为解决土压盾构在地铁隧道施工过程中穿越密集建(构)筑物桩基群的难题,以宁波地铁3 号线3103 标钱仇区间盾构掘进 切削灌注桩桩基群工程为研究对象,在现有施工技术的基础上,对切削桩基施工的难点和重点技术问题进行深入研究,针对切削桩 基通过桩基群时面临的一系列问题,制定相应的技术方案。对工程实施效果中参数变化、刀具管片状态、混凝土钢筋统计和地表及 周围建筑物沉降监测结果进行分析。结果表明: 在切削桩基施工中,各方面控制相对较好,刀具没有出现较大磨损,管片没有发生 破损与渗漏,地表沉降量及建筑物沉降量在可控范围内,施工方案是可行的,采用盾构直接切削桩基具有经济、安全、对环境影响小 的优点。

The difficulties and key technical problems in the shield cutting pile foundation group of cast-in-place piles of Qianhubeilu Station-Qiubi Station Section of 3103 Bid of Ningbo Metro Line No. 3 are studied in detail based on the existing construction technology; and the corresponding technical schemes are made for a series of problems during the pile foundation group cutting. Analysis is carried out on the parameters variation, condition of cutting tool, statistics of concrete reinforcement and monitoring results of surface settlement and surrounding buildings. The analytical results show that good effects, i. e. no large abrasion of cutting tool, no crack and leakage of segment and controllable surface and building settlement, have been achieved, which indicates the feasibility and advantages (such as economical, safe and little impact on surrounding environment) of the construction scheme adopted.