盾构下穿高铁桥群钻孔灌注桩隔离加固技术  

Drilling Piles Isolation and Reinforcement Technology for Shield Driving Through High-speed Railway Bridge Group

作　　者：李杰[1] 

机构地区：[1]四川建筑职业技术学院

出　　处：《公路》2018年第1期262-270,共9页Highway

摘　　要：针对盾构近距离下穿高铁桥群可能引发的桩基下沉、运营安全受到影响等问题,依托某地铁盾构区间穿越京沪高铁桥群桩基工程案例,对盾构施工前的桩基加固必要性和具体加固方案进行了模拟分析与研究。基于Midas GTS软件建立数值模型,对有无隔离桩加固两种工况下的高铁桥群承台沉降、桩基位移等进行对比分析,验证了盾构施工前进行桩基加固处理的必要性。在论述隔离钻孔灌注桩隔离加固方案可行性的基础上,经研究分析得出结论,桩基加固过程中,采用分批次施工处理,可有效降低施工对高铁桥群结构的影响;采用对称跳孔成孔技术,可以在分批次的基础上进一步、大幅度降低影响;工程施工实际数据与施工前的预估数据比较吻合,且均未超过允许值,加固方案可行且作用明显。To deal with the problems for shield driving through high-speed railway bridge group, such as pile foundation sink and affecting operation safety, the case of shield driving through Beijing-Shanghai high-speed railway bridge pile foundation is taken as the study object, simulation analysis and research for the pile foundation reinforcement necessity and specific reinforcement program are made before shield construction. The settlement of pile cap and displacement of pile foundation are compared when with and without isolation piles reinforcing based on the model established by Midas GTS. The significance for pile foundation reinforcement treatment before shielding construction is verified. After demonstrating the feasibility of isolating the drilled piles scheme, following conclusions are drawn： the influences of construction to high-speed bridge group structure could be effectively reduced using the measures of batch processing; symmetrical hole jump technology is an effective construction method which can further reduce influence on the basis of batch processing; and the actual construction data matches well with the predicated value before construction, and don＇t exceed the allowable value which proves that reinforcement scheme is feasible and with obvious effect.

关 键 词：盾构 高铁桥群 近距离下穿 加固 分批次施工 技术 

分 类 号：U445.72[建筑科学—桥梁与隧道工程]