Calculation and model test verification of outburst prevention rock plate of tunnels in water-rich fault fracture zones
There are issues with the present tunnel outburst preventive rock plate thickness calculation method and the water-rich fault fracture zone mechanical model,such as incomplete factors and significant calculation error.Based on Janssen's theory,parameters such as the horizontal angle between the tunnel axis and the fault fracture zone surface,the fault dip angle and the groundwater depth are introduced.The correction calculation formula for the outburst prevention rock plate thickness of the tunnel crossing the water-rich fault fracture zone is derived and verified by model test.On this basis,the influences of fracture zone distribution,fault fracture zone dip angle,water pressure and other factors on the rock plate thickness of tunnel are revealed.The results show that the calculation formula of the outburst prevention rock plate thickness has good applicability under the two conditions including fault fracture zone is inward/outward compared with rock plate for outburst prevention.Meanwhile,the thickness of tunnel outburst prevention rock plate increases with the increase of fault fracture zone distribution,water pressure,tunnel section and buried depth,and decreases with the increase of fault fracture zone inclination,the strength of ordinary surrounding rock and the intersection Angle between tunnel axis and fault fracture zone.The research results can provide theoretical reference for the anti-outburst safety calculation of similar tunnel engineering.
tunneling engineeringwater-rich fault fracture zoneJanssen's theorythickness of outburst prevention rock plateinfluencing factors
NETL
NSTL
万方数据
