Experimental Study And Engineering Application Of Anti-floating Underreamed Anchor

With the improvement of urbanization level in China,the urban population is increasing year by year,resulting in more tension in the urban area.In the process,people gradually shifted their perspective to the use of underground space,and many residential buildings,commercial centers and office buildings with basements were built.The effective use of underground space in the urban development space at the same time,due to groundwater water buoyancy generated by the building,the upper structure cracking,tilt,collapse of the floating accidents frequently occur,and overall construct technology research has become an important topic in the field of geotechnical engineering.This paper focuses on the static load test and the engineering application of the anti-floating underreamed anchor,and the study includes the following main contents:(1)On the basis of summarizing and analyzing the current situation of the theory and technology of the anti-floating underreamed anchor,the paper points out the deficiency of current research.(2)By analyzing the force mechanism of the anti-floating underreamed anchor,the force failure mode and pre-stressing characteristics of the anti-floating underreamed anchor are summarized.Three dimensional simulation software is used to build the basement group anchor calculation model.Interaction of group anchors in the deep excavation are find during the research.(3)Through the analysis of three groups of anti-floating underreamed anchor test,the study found that the bolt load-displacement curve and elastic-plastic displacement has certain law,when the load is not more than 50% of the ultimate load,bolt load displacement curve of the present development trend of certain linear,elastic deformation of the linear elastic performance significantly;When the load is more than 50% but less than 70% of the ultimate load,the bolt load displacement curve of began to present a nonlinear trend,change of elastic deformation of the slope,the plastic deformation began to increase rapidly;When the load is more than 70% of the ultimate load,elastic deformation increases,and plastic deformation are increased,anchor displacement increases,load-displacement curve showed obvious nonlinear characteristics.(4)Combination of Zhengdong new district underground garage parking anti-floating underreamed anchor project,this paper introduces the construct of anti-floating underreamed anchor and construction methods and requirements.This paper has reference value for the application of anti-floating underreamed anchor t in engineering.