基于Peck公式铁路隧道下穿既有公路隧道路基沉降规律分析

Analysis of the Regularity of Subgrade Settlement due to Railway Tunnel Underpass of Existing Highway Tunnel Based on Peck Formula

交叉隧道的路基沉降值研究,对道路建设有重要意义。为了定量确定铁路隧道下穿既有公路隧道所引起的既有公路隧道路基沉降规律,结合了盘道岭公路隧道和草莓沟隧道的工程实例,以Peck公式为依据,经理论推导,得到了在交叉隧道近接距离影响下的路基沉降值及其相应解析解。并在此基础上对影响路基沉降的因素进行了探讨。结果表明,既有公路隧道路基沉降的大小与沉降槽宽度系数、内摩擦角、高低倾斜率、隧道近接距离等因素相关。通过Peck计算出的结果与实测数据对照,结果相吻合,表明改进后的路基沉降计算公式能较好地反映出交叉隧道的路基沉降规律。

The study of subgrade settlement for intersected tunnels is of great importance to road construction. In order to quantitatively determine the regularity of existing highway tunnels＇ subgrade settlement caused by the railway tunnels underneath pass the existing highway tunnels. In this paper the Pandaoling Tunnel and Caomeigou Tunnel are taken as engineering background, the value of subgrade settlement and its relevant analytic solutions which influenced by the close-spaced distance of crossing tunnels are obtained after theoretical derivation on the basis of Peck formula. The result shows that, the value of subgrade settlement of existing highway tunnels is related to the factors of width parameters of settlement trough, internal friction angle, high-low inclination rate and tunnel approach distance. The result calculated from Peck formula is coincide with measured data, which indicates that the subgrade settlement calculation formula revised in this paper can better reflect the regularity of subgrade settlement of intersected tunnels.