王东英, 尹小涛, 汤华, 邓琴. 2018: 隧道锚承载机制及承载力探究. 工程地质学报, 26(s1): 214-218. DOI: 10.13544/j.cnki.jeg.2018129
    引用本文: 王东英, 尹小涛, 汤华, 邓琴. 2018: 隧道锚承载机制及承载力探究. 工程地质学报, 26(s1): 214-218. DOI: 10.13544/j.cnki.jeg.2018129
    WANG Dongying, YIN Xiaotao, TANG Hua, DENG Qin. 2018: THE BEARING MECHANICS AND CAPACITY OF TUNNEL-TYPE ANCHORAGE. JOURNAL OF ENGINEERING GEOLOGY, 26(s1): 214-218. DOI: 10.13544/j.cnki.jeg.2018129
    Citation: WANG Dongying, YIN Xiaotao, TANG Hua, DENG Qin. 2018: THE BEARING MECHANICS AND CAPACITY OF TUNNEL-TYPE ANCHORAGE. JOURNAL OF ENGINEERING GEOLOGY, 26(s1): 214-218. DOI: 10.13544/j.cnki.jeg.2018129

    隧道锚承载机制及承载力探究

    THE BEARING MECHANICS AND CAPACITY OF TUNNEL-TYPE ANCHORAGE

    • 摘要: 隧道锚的承载性能是隧道锚设计和工程应用需要解决的基本科学问题。隧道锚是底部大、上部小、呈倒塞体形的锚体结构,这一几何特征使得荷载作用下锚-岩界面产生附加应力。为探究不同加载阶段隧道锚承载部位和承载力的差异,通过分析各阶段附加应力变化情况建立不同加载阶段隧道锚承载力的表达式,并通过某大桥隧道锚现场缩尺模型试验对所推导公式进行实例验证。发现:隧道锚的承载阶段包括初始阶段、弹性阶段和塑性阶段3部分,隧道锚的初始承载力取决于锚碇体自重,峰值承载力则与隧道锚的破坏形态、附加应力大小直接相关。某大桥隧道锚沿锚-岩界面破坏,其初始承载力为1540 MN,是设计荷载的7倍;峰值承载力为3080 MN,是设计荷载的14倍。现场缩尺试验揭露的隧道锚临界承载力和极限承载力分别为设计荷载的9倍和13倍。以上结果表明:(1)不同加载阶段,隧道锚-岩体联合承载力的部位、岩体参与抗拔的范围、夹持锚碇体的程度均不相同;(2)隧道锚承载力的阶段性由锚-岩界面附加应力的变化引起;(3)建立的承载力估值公式与现场试验吻合性较好,可用于指导隧道锚设计。

       

      Abstract: The study on the bearing behavior of tunnel-type anchorage is the one of the basic scientific questions in the design and application of this type anchorage. Tunnel-type anchorages look like inverted-shape structures with bigger bottom and smaller top. This geometrical characteristic may be the main reason that the additional stress could initiate on the interface of anchor and rock under the main cable load. In order to study the difference of bearing capacity of tunnel-type anchorage in different load stage, the formulas of bearing capacities of anchorage are built with the analysis of the change law of additional stress. And these formulas are verified by the results of field model test. We find that:the load stages of tunnel-type anchorage can be classified as original stage, elastic stage and plastic stage. And the value of initial bearing capacity of tunnel-type anchorage relies on the gravity of the anchor while the ultimate capacity depending on the failure modes and additional stress. Besides, the failure surface of the object anchorage happens on the interface of the anchor and rock. And the initial bearing capacity of the support project is 1540MN,seven times higher than design load. The ultimate bearing capacity reaches to 3080MN,fourteen times higher than design load. While the results obtained from the field model test are 9 and 13 times higher than design load respectively. The results tell us that the bearing position, the range of rock taking part in the different stage and the degree of rock holding the anchor are different in different load stage. Moreover, the stage characteristics of tunnel-type anchorage capacity are closely relevant to the additional stress. And the geological characteristic of tunnel-type anchorage improves the bearing capacity tremendously. Last but not least, the estimation formulas for the bearing capacity is agree with the results of model test and can be applied to guide the design of tunnel-type anchorage.

       

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