Study on pressure arch effect of xigeda strata tunnel based on experiment and discrete element simulation

• Published in: Bulletin of engineering geology and the environment 2022-05, Vol.81 (5), Article 199
• Main Authors: Zhou, Ping, Jiang, Yifan, Zhou, Feicong, Li, Jinyi, Lin, Ming, Lin, Jiayong, Wang, Zhijie
• Format: Article
• Language: English
• Subjects: Earth and Environmental Science; Earth Sciences; Foundations; Geoecology/Natural Processes; Geoengineering; Geotechnical Engineering & Applied Earth Sciences; Hydraulics; Nature Conservation; Original Paper
• ISSN: 1435-9529; 1435-9537
• DOI: 10.1007/s10064-022-02700-4

Xigeda strata which is widely distributed in southwestern China are composed of semi-diagenetic rock that will soften by water. The existing load calculation methods are not suitable for semi-diagenetic strata. In this paper, the pressure arch of the Xigeda stratum tunnel is studied to determine the surrounding rock load, and the pressure arch form and dynamic development process of the pressure arch of the tunnel in Xigeda strata are explored through model tests and PFC simulation. The study found that: moisture content is an important factor affecting the distribution of pressure arches in the Xigeda strata tunnel, and the size and thickness increase with the increase of moisture content; the formation of pressure arches has significant time and space effects. The construction of tunnels in high moisture content stratum requires timely support to protect tunnel safety; the load calculation method proposed by the pressure arch study takes into account the special properties of the Xigeda strata. The calculated surrounding rock pressure is closer to the measured value and can be used to calculate the surrounding rock load.