摘要
泥水盾构在高渗透性砂性土层施工中泥浆的成膜质量会影响工程的安全与进度,设计室内试验研究泥浆相对密度对滤水量的影响,采用均匀设计法对不同制浆材料在砂性土层中的填充效果进行实测与回归分析。结果表明,泥浆的相对密度反应了单位体积内所能提供的用于孔隙填充的颗粒数量,是影响滤水量以及填充致密程度的首要因素;泥膜的形成质量受到制浆材料的影响,在中粗砂地层中,孔隙可以由膨润土和黏土颗粒共同填充,而对砾砂地层中孔隙较大的区域,黏土的填充效果已不再显著,主要依靠膨润土水化后形成的胶结颗粒集合进行填充;中、粗砂与含砾中、粗砂地层中宜采用的泥浆相对密度为1.20~1.25,制浆材料宜选取膨润土、黏土共同配制的新浆与原浆混合浆液。结合南京地铁某越江隧道,实际施工过程中泥浆相对密度控制在1.20~1.25,且每制备1 m3新浆,膨润土加入量为3~5 kg,施工反馈表明对应的掘进区间出浆相对密度稳定,研究成果可为现场泥浆的配置与管理提供一定参考。
A slurry infiltration apparatus was developed to study the laws of filter cake forming during slurry shield construction in high permeability and complex strata. The laboratory test was aimed at finding the influence of slurry properties and materials on filter cake forming process,during which the uniform design was used. Results show that the slurry proportion is the primary factors influencing the filter cake quality. Larger pores in gravel sand can be filled by the cementation sets after the hydration of bentonite particles. And in medium-coarse sand and gravel sand,the appropriate slurry proportion is between 1.20 and 1.25,slurry material is suitable to choose both bentonite and clay which is compound by new pulp and original pulp. According to the slurry management during construction,slurry proportion is set by 1.20–1.25 and the usage of bentonite is 3–5 kg every 1 m3 of new pulp. Feedback shows that the proportion of the original pulp is stable in the corresponding range,which is to say the filter cake is forming well and the excavation face is stable.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2015年第S1期3460-3467,共8页
Chinese Journal of Rock Mechanics and Engineering
关键词
土力学
泥水盾构
泥浆配比
均匀试验
滤水量
致密程度
soil mechanics
slurry shield
slurry materials proportion
uniform test
water filtration
compact degree
