An Identification Method For Adverse Geology In Tunnels Based On Anomaly Analysis Of Element And Mineral

Geological hazards such as inrush of clay and water,landslide and large deformation often occur during tunnel construction,which leads to safety accidents,casualties and economic losses.The occurrence of geological hazards is often related to the tunnel crossing the fault fracture zone,alteration zone,karst and other adverse geological influence areas.During tunnel construction,identify adverse geology along the tunnel is an important link in disaster prevention and mitigation of tunnel engineering.Geological analysis method can be carried out at any time without interfering with construction,which is the most basic method to identify adverse geology.However,identification of adverse geology through traditional geological analysis in tunnel relies on experience and only carries out qualitative analysis,which leads to strong subjectivity and error in prediction results,and often leads to misjudgment and omission.Abnormal changes of elements and minerals in surrounding rocks will occur in adverse geology influence areas,and this change has certain internal laws.Therefore,this paper analyzes and summarizes the abnormal characteristics of elements and minerals in rocks affected by faults,alteration zones and karst adverse geology,and quantitatively analyzes the elements and minerals in surrounding rocks by combining with abnormal data analysis methods such as geochemistry and mathematical statistics,and establishes an identification method for adverse geology in tunnels based on anomaly analysis of element and mineral.The specific results are as following:(1)The dynamic evaluation standard and method of element and mineral data anomaly of tunnel surrounding rock are established,and an identification method for adverse geology in tunnels based on anomaly analysis of element and mineral are put forward.It is the improvement from qualitative analysis to(semi-)quantitative analysis for identifying adverse geology in tunnel by traditional geological analysis method.(2)A TBM-mounted element data testing device was developed,which realized the automatic collection of surrounding rock element data during TBM rapid excavation,and provided technical support for the identification method for adverse geology in tunnels based on anomaly analysis of element and mineral.(3)The identification method for adverse geology in tunnels based on anomaly analysis of element and mineral has been successfully applied to KS tunnel of Xinjiang**Project.Through collecting and evaluating the data of elements and minerals of surrounding rock,reveals the variation law of element and mineral content during the tunnel crossing the fault fracture zone,and the characteristics of element migration and mineral transformation in the fault fracture zone,Speculates the range of mileage 142+800?860 is the closest to the fault.