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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。
Anchorage as an important part of the cross-river suspension bridge, the deformation displacement and stress directly affect the safety of the suspension bridge and long-term use of reliability, and anchorage body depth, size and length of the tunnel anchor The bearing capacity has an impact. In this paper, based on the tunnel anchorage built on the mudstone in the north bank of a Yangtze River Bridge, under the condition of certain amount of excavation, the four parameters of depth, section size, expansion angle and anchor plug length are controlled by FLAC -3D finite difference method to study the multi-factor comprehensive effect of the size parameters of the tunnel anchor on its bearing capacity. The results show that the maximum deformation and displacement of anchored anchors are mainly related to the size of the rear anchorage when the shallow tunnel anchor is constructed on soft rock with low bearing capacity. The larger the size of the rear anchorage, the better the bearing capacity of the tunnel. At the same time, the size of the anchoring structure is better than that of the original design. The whole process of the failure of the existing real bridge anchoring system is simulated and the results show that the failure mode is that the anchoring body is pulled out as a whole due to the rupture of the surrounding rock of the anchorage due to lateral extrusion, reference.