大断面异形盾构穿越上软下硬地层施工技术研究  

Research on Construction Technology of Large Cross Section Special-Shaped Shield Passing through Upper Soft & Lower Hard Strata

作　　者：姚任行 YAO Ren-xing(Ningbo Rail Transit Group Co.,Ltd.,Ningbo 315101,China)

机构地区：[1]宁波市轨道交通集团有限公司,浙江宁波315101

出　　处：《中国市政工程》2024年第3期116-120,126,160,共7页China Municipal Engineering

摘　　要：依托宁波市轨道交通某异形盾构隧道区间项目,研究了在上软下硬黏性土层中大断面异形盾构施工中土体改良等施工技术控制措施。结合以往异形盾构施工出现土仓流动性差、排土不畅等问题,在施工中分3个阶段对土体改良措施进行优化调整,发现泡沫改良剂的加入可有效消除异形盾构刀盘切削盲区和不良土层对出土的影响,并且有效降低总推力、刀盘扭矩,提高掘进速度。通过关键点位(盲区及刀盘)的少量改良孔对土体进行改良,可在控制泡沫等改良剂使用量的情况下有效增强土体改良效果,并且显著提升工效。Based on a special-shaped shield tunnel section project of Ningbo Rail Transit,the construction technology control measures such as soil improvement in the construction of large section special-shaped shield in the upper soft and lower hard cohesive soil layer were studied.Combined with the problems of poor liquidity of soil bunker and poor soil discharge in the previous special-shaped shield construction,the soil improvement measures were optimized and adjusted in three stages during the construction.It was found that the addition of foam modifier can effectively eliminate the impact of the cutting blind area of the special-shaped shield cutter head and the adverse soil layer on the excavation,effectively reduce the total thrust and cutter head torque,and improve the excavation speed.Soil improvement through a small number of improvement holes at key points(blind area & cutterhead) can effectively enhance the effect of soil improvement while controlling the amount of modifiers such as foam,and significantly improve work efficiency.

关 键 词：大断面 异形盾构 土体改良 工效 

分 类 号：U455.43[建筑科学—桥梁与隧道工程]