摘要
双液浆胶凝时间短,早期强度较高,能够及时填充盾尾空隙,有效防止管片上浮、错台及地表沉降。依托北京东六环改造工程,采用室内试验比较分析了水灰比、波美度对双液浆泌水率、强度等性能指标的影响。通过原型试验,探讨了注浆量、注浆压力、配合比等因素对大直径盾构隧道同步双液注浆的扩散机理及注浆效果的影响规律。研究结果表明:化学胶结时间,物理初凝、终凝时间随水灰比减小而逐渐减小;原型试验中土压力和孔隙水压力整体呈“单峰”式曲线变化;盾构隧道管片上浮量在-10~10 mm,管片错台量集中在3 mm以内,地表沉降值较小。
The double-liquid(cement-sodium silicate)grouting has short gelation time and high early strength,can fill the interspace of shield tail timely and prevent segment floating,segment misplacement and ground subsidence effectively.Based on the reconstruction project of East Sixth Ring Road in Beijing,the influence of different water cement ratio and baume degree on bleeding rate and strength were compared and analyzed by laboratory tests.The impact of grouting volume,grouting pressure,and mixing proportan on the diffusion mechanism and grouting effect of synchronous double-liquid grouting in large-diameter shield tunnel were discussed based on the prototype test.The results show that the chemical bonding time,physical initial and final setting time decrease with the reduction of water cement ratio.The earth pressure and pore water pressure curve show a single-peak change in the prototype test.The value of the segments floating varies at-10~10 mm.The amount of segment misplacement is iess than 3 mm,and the ground subsidence is small.
作者
舒计城
SHU Jicheng(China Railway 14th Corporation Mega Shield Construction Engineering Co.Ltd.,Nanjing 211800,China)
出处
《铁道建筑》
北大核心
2022年第5期117-122,共6页
Railway Engineering
基金
中国铁建股份有限公司科技研发计划项目(2021-C14)。
关键词
盾构隧道
壁后注浆
双液注浆
原型试验
管片上浮
水灰比
波美度
泌水率
shield tunneling
back-fill grouting
double-liquid grouting
prototype test
segment floating
water cement ratio
baume degree
bleeding rate
