Study on the Splitting Mechanical Properties of Asymmetric Large Deformation Surrounding Rock Mass in Deep Underground Engineering

10.6919/ICJE.202205_8(5).0059

Shuguo Zhang；Ling Dai；Xiaohu Yuan；Yongbiao Lai

Deep Underground Engineering ； Large Deformation ； Brazil Splitting ； Weathering ； Failure Mode

International Core Journal of Engineering

8卷5期（2022 / 05 / 01）

465 - 470

英文

The mechanical properties of carbonaceous slate will weaken under the interaction of water-rock and natural weathering after tunnel construction, which will lead to the instability failure of deep underground engineering such as tunnel and slope. Therefore, the carbonaceous slate in the Muzhailing tunnel of Gansu Province was taken as the research object, and the Brazilian splitting test was carried out on the natural weathered samples (after processing, the samples were placed under normal temperature ventilation for 90 days) to analyze the effect of different bedding angles on the force-displacement characteristics and failure modes of the carbonaceous slate. The results show that the force-displacement curves of carbonaceous slate under different bedding angles have an approximate variation trend, and the vertical displacement and peak load increase gradually with the increase of inclination angle. The experimental data shows great discretization due to the influence of micro-cracks, water-rock interaction and natural weathering. In terms of the failure mode of carbonaceous slate, tensile fracture or tensile shear failure occurs along the bedding plane when the bedding angle is close to 0°. When the bedding angle is close to 90°, tensile fracture, shear fracture or compression fracture occur. The failure state also presents asymmetrical distribution and some differences due to the comprehensive effects of mineral matrix, bedding, defects, water-rock and weathering.

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