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Research on Anchorage Mechanism of Yielding Support in the Deep-buried Tunnel
(1 College of Architectural Engineering, Dalian University, Dalian 116622; 2 Key Laboratory of Disaster Prediction and Control of Complex Structure System, Dalian University, Dalian 116622)
Abstract To investigate the effect of yielding support structure on zonal fracturing of surrounding rock and its an? chorage mechanism in the deep-buried tunnel in stratified stratum, a three-dimensional similar material physical model test of the deep-buried tunnel under high geo-stress was carried out. A contrast study on the four kinds of support structures (rigid lining, rigid lining + yielding anchor bolt, flexible lining and flexible lining + yielding anchor bolt) was taken by laying and tamping the similar materials with proportions of 3∶3 and 4∶3 respectively. The stress test results show that peak stress and trough stress both occur at tunnel crown, spandrel and sidewall in conditions of rigid lining and flexible lining, and it has a tendency of zonal fracturing for the surrounding rock, while the tendency of wave-shape stress variation is declining in condition of rigid lining + yielding anchor bolt, which shows the support structure restrains the tendency of zonal fracturing of rock mass. The strain monitoring results of yielding anchor bolt show that tensile strain and compression strain occur alternatively for the yielding anchor bolt at tunnel crown in conditions of rigid lining and flexible lining, while only tensile strain occurs for the yielding anchor bolt at spandrel and sidewall in condition of flexible lining. The combination support of rigid lining + yielding anchor bolt is significant for restraining zonal fracturing of surrounding rock of the deep-buried tunnel.
Abstract：
To investigate the effect of yielding support structure on zonal fracturing of surrounding rock and its an? chorage mechanism in the deep-buried tunnel in stratified stratum, a three-dimensional similar material physical model test of the deep-buried tunnel under high geo-stress was carried out. A contrast study on the four kinds of support structures (rigid lining, rigid lining + yielding anchor bolt, flexible lining and flexible lining + yielding anchor bolt) was taken by laying and tamping the similar materials with proportions of 3∶3 and 4∶3 respectively. The stress test results show that peak stress and trough stress both occur at tunnel crown, spandrel and sidewall in conditions of rigid lining and flexible lining, and it has a tendency of zonal fracturing for the surrounding rock, while the tendency of wave-shape stress variation is declining in condition of rigid lining + yielding anchor bolt, which shows the support structure restrains the tendency of zonal fracturing of rock mass. The strain monitoring results of yielding anchor bolt show that tensile strain and compression strain occur alternatively for the yielding anchor bolt at tunnel crown in conditions of rigid lining and flexible lining, while only tensile strain occurs for the yielding anchor bolt at spandrel and sidewall in condition of flexible lining. The combination support of rigid lining + yielding anchor bolt is significant for restraining zonal fracturing of surrounding rock of the deep-buried tunnel.
CHEN Zhuoli1,
2 ZHU Xunguo1,
2 ZHAO Deshen1 etc
.Research on Anchorage Mechanism of Yielding Support in the Deep-buried Tunnel[J] MODERN TUNNELLING TECHNOLOGY, 2019,V56(4): 16-22
2019, Vol. 56 