摘要
以南京地铁某区间40m级超深联络通道冻结加固工程为背景,针对该项目的特点,提出超深联络通道冻结设计参数与冻结加固方案,开展冻结温度场与冻胀变形的全过程实测研究。结果表明:超深联络通道冻结设计参数与冻结加固方案合理可行;冻结帷幕拱顶、两侧及底端水土压力是常规联络通道的2~3倍,满足冻结帷幕强度要求的最小厚度需3.0m;使用双排冻结管冻结可满足超深联络通道加固厚度与温度要求,且交圈时间比常规联络通道提前5d左右,成冰公式不适用于计算双排冻结管冻结帷幕平均温度,建议可用体积法;40m级超深联络通道初始水土压力为0.3MPa左右,是常规联络通道的2~3倍,需多次卸压,方可满足要求;冻结法施工引起的地表竖向位移变化可分为钻孔施工、积极冻结、开挖与维护冻结与自然解冻融沉4个阶段;超深联络通道的地表冻胀影响范围为联络通道埋深的1.15倍,基本符合45°扩散角的影响范围。
Based on the freezing reinforcement project of 40m ultra-deep contact channel in a certain section of Nanjing Metro,aiming at the characteristics of the project,the freezing design parameters and freezing reinforcement scheme of ultra-deep contact channel are put forward,and the whole process measurement of freezing temperature field and frost heave deformation is carried out.The results show that the freezing design parameters and freezing reinforcement scheme of the ultra-deep contact channel are reasonable and feasible.The water and soil pressure on the vault,both sides and the bottom of the freezing curtain is 2~3 times that of the conventional contact channel,and the minimum thickness to meet the strength requirements of the freezing curtain needs to be 3.0m.The use of double-row freezing pipes can meet the requirements of the thickness and temperature of the ultra-deep contact channel reinforcement,and the intersection time is about 5 days earlier than that of the conventional contact channel.The ice formation formula is not suitable for calculating the average temperature of the double-row freezing pipe freezing curtain,and it is recommended to use the volume method.The initial soil and water pressure of the 40m ultra-deep contact channel is about 0.3MPa,which is 2~3 times that of the conventional contact channel.It is necessary to relieve the pressure many times to meet the requirements.The change of surface vertical displacement caused by freezing method construction can be divided into four stages such as drilling construction,active freezing,excavation and maintenance freezing,natural thawing freezing and thawing settlement.The influence range of surface frost heave of ultra-deep contact channel is 1.15 times of the buried depth of contact channel,which basically conforms to the influence range of 45°diffusion angle.
作者
裴浩东
朱俊
陈佳
杨平
张婷
PEI Haodong;ZHU Jun;CHEN Jia;YANG Ping;ZHANG Ting(College of Civil Engineering,Nanjing Forestry University,Nanjing,Jiangsu 210037,China;China Shipbuilding NDRI Engineering Co.,Ltd.,Shanghai 200090,China;China Railway No.5 Engineering Group No.6 Engineering Co.,Ltd.,Chongqing 400000,China)
出处
《施工技术(中英文)》
2025年第10期77-86,共10页
Construction Technology
基金
国家自然科学基金(52178337)。
关键词
地铁
联络通道
冻结法
体积法
温度场
变形
subways
contact channel
freezing method
volume method
temperature field
deformation
