基于电磁辐射的隧道变形多参数模型及其应用

Construction and Application of Multi-parameter Model for Tunnel Deformation Based on Electromagnetic Radiation

为了定量分析电磁辐射参数与围岩变形破裂的关系,提高变形预测的准确性,基于丽香铁路中义隧道的219组现场实测数据,采用相关分析方法对电磁辐射参数与隧道变形量、变形速率的相关性进行研究;选用电磁辐射强度、脉冲、能量指标中与隧道变形量、变形速率最相关的参数,基于偏最小二乘法(PLSR)建立了隧道变形量和变形速率的多参数模型;通过实测数据检验了模型的有效性,并利用该模型对开挖后隧道断面的变形演化规律进行了预测。结果表明:1)电磁辐射强度极大峰值事件数占比、脉冲数、超过平均能量的峰值事件数及三者的波动速率占比分别是电磁辐射强度、脉冲、能量指标中与隧道变形量、变形速率最相关的参数;2)采用偏最小二乘法建立了隧道变形量和变形速率的三参数PLSR模型,两者计算值与实测值的相关系数分别为0.838和0.927,验证了该模型的有效性;3)现场预测结果显示,三参数PLSR模型的预测值比一元回归模型更接近实测值,且预测可靠性更稳定。实际工程中,应综合电磁辐射强度、脉冲和能量3类指标,建立隧道变形的多参数预测模型,以便更准确地反映隧道的实际变形规律,提高电磁辐射技术在工程实际中的现场应用水平。

In order to quantitatively analyze the relationship between electromagnetic radiation(EMR)parameters and the deformation and fail-ure of tunnel surrounding rock,and improve the prediction accuracy of tunnel deformation,the correlation between EMR parameters and tunnel deformation(including deformation amount and deformation rate)were analyzed by correlation analysis method based on 219 sets of field test data of Zhongyi Tunnel on Lixiang Railway.The most relevant parameters among the intensity,pulse and energy indexes were used to develop the new multi-parameter models for tunnel deformation amount and deformation rate.The developed model was verified by the monitoring data.The tunnel deformation amount and deformation rate after excavation were predicted by the developed models of this study.The results showed that:1)Among the EMR intensity,pulse and energy indexes,the most relevant parameters of tunnel deformation amount are the maximum peak events of EMR intensity in total events,the peak events which exceeding average energy in total events and pulse number,respectively.Their fluctuation rate are the most relevant parameters of the tunnel deformation rate.2)The three-parameter PLSR models of deformation amount and deformation rate were established by the Partial Least Squares Regression(PLSR)method.The correlation coefficients between the calculated values and the measured values of tunnel deformation amount and deformation rate were 0.838 and 0.927,respectively.It showed the effective-ness of these proposed models.3)According to the field application results,the prediction results by the three-parameter PLSR models of this study were closer to the field data than those by the unitary regression models.The prediction accuracy of the proposed models was more stable.In practical engineering,the multi-parameter model of tunnel deformation should be established by integrating the intensity,pulse and energy in-dexes of EMR,which can accurately reflect the actual deformation law of tunnel surrounding rock and promote the field application of EMR tech-nology in engineering practice.