.The results show that the excavation of the backward tunnel of shallow-buried loess tunnel with small clear distance will cause secondary disturbance to the surrounding rock of the forward tunnel,increase the vault settlement and inverted arch uplift displacement of the forward tunnel,and then affect the stability and safety of the tunnel structure.It will make the plastic zone of the middle rock pillar overlap and penetrate,and then cause the relative displacement of the middle rock pillar to increase;the shear stress at the inverted arch of the leading tunnel is concentrated,which leads to the cracking of the inverted arch of the leading tunnel;aiming at the problem of inverted arch cracking in the first tunnel,the corresponding reinforcement suggestions are put forward in combination with the field engineering experience.
small clear distancetunnelnumerical simulationsurrounding rock stabilityinverted arch cracking
NETL
NSTL
万方数据
维普
