邻近运营铁路深基坑开挖施工技术优化及桥墩变形控制研究

Research on Optimization of Adjacent Operating Railway Deep Foundation Pit Excavation Technology and Pier Deformation Control

摘要: 锡澄运河市区段涉铁航道工程为下穿京沪铁路、沪宁城际高铁的三级航道深基坑工程，施工区域地质复杂、周边环境敏感、工期紧张，且面临铁路设备微变形控制(沪宁城际±2 mm、京沪铁路±3 mm)等严苛要求。本文以该工程为研究对象，系统分析工程地质水文特征及施工重难点，重点阐述杂填土换填、桩基施工(高低机型搭配、振动改静压)、基坑降水、土方开挖(快挖快撑、分层分区优化)、支撑拆除等关键工序的技术优化方案。结合第三方自动化监测数据，分析深基坑施工对邻近铁路桥墩的变形影响规律，提出“技术优化 + 动态监测 + 过程管控”的施工体系。工程实践表明，施工期间铁路桥墩变形零报警、工程质量优良、工期提前完成。该体系可为同类临近运营铁路深基坑工程提供技术参考和实践借鉴。

Abstract: The urban section of the Xicheng Canal railway-related waterway project is a deep foundation pit project for a class III waterway that passes under the Beijing-Shanghai Railway and the Shanghai-Nanjing Intercity High-speed Railway. The construction area has complex geological conditions, sensitive surrounding environment, and tight schedule, and faces stringent requirements such as micro-deformation control of railway equipment (±2 mm for Shanghai-Nanjing Intercity High-speed Railway and ±3 mm for Beijing-Shanghai Railway). This paper takes this project as the research object, systematically analyzes the engineering geological and hydrological characteristics as well as the key difficulties and challenges in construction, and focuses on elaborating the technical optimization schemes for key processes such as replacement of miscellaneous fill with soil, pile foundation construction (combination of high and low-level machines, vibration-to-static pressure conversion), foundation pit dewatering, earth excavation (rapid excavation and support, layered and zoned optimization), and support removal. Combined with third-party automated monitoring data, the deformation impact of deep foundation pit construction on adjacent railway piers is analyzed, and a construction system of “technical optimization + dynamic monitoring + process control” is proposed. Engineering practice shows that there were no alarms for railway pier deformation during construction, the project quality is excellent, and the construction period was completed 5 days ahead of schedule. This system can provide technical reference and practical guidance for similar deep foundation pit projects near operational railways.