hard rock double shield tbm (short for double shield tbm), also can be called telescopic shield tbm, mainly consist of cutter, main drive, anterior shield, telescopic shield, tight shield and tail shield, between the tail shell of telescopic shield and the tail shell of anterior shield telescopic hinge joint though by cylinder. this type of tbm is widely applied to much geology, it can be used at hard rock, and also can be used at soft rock, especially, can be able to pass through fault fracture zone, it is always used at mixture lithostratigraphy’s tunneling field.
according to the construction of hole paragraph’s surrounding rock condition, can realize double shield, single shield two type tunneling, in good condition surrounding rock’s stratum use double shield model, can finish excavation and segment assembling operations at the same time, thus, effectively improve the efficiency of construction; in the presence of fault and fracture’s weak surrounding rock hole section, adopts the model of single shield tunneling, through the oil cylinder hold tight segment provides driving propulsion, can ensure that the weak surrounding rock under the safety of the excavation of construction.
in domestic and international numerous project construction, our company’s double shield rock tbm display super performance and achievement, including diameter 5.75 m equipment in gansu water supply project in yinzhao no.9 tunnel construction, it create the record of tunneling 1463 m per month. this type of tbm of our company has strong adaptability to bad geological location, mainly reflected that the good adaptability of the weak surrounds rock, between ⅱ ~ ⅴ class surrounding rock, advance rate basically stable over 30 m/d. in large buried depth, high ground stress, strong convergence strata conditions, we have unique specific design can effectively prevent the machine stop work and other construction accident, and have a safe, efficient, fast construction characteristics.