C 形管锚固体结构面抗剪性能的试验研究。

Experimental study on the shear performance of an anchor cable with a C-shaped tube anchored flat structural plane.

机构信息

School of Mechanics and Civil Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China.

出版信息

Sci Rep. 2023 Jan 16;13(1):797. doi: 10.1038/s41598-023-28105-1.

DOI:10.1038/s41598-023-28105-1

PMID:36646796

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC9842618/

Abstract

To analyse the influence of normal stress (σ) and steel tube strength on an anchor cable with a C-shaped tube (ACC), we selected Q235 steel tubes and Q345 steel tubes as representative ACCs and carried out double shear tests of ACC-reinforced jointed rock masses. Based on the test results, the influence of the steel tube strength on the ACC axial force and shear force under different normal stresses, the characteristics of the shear force-shear displacement curve of the anchored flat structural plane (FSP) in the rock mass, and the ACC failure mode and contribution to the anchored concrete surface shear strength were studied. The test results show that under 2 ~ 10 MPa of σ, the failure angle varies between 28° and 40° due to the bending of the ACC near the structural plane and increases with increasing σ. Compared with Q235-ACC, Q345-ACC contributes more to the shear strength of the structural plane and can better exert its axial force when resisting the lateral shearing action of the structural plane. Additionally, we proved that σ is a main factor affecting the shear stiffness of the structural plane and that the Q345 C-shaped tube effectively improves the shear stiffness of an ACC-reinforced jointed rock mass and can more fully mobilize the anchor cable during shearing ductility in the tangential direction compared to the performance of the Q235 C-shaped tube. The research results can provide a reference for the further application of ACCs to roadways.

摘要

为分析法向应力(σ)和钢管强度对 C 形管锚索(ACC)的影响，选取 Q235 钢管和 Q345 钢管作为典型的 ACC，进行了 ACC 加固节理岩体的双剪试验。基于试验结果，研究了钢管强度对不同法向应力下 ACC 轴力和剪力的影响、锚固平面结构面(FSP)剪切位移曲线的特点、ACC 的破坏模式及其对锚固混凝土表面剪切强度的贡献。试验结果表明，在 2~~10 MPa 的 σ 下，由于结构面附近的 ACC 弯曲，破坏角在 28°~~40°之间变化，且随着 σ 的增大而增大。与 Q235-ACC 相比，Q345-ACC 对结构面剪切强度的贡献更大，在抵抗结构面的横向剪切作用时，能更好地发挥其轴力。此外，还证明了 σ 是影响结构面剪切刚度的主要因素，Q345 C 形管有效地提高了 ACC 加固节理岩体的剪切刚度，与 Q235 C 形管相比，在切向延性剪切过程中能更充分地调动锚索。研究结果可为 ACC 在巷道中的进一步应用提供参考。