分离式隧道非同步开挖两洞相互影响程度研究

侧压力系数和隧道净距是分离式隧道非同步开挖时两洞间两个重要影响参数．为探讨不同侧压力系数和隧道净距对分离式隧道左、右洞不同步开挖时两洞间的影响程度,使用有限元方法进行了一系列的计算分析,并通过现场动态监控量测来验证数值模拟的正确性．结果表明:侧压力系数越大、两洞间净距越小,相邻隧道的影响程度越大．最后基于分析结果提出一些关于隧道非同步开挖的建议．

Study of mutual influence degree of two separated tunnels excavated non-synchronously

For two separated tunnels there existed certain influence necessarily when they were excavated non-synchronously. Lateral-stress coefficient and clear distance between two tunnels are two key factors. In order to investigate the influence of different lateral-stress coefficient and tunnel clear distance on two tunnels mutually when they were excavated non-synchronously, a series of calculations and analyses are carried out by using the analysis of FEM. Through the in-situ dynamic measurements, the results of FEM are proved. Through these analysis, some conclusions are drawn. First, owing to excavation non-synchronously, maximum principal stress of cells on the coping and bottom reduces and the maximum principal stress of cells on the both sides increases. Second, the reduced degree of maximum principal stress of cells on the coping and bottom is larger than the increscent degree of maximum principal stress of cells on the both sides with the increment of lateral-stress coefficient. Based on the analytic results some suggestions on excavation of tunnel are put forward in the end.