For different geology,the cutting principle and configuration of shield cutters are different,in order to improve the tunneling speed,it is often necessary to change the cutters according to the applicability of cutters. For the tunnel under the lake,the high water and soil pressure and the development of the water system often lead to the poor stability of the face,the failure of the cutter head seal,and the difficulty of maintaining pressure by air pressure. In order to solve this problem,this paper makes a systematic analysis of the construction process of shield tunneling through rock strata,half-soil-half-rock strata and sand soil by relying on the long distance tunnel undercrossing Xuanwu lake project between Xinzhuang station and Jimingsi station of Nanjing metro line 3.The results show that the mud wall protection method can block the influence of groundwater and the SANSON pressure retaining system can effectively ensure the pressure stability during the replacement of shield cutter head.
cutting tool replacement
mud wall protection