Study on Control Measures of Surrounding Rock Deformation of Tunnel in Fly Ash Stratum
Based on the Yanpingba multi-arch tunnel project,when the tunnel passes through the complex accumulation area of fly ash,due to the poor stability of the surrounding rock in the tunnel section during excavation,when the support is not timely or the bearing capacity of the support structure is insufficient,it is easy to cause large-scale deformation and instability of the surrounding rock.In this paper,through the combination of data research and numerical simulation,the reasonable reinforcement scheme for fly ash accumulation stratum is studied.FLAC 3D software is used to verify the advanced support and pre-reinforcement measures,and the evaluation is carried out according to the field application effect.The results show that:(1)after stratum reinforcement,the vertical displacement of tunnel vault decreases sharply,and the maximum displacement of main tunnel vault changes around 20mm,indicating that the self-stability of surrounding rock is improved;(2)the final settlement of the ground surface under different working conditions is only about 1.3 mm,and the influence range of the ground surface during tunnel excavation is significantly reduced after stratum reinforcement;(3)after the reinforcement of the stratum,the displacement of the vault is less than 4cm,and the reinforcement effect is remarkable.
layer of pulverized coal ashstratum reinforcementadvanced supportdeformation of surrounding rock
万方数据
维普
