摘要
随着土压平衡盾构的广泛推广和应用,其地层适应性也越来越强,但盾构机在一些特殊地层中掘进时,渣土无法满足盾构施工对渣土流塑性的要求,易造成刀盘结饼、掌子面压力不稳定、刀盘磨损严重等问题。泡沫渣土改良技术是保证施工安全、顺利进行的关键技术之一。本文针对两种工程现场常用的泡沫进行泡沫基础性能试验,并以南昌地铁3号线盾构区间为工程背景,针对该区间砾砂地层进行改良渣土坍落度试验,对不同注入率和不同发泡剂的改良效果进行分析。研究发现,两种泡沫剂的建议使用浓度为3%;渣土流动性随泡沫注入率的增大而提高。在试验所用土样条件下,建议施工时使用的泡沫注入率为20%~30%。
With the wide application of the earth pressure balance shield,the formation adaptability requirements of the shield construction are getting higher.When the earth pressure bulance shield machine is constructed in some special strata,the soil cannot meet the requirements of the flow and plasticity of the muck,and it is easy to cause problems such as the clogging,unstable pesure on the face and serious wear of the cutter.Slurry soil conditioning with foam is one of the key technologies to ensure safe and smooth construction.In this paper,the basic performance of two foaming agents commonly used in projeets was investigated.And based on the shield section of Nanchang Metro line 3,the slump lests on slurry soil conditioning of gravel sand layer were crried out,and the improvement efet of diferent grouting ralte and diferent forning agent is analyzed.The results show that the reconmended concentration of the two forring agents is 3%;the fluidity of the conditioned soil increases with the increase of the fouming rate.For the grvel sand layer used in this paper,it is recomended to use a foam grouting rate of 20%-30% during construction.
作者
连小涛
LIAN Xiaotao(Urban Rail Tafe Engineering Branch Co.,Lad.of CTCE Group,Hefei Anhui 230023,China)
出处
《铁道建筑技术》
2020年第4期14-17,51,共5页
Railway Construction Technology
基金
国家自然科学基金资助项目(51578460)。
关键词
土压平衡盾构
渣土改良
砾砂层
试验
earth pressure balance shield
soil conditionig
gravel sand layer
test
作者简介
连小涛(1986-),男,甘肃靖远人,工程师,主要从事地下工程方面的工作,E-mail:510757984@qq.com。
