A tunnel boring machine (TBM) is a machine used to excavate tunnels with a circular cross section through a variety of soil and rock strata. They may also be used for micro tunneling. In Japan and China, The machines used for soil are called shield tunneling machines and machines used for hard rock are called tunnel boring machine. But in Europe and USA, they are called the same name tunnel boring machine. The research we did include all of them. 更多
