Aug 2026· Geotechnical Testing Journal· 0 citations· 25 references
Abstract
Rock bolts are widely used as initial tunnel support, yet the collaborative load-bearing mechanism between bolts and surrounding rock remains unclear. This study investigates this behavior through geomechanical physical model experiments based on a tunnel project in southwest China. Key parameters, including stress and displacement evolution, damage zone distribution, and bolt axial force, were examined at various excavation stages. Results show that: (1) the surrounding rock bears over 98 % of the total load, while bolts carry only a minor portion; (2) bolting significantly enhances rock mass performance, increasing ultrasonic wave velocity by 2.2 %–15.4 % and reducing damaged zone thickness by 3.7 %–28.5 %; (3) stress release is more pronounced at the crown and invert, leading to larger deformations and higher bolt axial forces, whereas the shoulder and sidewall experience lower forces. These findings offer practical guidance for tunnel construction and support optimization.
This study reviews the development of research on systematic-rock-bolt effectiveness in soil tunnels and clarifies the mechanism of rock-bolt inefficiency. Field statistics show that rock-bolt axial forces in soil tunnels are generally low or even compressive, especially at the arch crown, indicating limited contributi...
Jin-Chun Xia, Fu-Qiang Liu, Hao-Nan Sun et al.· Transportation Research Reco...· 0 citations
Large deformation is one of the most critical hazards in tunnels excavated under complex geological conditions. It often causes significant economic losses and threatens construction safety. For layered soft rock tunnels subjected to high in situ stress, the deformation and failure mechanisms are largely governed by th...
Rui-Qi Guo, Jun-Qi Lai, Tian-Zhu Ye et al.· Applied Sciences· 0 citations
Large deformation of surrounding rock is a critical challenge during TBM tunnelling in deeply buried high
in situ
stress soft rock, where delayed deformation and insufficient support stiffness may lead to support failure and machine jamming. However, the quantitative influence of rock bolt support parameters on def...
Zhen-Xing Yang, Kai Zhang, Yu-Lu Li et al.· Frontiers in Earth Science· 0 citations
Fully grouted rock bolts are widely used for ground control in underground excavations and slopes. Their behaviour under axial and shear loading is governed by bond-slip at the interfaces, confinement, embedment length, annulus thickness and bolt profile, which together control peak capacity and post-peak load transfer...
Shima Entezam, A. Mirzaghorbanali, B. J. Shokri et al.· Australian Geomechanics Jour...· 0 citations
Rock bolts and steel arches are common methods of support used in tunnel engineering. To compare the support efficiency of rock bolts and steel arches, numerical simulations were conducted using discrete element software to analyze the mechanical response characteristics and tunnel stability of support systems. Firstly...
Wei-Teng Li, Guang-Hui Yang, Bing-Jun Sun et al.· Transportation Research Reco...· 0 citations
