摘要
在盾构施工过程中,渣土改良显得尤为关键,根据土层的差异性,改良剂的种类及其配比各有所异。成都是目前国内大范围存在砂卵石地层的城市之一,依托成都地铁13号线某区间盾构施工工程,采用水和泡沫对砂卵石土体进行改良试验研究,找到合适的泡沫改良剂及其配比,以期加快施工效率、促进盾构项目高质量发展,为后续类似工程项目提供一定的参考。研究结果表明:卵石含量(质量分数)为60%左右的无水砂卵石土体可用水和泡沫进行改良,且水的合适注入率为2%,巴斯夫泡沫注入率在60%左右;在初始相同的泡沫剂浓度下,巴斯夫泡沫性能优于国产泡沫,性能相差30%左右;浓度越高这一差异越小;以砂卵石土体坍落度为参考,泡沫性能相同的情况下,低泡沫注入率的巴斯夫改良效果优于国产泡沫,45%~60%注入率下国产泡沫的改良效果更优;坍落度在150 mm~200 mm时,砂卵石土体具有良好流塑性,国产泡沫能以更少的注入率(低5%左右)达到巴斯夫泡沫相同的改良效果。
During shield tunneling construction,soil improvement is particularly critical and varies according to the nature of the soil.Chengdu is one of the cities in China with extensive sandy cobble strata.This study focuses on a section of Chengdu Metro Line 13.Using water and foam for soil improvement experiments,the research aims to identify suitable foam additives and their proportions to accelerate construction efficiency and promote high-quality development of shield construction projects,providing a reference for similar future projects.The results demonstrate that:Sandy-cobble soil with about 60%pebble content can be improved with both water and foam,with an optimal water injection rate of 2%and a BASF foam injection rate of about 60%;At the same initial foam agent concentration,BASF foam outperforms domestic foams by about 30%,with this difference diminishing at higher concentrations;Using soil slump as a reference,with equal foam performance,the improvement effect of BASF foam at lower injection rates surpasses that of domestic foams,though domestic foams perform better between 45%to 60%injection rates;At a slump range of 150 mm~200 mm,the sandy-cobble soil exhibits good flow plasticity,with domestic foam achieving the same improvement effect as BASF foam but at a roughly 5%lower injection rate.
作者
吕松
肖海鹏
黎泽富
李昂
毛凤杰
Lv Song;Xiao Haipeng;Li Zefu;Li Ang;Mao Fengjie(China Railway No.5 Engineering Group Co.,Ltd.,Changsha Hunan 410000,China;Changsha University of Science&Technology,Changsha Hunan 410114,China)
出处
《山西建筑》
2024年第20期16-22,共7页
Shanxi Architecture
基金
长沙理工大学创新项目:地震作用下组合砂桩加固地基中孔压分布特征与扩散演化规律研究(CLSJCX23034)。
关键词
盾构施工
渣土改良
无水砂卵石土
泡沫性能
坍落度试验
shield tunneling construction
soil improvement
anhydrous sandy-cobble soil
foam properties
slump test
