论文部分内容阅读
为了研究反压护拱施工对浅埋偏压小净距隧道稳定性的影响,首先介绍了藻溪隧道反压护拱的施工过程,并以此为工程背景,利用FLAC3D有限差分软件模拟了在不同厚度反压护拱下的隧道开挖过程。通过分析围岩位移、应力和塑性区的变化情况,得到了反压护拱厚度对浅埋偏压小净距隧道稳定性的影响规律。结果表明:随着反压护拱厚度的增加,浅埋侧左洞拱顶向上隆起值减小,周边位移减小,仰拱隆起加剧;深埋侧右洞拱顶下沉减小,周边位移增加,仰拱隆起稍有增加;反压护拱厚度增加能显著缓解隧道浅埋侧左洞和中夹岩柱的偏压程度,而对缓解深埋侧右洞的偏压不明显。根据围岩塑性区体积随反压护拱厚度的变化情况,建议在地表注浆加固后,Ⅴ级围岩宜施作5m厚的反压护拱。
In order to study the influence of back-arch arching construction on the stability of shallowly-biased shallow-clearance tunnels, the construction process of back-pressure arched arches of the algae tunnel was introduced. Based on the background of this project, FLAC3D finite difference software Different thickness of the back arch tunnel under the excavation process. By analyzing the displacement, stress and plastic zone changes of the surrounding rock, the influence law of the thickness of the back-arched support arches on the stability of shallowly-biased tunnels with shallow buried depth is obtained. The results show that with the increase of the thickness of the back arched support, the uplift value of the shallow dome-shaped left dome decreases, the displacement of the periphery decreases, and the uplift of the uplift aggravates. The settlement of the dome on the deep right side decreases and the displacement of the periphery While the uplift of inverted arch increased a little. The increase of back arching arching thickness can significantly reduce the bias of left and middle rock columns in the shallow buried side of the tunnel, while the bias of deep right side cave is not obvious. According to the change of the plastic zone volume of the surrounding rock with the back-up arching thickness, it is suggested that the Ⅴ surrounding rock should be applied with 5m thick back-arch arches after the surface grouting reinforcement.