Abstract: In order to develop a new offset blade cutter ring which is suitable for the construction condition of the tunnel with small turning radius, the paper carries out the following research work: First, based on the principle of abrasive wear, the side force model of the CSM cutter ring, the rock breaking mechanism of the edge hob, and the wear prediction formula are studied. Second, by conducting a hob rock cutting experiment, a contact force model between the cutter ring and the rock is established. Third, the force condition of the edge cutter ring in the turning section is analyzed, and the offset blade cutter ring is designed. At last, in the construction condition of the small turning radius tunnel in Wendeng of Shandong province, the industrial tests of conventional cutter ring and offset blade cutter ring are carried out. The conclusions are drawn as follows: 1) When TBM is tunneling a straight tunnel, the lateral force exerted by the edge hob can not be ignored, which is related to the contact area of the cutter ring with the rock and the pressure. 2) During straight tunneling, the rock on the outside of the edge hob is hardly broken, while the inside of the edge hob has "scratching shear effect" on the rock, and the lateral force of the cutter ring exerted by the inside is much greater than the outside. 3) The force exerted by inside of the cutter ring at the turning section has badly deviated from the normal pressure direction, which accelerates the wear on the inside of the edge hob cutter ring. 4) When the tunneling distance reaches 145.43 m, compared with the conventional cutter ring, the wear rates of the offset blade cutter ring of No. 19 and No. 20 are decreased by 7.4% and 17.5% respectively. So the offset blade cutter ring is more suitable for tunneling in the construction condition of small turning.

Key words: conventional cutter ring, offset blade ring, wear rate, small turning radius tunnel, TBM