上软下硬地层超大直径盾构机选型及适应性分析

Type Selection and Adaptive Analysis of Super Large-Diameter Shield Machine in Upper-Soft and Lower-Hard Strata

以实际工程为依托,结合地质和水文条件,对上软下硬复杂地层超大直径盾构机进行选型分析,并基于工程特点,对盾构机刀具、管片拼装机、泥浆环流系统进行针对性设计。采用有限元软件对盾尾强度和刚度进行校核,同时对超浅覆土段施工提出控制措施。结果表明:采用泥水平衡盾构机更适应本工程地质及水文条件,针对性设计能有效增加刀具寿命,改善刀盘中心区域渣土流动性,防止泥饼形成;盾尾强度、刚度均能满足设计要求;通过配置双舱气垫式压力平衡系统、双回路Samson自动保压系统、二次双液补浆系统能有效规避地表被击穿及盾构机管片上浮问题。

Based on actual engineering,combined with engineering geology and hydrological conditions,this paper selects the type of super large-diameter shield machine in the upper-soft and lower-hard complex strata,and according to the characteristics of the project,the shield machine tool,segment assembly machine,mud circulation system are designed in a targeted manner.The strength and stiffness of the shield tail are checked using finite element software,and control measures are proposed for the construction of the ultra-shallow soil covering section.The results show that the mud-water balance shield machine is more suitable for the geological and hydrological conditions of the project.After targeted design,it can effectively increase the tool life,improve the fluidity of the muck in the central area of the cutter head,and prevent the formation of mud cakes;The strength and stiffness can meet the design requirements.Through the configuration of double-chamber air cushion pressure balance system,double-circuit Samson automatic pressure maintenance system,and secondary double-liquid grouting system,the problems of ground surface breakdown and shield machine segment floating can be effectively avoided.