Study on the Change Rule of Optimal Overburden Thickness in Multi-cavity Parallel Submarine Tunnels
Submarine tunnel plays an important role in China's land transportation system,and tun-nel construction often adopts the multi-cavity parallel form.The corresponding tunnel water influx problem cannot be ignored,and the optimal thickness of the overburden can be determined by combining with the change of water influx.The combination of theoretical analysis and numerical simulation meth-od was used to analyze the optimal change rule of the overburden thickness for the submarine tunnel multi-cavity parallel working conditions from the perspective of the minimum influx of water.The research results show that with the increase of overburden thickness,the water influx shows a law of"first decrease and then increase",and the minimum water influx is the optimal overburden thickness;The optimal overburden thickness increases with the depth of seawater and tunnel radius;The existence of the pressure relief effect between the multi-cavity parallel tunnel is the main factor affecting the change of the optimal overburden thickness;In two-hole tunnel,the pressure relief effect decreases with the increase of tunnel spacing,and the optimal overburden thickness decreases with the decrease of pres-sure relief effect;In three-hole tunnel,the pressure relief effect of the service tunnel increases with the increase of the ratio of the service tunnel to the radius of the main tunnel,and the optimal overburden thickness increases with the increase of pressure relief effect.The relevant study can provide corre-sponding reference for the design of overburden thickness under the multi-cavity parallel of submarine tunnels.
万方数据
维普
