隧道锚尺寸对其承载特性的影响及破坏机理

发布时间：2018-02-03 16:39

本文关键词： 隧道锚软岩结构尺寸承载特性破坏模式数值模拟　出处：《地下空间与工程学报》2017年05期 　论文类型：期刊论文

【摘要】：锚碇作为跨江悬索大桥的重要组成部分,其变形位移和受力状态直接影响到悬索桥的安全和长期使用的可靠性,而锚碇体的埋深、大小和长度等因素都会对隧道锚的承载性能产生影响。本文以某长江大桥北岸拟建于泥岩上的隧道式锚碇为背景,在保证挖方量一定情况下,通过控制锚碇埋深、截面尺寸、扩展角及锚塞体长度4个参数,采用FLAC-3D有限差分研究了隧道锚各结构尺寸参数对其承载性能的多因素综合影响。结果表明,在承载力较低的软岩上修建浅埋隧道锚,锚碇体最大变形位移主要与后锚面的尺寸有关,后锚面尺寸越大,隧道锚承载特性越好。同时获得了优于原设计的锚碇结构各尺寸参数。对已建成的实桥锚固系统的破坏全过程进行了模拟分析,结果表明,其破坏模式为锚碇围岩受侧向挤压后产生破裂而导致的锚碇体被整体拔出,以供工程参考。
[Abstract]:Anchorage is an important part of suspension bridge across the river. Its deformation displacement and stress state directly affect the safety and reliability of the suspension bridge and the buried depth of the Anchorage. Such factors as size and length will affect the bearing capacity of tunnel anchors. This paper takes the tunnel Anchorage proposed to be built on mudstone on the north bank of a Yangtze River Bridge as the background, under the condition of ensuring a certain amount of excavations. By controlling the depth of the Anchorage, the size of the section, the expansion angle and the length of the anchor plug, four parameters are obtained. FLAC-3D finite difference method is used to study the influence of various structural dimensions of tunnel anchors on their bearing capacity. The results show that shallow tunnel anchors are built on soft rock with low bearing capacity. The maximum deformation displacement of the Anchorage is mainly related to the size of the rear Anchorage surface, and the larger the size of the rear Anchorage surface is. The better the bearing characteristics of tunnel anchors, and the better than the original design of the Anchorage structure size parameters. The failure process of the completed real bridge Anchorage system is simulated and analyzed, the results show that. The failure mode of the Anchorage is that the Anchorage rock mass is pulled out by the whole, which is caused by the rupture of the surrounding rock under lateral compression, for engineering reference.
【作者单位】：山地城镇建设与新技术教育部重点实验室(重庆大学);重庆大学土木工程学院;
【基金】：国家自然科学基金(41772319,41772306) 重庆市研究生科研创新项目(CYS16005)
【分类号】：U448.25
【正文快照】： 工程学院,重庆400045)0引言锚碇作为悬索桥最主要的承力构件,按构造形式分为重力式锚碇和隧道式锚碇[1]。重力式锚碇主要依靠锚碇混凝土的自重承受主缆拉力,其锚碇工程数量较大,成本较高,适用于桥头两岸为松散土或水域。倒塞形结构形式的隧道式锚碇[2,3],通过锚碇体与围岩的相

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