浅埋偏压小净距隧道围岩压力分布与围岩控制

Distribution and Control of Surrounding Rock Pressure of Shallow Buried Tunnel under the Condition of Terrain Bias

根据浅埋偏压小净距隧道受力特点,研究推导了考虑施工工序及地形坡度的浅埋偏压小净距隧道围岩压力计算公式。分析了考虑不同地形坡度及同一坡度不同埋深2种工况下地形坡度及埋深对围岩破裂范围、水平侧应力、拱顶压力的影响规律,并指出了浅埋偏压小净距隧道围岩压力在考虑地形坡度下与水平地表下分布规律的差异,建立了3DEC数值模型以对上述理论规律进行验证,结果表明,数值分析规律与理论推导计算规律相吻合。将理论计算公式应用于马嘴隧道出口浅埋段隧道稳定性计算,由计算所得围岩稳定性系数及现场隧道变形监测结果提出隧道围岩及地表稳定性处理措施。

According to the stress characteristics of the small space tunnel under the bias voltage,the calculation method of the surrounding rock pressure considering the construction process and the terrain slope of shallow-buried bias tunnel were studied. The influence of the surrounding rock failure range,the horizontal and roof stress by the terrain slope and buried depth were analyzed under two conditions of different topographic gradients and different depth of the same slope,then the differences of surrounding rock pressure distribution between the small spacing tunnel that consider the topographic slope angle and the small spacing tunnel with horizontal surface is pointed out.The 3 DEC numerical model is established to verify the above theoretical rules,the results show that the numerical analysis is in agreement with the theoretical analysis. Then,the theoretical calculation formula is applied to the stability calculation of Mazui tunnel. The stability of tunnel surrounding rock and surface treatment measures proposed by the calculated coefficient of surrounding rock stability and deformation monitoring results of field tunnel.