earth pressure balance tbm mainly consists of cutter, anterior shield, middle shield, tail shield. it is mainly applied to less underground water, stickiness stratum of small permeate coefficient, grittiness stratum and gravel stratum, it have many functions, such as excavation advance, synchronize lining, disposable become to hole and so on. earth pressure balance tbm keeps soil mass pressure of excavation cabin, maintain relative stability of excavation facial through by accuracy control the muck displacement of excavation cabin. in order to improve the plasticity, liquidity and water tightness of soil mass, and improve the excavation efficiency of cutter, reduce cutter abrasion through by inject bubble, polymer and bentonite from cutter to excavation face. different cutter structure and cutter tool configuration, so this kind of tbm can suitable for wide and complicated geological condition.our company accumulatively has produced more than 70 sets of different types of earth pressure balance tbm, meanwhile export to the middle east, southeast asia etc. international market. the equipment cost of this type of machine and construction cost have large advantage compare with other full section tbm. it possesses excavation face stable, high efficiency construction, good safety, reliability characteristics, and it will develop to diameter upsizing and adapt big burial depth, high water pressure stratum, etc.