城市软弱围岩隧道塌方特征及演化规律试验研究

发布时间：2018-01-09 12:34

本文关键词：城市软弱围岩隧道塌方特征及演化规律试验研究　出处：《岩石力学与工程学报》2014年12期 　论文类型：期刊论文

【摘要】：塌方是城市软弱围岩隧道施工过程中的主要安全风险之一,而明确塌方特征及其演化规律是防控隧道塌方的前提和基础。通过模型试验,针对均质软弱围岩深埋隧道和浅埋隧道2种情况分别研究其塌方特征和演化规律。结果表明,2种埋深条件下均表现出围岩破坏的渐进性和隧道塌方的突发性等典型特征,但也各有特点:(1)深埋隧道围岩破坏不会波及地表,塌方一般发生多次且每次均会形成短时稳定的塌落拱,并最终形成一个稳定的塌落拱,且所有塌落拱形状均表现出典型的二次抛物线特征;(2)浅埋隧道围岩破坏会波及地表并最终造成地表塌陷,围岩破坏过程中也会形成短时稳定的塌落拱,其形状也可以用二次抛物线进行拟合;(3)深埋隧道围岩破裂面自洞室两侧边墙处开始并逐渐向上方发展,而浅埋隧道的地表则先于洞周围岩发生破裂,因此,深埋隧道塌方防控的重点应放在洞内,而浅埋隧道塌方防控的重点则应洞内和地表并举。
[Abstract]:Collapse is one of the main safety risks in the construction process of city soft surrounding rock tunnel, and it is the premise and foundation of preventing and controlling tunnel collapse to make clear the characteristics of collapse and its evolution law. The collapse characteristics and evolution law of deep buried tunnel and shallow buried tunnel in homogeneous soft surrounding rock are studied respectively. Under the two kinds of buried depth conditions, both show the typical characteristics such as gradual failure of surrounding rock and sudden collapse of tunnel collapse, but also have their own characteristics: 1) the destruction of surrounding rock in deep buried tunnel will not affect the surface of the earth. Collapse usually occurs many times and each time will form a stable collapse arch, and finally form a stable collapse arch, and all the collapse arch shape shows a typical quadratic parabola characteristics; (2) the failure of shallow tunnel surrounding rock will spread to the surface of the earth and eventually cause the surface collapse, and a stable collapse arch will be formed in the process of surrounding rock failure, and its shape can also be fitted with a quadratic parabola; (3) the wall rock fracture surface of the deep buried tunnel begins from the side wall on both sides of the tunnel and gradually develops upward, while the surface of the shallow buried tunnel is ruptured before the surrounding rock of the tunnel, so. The prevention and control of deep buried tunnel collapse should be focused on the hole, while that of shallow tunnel collapse prevention and control should be carried out simultaneously in the hole and the surface.
【作者单位】：北京交通大学城市地下工程教育部重点实验室;
【基金】：国家重点基础研究发展计划(973)项目(2010CB732100) 国家自然科学基金面上项目(51378002) 北京市自然科学基金面上项目(8122034)
【分类号】：U451.2
【正文快照】： 1引言隧道施工过程中,塌方是常见的围岩失稳破坏模式之一。由于其具有复杂的非线性和突发性等特征,难以预测,已成为隧道施工中一个极为突出的安全隐患,一旦发生塌方事故,将会造成施工困难、机械损毁、工期延误以至人员伤亡等巨大损失[1-3],此类隧道工程事故案例屡见不鲜。在城

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