Detection Of Geological Anomaly And Classification Of Surrounding Rocks Based On Seismic Information

Currently,the Gaoligongshan Tunnel on the Darui Railway,which has a length of 34.5km,is the longest constructing tunnel in China.The tunnel site is located at the southern end of the Hengduan Mountains in which have extremely complex geological conditions and has the characteristics of “three highs and four actives”.During the construction of the project,it is always confronted with the disaster which caused by the high temperature,rock burst,faults,water inrush,mud inrush,soft rock and so on.How to identify the size of geological anomalies and evaluate the location of it.It has been the key of the problem to ensure the rapid and safe construction in the tunnel.Thus,this paper focuses on the four typical surrounding rocks of the tunnel and analyzes the characteristics of them.After that a dynamic grading system which is focus on the surrounding rock,is established.In this paper,the main progress and results achievements obtained are as follows:(1)By studying the engineering geology and hydrogeology of the surrounding rock of the tunnel,it is researched that the lithology and physical and mechanical characteristics of the surrounding rock with geological anomalies(including the surrounding rock of the rich water,the surrounding rock of the weak broken zone,the surrounding rock of the fault crushing zone,and the landslide Interactions with faults on the surrounding rock),and the analysis of its engineering geological conditions.(2)Drawing on domestic external rock classification methods,TSP detection technology was used in geological forecasting in the study area.Combining with the actual situation of geological anomalies,seismic information based on TSP detection technology was extracted.After that,there are two methods,cluster analysis and factor analysis,are used to study the characteristic response relationship between seismic waves and the physical and mechanical parameters of surrounding rocks.Based on the relationship,a dynamic grading system of surrounding rock was established.(3)Using the established dynamic grading system of surrounding rock,the surrounding rock was identified and evaluated,and then the geological anomaly ahead of the tunnel was predicted.The predicted results show that the lower the grading level,the lower the hardness of the surrounding rock and the stronger the water richness;the higher the grading level,the higher the hardness of the surrounding rock and the weaker the water-rich;The more reflective surfaces,the worse the integrity of the surrounding rock;the less the reflective surface,the better the integrity of the surrounding rock.(4)The dynamic classification results of the four typical surrounding rocks in the study area were verified by TSP detection and actual disclosure of surrounding rock.The verification results show that for the three types of surrounding rocks,in the zone of rich water,weak fracture and fault fracture,the prediction effect of this three classification is good.the recognition effect on surrounding rocks under the influence of faults and landslides is general,but it does not affect.the overall rating reasonable.This paper provides a dynamic grading method and an analytical interpretation for the surrounding rock of the tunnel.It also provides a grading evaluation basis for the geological anomalies encountered in the continued excavation of the tunnel in the later period.The methodology,techniques and process used in this study can be referenced when studying the engineering geological problem.