论文部分内容阅读
为了研究LDP位移释放率、扩挖量、护盾锥度、护盾长度和侧压力系数等因素对双护盾TBM与围岩相互作用的影响,采用FLAC3D建立了三维TBM模型,在考虑护盾与围岩不均匀间隙的条件下研究了TBM作用下上述因素对围岩变形、接触挤压力大小及分布和护盾所受摩阻力的影响。同时定义了LDP曲线的位移释放率,得出应力释放率超过特定值时对LDP曲线释放率和TBM护盾阻力的影响显著,而且针对特定工程地质条件应做其敏感度的预分析;不均匀间隙自下而上逐渐闭合导致围岩与护盾逐渐发生接触,前后盾尾受力最为显著;前后护盾摩阻力及总摩阻力均与扩挖量呈线性递增关系,适当增加扩挖量可以有效减小护盾阻力;护盾摩擦力与护盾长度呈线性递增关系;当增加护盾锥度时,刀盘及前盾摩阻力缓慢增加,后盾摩擦力减小较为明显,护盾总摩擦力也减小;侧压力系数超过1.2时对刀盘、前盾及后盾上的摩擦阻力影响显著。以上研究成果对于进一步认识和研究TBM与围岩相互作用及后续预测卡机有着重要参考意义。
In order to study the influence of LDP displacement release rate, excavation volume, shield taper, shield length and lateral pressure coefficient on the interaction between double-shield TBM and surrounding rock, a 3D TBM model was established by using FLAC3D. The influence of TBM on the surrounding rock deformation, the contact extrusion pressure and the distribution and the frictional resistance of the shield were studied under the condition of uneven surrounding rock. At the same time, the displacement release rate of LDP curve is defined. It is concluded that the release rate of LDP exceeds the specified value, and the release rate of LDP curve and the shield resistance of TBM are significantly affected. Moreover, the pre-analysis of sensitivity should be made for specific engineering geological conditions. The gap closes gradually from bottom to top, which leads to the gradual contact between the surrounding rock and the shield. The shield force at the front and the back of the shield is the most significant. The frictional resistance and total friction of the shield increase linearly with the digging volume. Which can effectively reduce the shield resistance; shield friction and shield length linearly increasing relationship; when increasing the shield taper, the friction resistance of the cutterhead and front shield slowly increases, the shield friction decreases more obviously, the total shield friction Decrease; Side pressure coefficient of more than 1.2 on the cutter, the front shield and the friction on the impact of significant. The above research results have important reference significance for further understanding and researching TBM interaction with surrounding rock and subsequent card forecasting machine.