Study On Identification Technology Of Surrounding Rock Loose Zone In Shale Tunnel

Tunnels play a critical role in the construction of transport infrastructure.During tunnel planning and construction,stability is one of the most important criteria needs to be measured due to its significant impact on safety and security.Out of many factors that affect tunnel stability,the loose zone of surrounding rock(LZSR)could be important.Great achievements have been made on researches of LZSR stability across the world.Nevertheless,the outcome of their studies cannot be simply applied in all cases due to the variation of geographical conditions.It is still important to discuss and come up with other possible approaches that may suits better for the local environment.To facilitates the research,rock samples have been extracted beforehand from various depths within the LZSR of Second Laomuyu Tunnel,located in Zhangjiajie.This research implements the following approaches to determine the range of LZSR:Use of Ground Penetrating Radar(GPR)to detect geographical conditions at different locations within LZSR.This approach is widely accepted by experts around the world.Use of Matlab image processing tool to find the correlation between the area of fissures in the surface of rock samples and their respective depths.Use of sound wave test to find the correlation between the speed of sound waves inside rock samples and their respective depths.Use of uniaxial compression test to find the correlation between the compressive strength of rock samples and their respective depths.The correlation models derived from method 2,3 and 4 would be further analysed to determine the range of LZSR.