基于现场数据的TBM超小转弯工况下掘进参数研究

Study on TBM Tunnelling Parameters Under Ultra-small-radius Turning Conditions Based on Field Data

为研究TBM掘进参数在超小转弯工况下的变化规律,基于TBM法开挖浙江缙云抽水蓄能电站排水廊道工程,对TBM转弯流程进行分析,得到护盾调整量是影响TBM最小转弯半径的主要因素;对滚刀破岩进行受力分析,得到滚刀受力与各参数间相互作用的机理。根据现场实际掘进数据,分析在不同岩石单轴抗压强度、岩体完整性系数和节理走向与隧洞掘进方向夹角的条件下,TBM刀盘贯入度、刀盘推力和刀盘扭矩间的关系。研究结果表明,TBM在超小转弯半径掘进工况下,贯入度随刀盘推力增大呈对数函数增长,刀盘扭矩随贯入度增大呈指数函数增长,增长率与岩石参数密切相关。进一步建立掘进参数与岩石参数间的预测模型,并进行多组实际工程预测,预测结果的平均相对误差小于10%,表明预测模型的预测精度较高。

In order to study the variation law of TBM tunnelling parameters under ultra-small-radius turning conditions,the TBM-driven drainage gallery project of Jinyun Pumped Storage Power Station in Zhejiang Province is taken as an example for analysis.The TBM turning process is analyzed to find out that the adjustment amount of the shield is the main factor affecting the minimum turning radius of TBM.The forces on the disc cutters during rock breaking are analyzed to obtain the mechanism of interaction between the forces and various parameters.On the basis of on-site actual tunnelling data,the relationship among the penetration,thrust and torque of the TBM cutterhead under different rock uniaxial compressive strengths,rock mass integrity coefficients,and included angles between joint strike and tunnelling direction are analyzed.The analysis results show that under ultra-small-radius tunnelling conditions,the penetration increases logarithmically with the increase of thrust,and the torque increases exponentially with the increase of penetration,the increase rates being closely related to rock parameters.In addition,a prediction model for tunnelling parameters and rock parameters is established to carry out multiple groups of actual predictions for projects.The prediction results have an average relative error of less than 10%,indicating a high prediction accuracy of the prediction model.