摘要
现阶段超大断面箱涵顶进注浆施工工艺在工程建设过程中得到了广泛的应用,在进行注浆施工时先采用小口径钢管构建水平维护结构,然后再将箱涵进行顶进,最终实现大断面地下空间结构。通常在进行普通箱涵顶进施工时需要在箱涵管内部先预留注浆孔,然后再注入膨润土为主料的复合泥浆,最终可以降低泥浆套摩阻力。近些年来,国内外相关专家对顶进触变注浆作用及泥浆机理进行了更进一步的研究,通过减摩工艺对施工现场进行指导。采用此种施工技术时管幕与箱涵间存在间隙,采用正面开挖时应将间隙间保留到原状体重,但是此种情况下会有超挖现象,采用此种注浆工艺进行施工时应先解决箱涵顶进所产生的摩阻力,如果此种情况没有做好处理无法为上部管幕提供支撑力,同时大断面箱涵结构会受到运输、吊装等方面的影响,所以多会采用现场浇筑作业方式,并做好后期养护工作,在这个过程中如果没有对浆液中的水分进行控制在填充时会导致上部结构出现变形或地面沉降现象。在施工中采用钢管幕与箱涵间的缝隙并注入一定厚度的厚浆与稀浆,可以降低箱涵顶进过程中周边摩阻力并有效避免地面沉降现象,提升箱涵施工质量。
At the present stage,the jacking grouting construction technologyof super large section box culvert has been widely used in the process of engineering construction.In the grouting construction,the small diameter steel pipe is used to construct thehorizontal maintenance structure,then the box culvert is jacked and finally the large section underground space structure is realized.Usually,in the jacking construction of ordinary box culvert,it is necessary to reserve grouting holes in the box culvert pipe and then inject the composite slurry with bentonite as the main material,which can ultimately reduce the friction of the slurry sleeve.In recent years,relevant experts at home and abroad have carried out further research on jacking thixotropy grouting effect and slurry mechanism and guided the construction site through friction reduction technology.When using this construction technology,there is a gap between the pipe curtain and the box culvert.When using the front excavation,the gap should be kept to the original state,but there will be over excavation in this case.When using this grouting technology,the friction caused by the jacking of the box culvert should be solved first.If this situation is not handled properly,it can not provide support for the upper pipe curtain.At the same time,the large section box culvert structure will be affected by transportation,hoisting and other aspects,so the site pouring operation mode willbe adopted,and the later maintenance work will be done well.In this process,if the water in the slurry is not controlled,the deformation or ground settlement of the upper structure will occur when filling.In the construction,the gap between the steel pipe curtain and the box culvert and the injection of a certain thickness of thick and thin slurry can reduce the peripheral friction during the jacking process of the box culvert,effectively avoid the phenomenon of land subsidence,and improve the construction quality of the box culvert.
作者
刘新文
LIU Xinwen(Power China Harbour CO.,LTD.,Tianjin,300457,China)
出处
《智能城市应用》
2021年第2期60-63,共4页
Smart City Application
关键词
超大断面箱涵
顶进注浆
施工工艺
super large section box culvert
jacking grouting
construction technology
