矿山法隧道近距离下穿既有高速铁路隧道模拟分析

Simulation and analysis of mining method tunnel closely underneath crossing existing high-speed railway tunnel

以深汕铁路塘朗山隧道民乐斜井施工为背景,对铁路隧道辅助坑道近距离下穿既有厦深铁路梅林隧道的施工过程进行了三维仿真数值模拟。塘朗山隧道民乐斜井为无轨运输双车道马蹄形断面,高度约7m,跨度约8.6m。民乐斜井下穿梅林隧道段落采用无仰供的复合式衬砌。厦深铁路为300~350km/h客运专线,隧道变形控制标准为10mm,对民乐斜井近距离下穿施工提出了较高要求。数值模拟的计算结果表明:(1)塘朗山隧道民乐斜井施工过程中,上部梅林隧道发生变形现象,最大竖向沉降为0.177mm(2)塘朗山隧道民乐斜井施工前后梅林隧道衬砌结构的内力变化值数量级较小,引起的应力变化远小于相关要求容许值(3)对既有隧道采取一定保护措施后,既有隧道的变形及内力变化能够满足国家和地区相关规范的变形及安全控制要求。

Based on the construction of the Minle inclined shaft in the Tanglangshan Tunnel of the Shenshan Railway,a three-dimensional numerical simulation of the construction process of the railway auxiliary tunnel passing through the existing Meilin Tunnel of the Xiamen-Shenzhen Railway is carried out.The Minle inclined shaft of Tanglangshan Tunnel is a twolane horseshoe-shaped section for trackless transportation,with a height of about 7m and a span of about 8.6m.The section of the Minle Inclined Shaft passing through the Meilin Tunnel adopts a composite lining without an overhead supply.The Xiamen-Shenzhen Railway is a 300-350km/h passenger dedicated line,and the tunnel deformation control standard is 10mm,which puts forward higher requirements for the short-distance down-penetration construction of the Minle inclined shaft.The numerical simulation results show that:(1)During the construction of the Minle inclined shaft in Tanglangshan Tunnel,the upper Meilin tunnel is deformed,and the maximum vertical settlement is 0.177mm.(2)The lining of Meilin Tunnel before and after the construction of the Minle inclined shaft in Tanglangshan Tunnel The magnitude of the change in internal force of the structure is small,and the change in stress is much smaller than the allowable value of relevant requirements(3)After taking certain protection measures for the existing tunnel,the deformation and internal force change of the existing tunnel can meet the deformation and Security Control Requirements.