单线铁路隧道斜切式隧道门模型试验研究

Experimental Research on Bamboo-Truncating Tunnel Portal for Single-Track Railway

采用几何相似比为1∶30的模型对单线铁路隧道斜切式隧道门的2种型式———正斜切式和逆斜切式隧道门进行了相似材料模拟试验,试验考虑了仰坡坡度和隧道门与线路中线夹角的影响.试验结果表明,洞口段围岩压力和结构内力与覆盖层厚度、仰坡坡度和隧道门与线路中线夹角有关———洞门正交时,结构底部仰拱处围岩压力和弯矩最大;洞门斜交时,结构拱腰处弯矩最大.

Model experiments with a geometric similarity ratio of 1∶30 were carried out to investigate the ground pressure and internal force of up and down bamboo-truncating tunnel portals for single-track railway. In these experiments, grade of up-slope and crossing angle between portal and railway center line were considered. The experimental results show that ground pressure and internal force around a tunnel portal are related to the thickness of overburden, the grade and the crossing angle: when the crossing angle is 90°, maximum ground pressure and bend moment are at the invert bottom of a tunnel portal; when the crossing angle is 45°and 60°, maximum bend moment is on the side walls of a tunnel portal.