Abstract:Research purposes:The deformation characteristics and bearing mechanism of the interaction between anchor plug body and surrounding rock of shallow layered soft rock tunnel-type anchorage are complex, and it is difficult to analyze and study with specifications or engineering analogies. In order to study the deformation law, failure characteristics and bearing characteristics of tunnel-type anchorages, the deformation characteristics and bearing capacity safety factor of tunnel-type anchorages are determined through on-site 1 ∶10 scale model tests, and the effects of soft rock, shallow burial, bedding plane and other factors on tunnel-type anchorages are explored. Finally, the safety and stability of tunnel-type anchorages are evaluated. Research conclusions:(1) The deformation of the tunnel-type anchorage occurs from the back anchorage surface and attenuates to surrounding rock under all levels of loads. And the deformation of the anchorage plug and the surrounding rock on the left and right sides presents a symmetrical double hump shape. (2) Under the design load, the deformation of the anchorage plug is the largest, and the maximum deformation is 0.054 mm, and the predicted maximum deformation of the prototype tunnel-type anchorage is about 0.5 mm. (3) The ultimate bearing capacity of the tunnel-type anchorage reaches 18 times of the design load. Under the ultimate load, the anchorage plug carries the shallow buried rock mass directly above to have the inclined upward arch failure. The fracture surface comes from the bedding plane original crack to expand and the failure range exceeds 4 times the tunnel diameter. (4) All these show that the deformation limit and the safety factor of surrounding rock meet the requirements of the specification and tunnel-type anchorage is safe and stable. (5) The research results can provide a reliable basis for the safety evaluation of the tunnel-type anchorage system of Youxi Yangtze River Bridge, and also provide technical reference for related projects.
乔雷涛, 康炜, 文强. 深路堑内浅埋层状软岩隧道锚特性试验研究[J]. 铁道工程学报, 2022, 39(10): 47-52.
QIAO Leitao, KANG Wei, WEN Qiang. Experimental Research on the Characteristics of Shallow Layered Soft Rock Tunnel-type Anchorage in Deep Cutting. Journal of Railway Engineering Society, 2022, 39(10): 47-52.
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