Full face tunnel boring machine for deep-buried roadways and its key rapid excavation technologies

To overcome the problem of low penetration rate of hard rock roadways in deep-buried coal mine,the engineering environment of deep-buried coal mine roadways excavation and technical features of tunnel boring machines(TBMs) were comprehensively investigated. The technical index of deep-buried coal mine TBM was established through the feasibility researches of excavating deep-buried coal mine roadways by using TBMs,then the deep-buried coal mine TBM was developed. Based on some cyclic loading-unloading rock tests which con-sidering the disturbance of TBM excavation,the quasi-static cyclic loading-unloading damage constitutive model and non-linear failure criterion were established and introduced into the numerical simulation of roadway stability study. Through numerical simulation and site monitoring,the mechanical response mechanism of roadway sur-rounding rocks under TBM rapid excavation was revealed,and the roadway support pattern and technique which fulfill the requirements of TBM-excavated coal mine roadways were proposed and verified in site applications. To overcome the problems of restricts on the lifting capacity of vertical shaft,limited working space of underground working sites and frequent mobilization of equipment,the techniques of TBM transportation,assembly as well as disassembly in limited space were developed,and the key techniques of TBM launching and excavation were in-novated. The problem of hard rock rapid excavation was resolved by adapting synchronous operation of excavation,supporting,lashing and auxiliary transportation. Finally,the research results were verified by industrial tests which implemented in the overlying methane drainage roadway of 1413A longwall panel in Zhangji coal mine,Huainan,China. The test results indicated that in excavating deep-buried coal mine roadways by using TBMs,the average penetration rate reached up to 404 m / month and the highest penetration rate was 560 m / month,which is 5 to 10 times of current penetration rate of hard rock coal mine roadways.