Stability analysis and deformation control method of swelling soft rock roadway adjacent to chambers

• Published in: Geomechanics and geophysics for geo-energy and geo-resources. 2023-12, Vol.9 (1), Article 91
• Main Authors: Zhang, Wei, Zhao, Tong-bin, Zhang, Xu-tao
• Format: Article
• Language: English
• Subjects: Anchor bolts; Cementation; Chambers; Clay minerals; Coal mines; Control methods; Deformation; Deformation analysis; Dredging; Energy; Engineering; Environmental Science and Engineering; Excavation; Failure mechanisms; Foundations; Geoengineering; Geological surveys; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Hydraulics; Roads; Rock; Rocks; Sheds; Sprayed concrete; Stability analysis; Steel; Stress concentration; Swelling; Working conditions
• ISSN: 2363-8419; 2363-8427
• DOI: 10.1007/s40948-023-00635-y

The surrounding rock of swelling soft rock roadway has high clay mineral content, strong expansibility after encountering water, low strength and poor cementation. The roadway is prone to large deformation under the influence of complex geostress. Combined with the support change of the development roadway of 2# coal in Hongqingliang mine, through geological survey, field observation and indoor test, the failure mechanism of the traditional support method of “anchor bolt + anchor cable + anchor mesh + shotcrete” was revealed by the adjustment of the surrounding rock stress after the excavation and support of the adjacent chambers. The research results show that the surrounding rock stress will cross the adjacent chambers and form a concentrated area near the weakly cemented roadway, and the maximum stress increase ratio of surrounding rock within the stress concentration range will reach 50%. The farther the chambers are from the weakly cemented roadway, the smaller the range of the surrounding rock stress concentration area. When the distance exceeds about 12 times the average height of the chambers, the surrounding rock stress concentration tends to disappear. Based on the fully enclosed combined support method of the "U-shaped steel sheds closure roof and sides + filling flexible material behind the sheds + laying reinforcement mesh and concrete in floor + strengthening key parts", the construction process flow applicable to the working condition of swelling soft rock roadway is formulated. Article Highlights Control method of swelling soft rock roadway adjacent to chambers. U-shaped steel sheds closure roof and sides + filling flexible material behind the sheds. The vertical stress is mainly transmitted to the vertical direction.