基于分形理论和NRS-RF-Arima模型的隧道仰坡安全性评价  

Safety evaluation of tunnel front slope based on fractal theory and NRS-RF-Arima model

作　　者：郭子飞 GUO Zifei(China Railway First Group Co.,Ltd.,Xi'an 710054,China)

机构地区：[1]中铁一局集团有限公司,陕西西安710054

出　　处：《甘肃科学学报》2025年第1期106-112,共7页Journal of Gansu Sciences

摘　　要：为合理评价隧道仰坡安全性,以仰坡地表变形监测结果为基础,先利用分形理论的V/S分析法开展仰坡安全性初判,即初步判断隧道仰坡的安全状态及变形发展趋势,再利用邻域粗糙集理论、随机森林法和Arima模型构建隧道仰坡变形的误差修正预测模型,并通过变形预测结果评价仰坡安全性的发展趋势。实例分析结果显示:通过V/S分析,得到隧道仰坡变形的Hurst指数均大于0.5,说明其变形呈持续增加趋势,且变形维数D在1.0~1.5之间,可知隧道仰坡目前处于安全状态;经仰坡变形预测,可知隧道仰坡变形仍会进一步增加,并无收敛趋势,与趋势判断结果一致;综合二者结果可知,隧道仰坡目前虽处于安全状态,但其变形趋于不利方向,后期安全性具减弱趋势,应加强监测及支护,以保证隧道进洞安全。In order to reasonably evaluate the safety of the tunnel front slope,based on the monitoring results of surface deformation on the front slope,the V/S analysis method of fractal theory is first used to conduct preliminary safety assessment of the front slope,that is,to preliminarily determine the safety status and deformation development trend of the tunnel front slope.Then,the error correction prediction model of the tunnel front slope deformation is constructed using neighborhood rough set theory,random forest method,and Arima model,the safety development trend of the front slope is evaluated through the deformation prediction results.Example analysis shows that through V/S analysis,the Hurst exponent of tunnel front slope deformation is greater than 0.5,indicating a continuous increasing trend of deformation,and the deformation dimension D is between 1.0 and 1.5,which means that the tunnel front slope is currently in a safe state.At the same time,through the prediction of the deformation of the front slope of the tunnel,it is found that the deformation of the front slope will continue to increase without a convergence trend,which is consistent with the trend judgment results.Based on both results,it can be concluded that although the front slope of the tunnel is currently in a safe state,its deformation tends to develop in an unfavorable direction,and its safety tends to weaken in the later stage.Therefore,monitoring and support should be strengthened to ensure the safety of tunnel entry.

关 键 词：隧道仰坡 V/S分析 安全性评价 发展趋势 变形预测 

分 类 号：U456[建筑科学—桥梁与隧道工程]