Support Mechanism And Engineering Application Of Double-row Micro-pile In Deep Foundation

The double-row micro-pile composite soil nailing wall support is a new type of composite support which controls the foundation pit deformation and ensures the smooth construction of the project by using the advantages of double row micro-pile,anchor rod and soil nail.Care style.Based on the numerical simulation of FLAC3 D,it is concluded that the support scheme system constrains and restricts the displacement and deformation of the foundation pit to a certain extent,based on the foundation pit support of a residential building in prosperous area of Zhengzhou city.The main work of this paper is as follows:(1)On the basis of expounding the research and development of micro-pile at home and abroad,the paper analyzes the mechanism and construction technology of double-row micro-pile composite soil nailing wall,and explains its frequent occurrence of microDestruction of the body,destruction of the body and the destruction of the four kinds of damage model;(2)The most dangerous section slope modeling is selected,and the deformation of the foundation pit,the vertical stress and the shear strain state are numerically simulated.The maximum total displacement of the foundation pit is in the lower part of the slope.The maximum vertical stress Which is mainly distributed in the lower left corner of the bottom of the foundation pit.The maximum value of the shear stress of the foundation pit is distributed in the middle of the foundation wall.(3)The maximum axial force of the soil nail and the anchor bar appears on the middle and upper anchor,and the maximum deformation of the prestressed anchor is mainly distributed at the free end.The maximum deformation value of the soil nail is located at one end near the side wall of the foundation pit.(4)The maximum deformation of double-row micro-piles is mainly distributed in the top and middle of the outer micro-pile.The maximum value is mainly distributed in the middle and upper part of the outer micro-pile,the bending moment of the outer piles is larger than that of the inner piles.The minimum value of the axial force is mainly distributed in the middle of the inner pile and finally presents the segmentation.The maximum value of the shear force is mainly distributed in the middle and lower part of the outer pile.(5)The results of engineering simulation and its settlement monitoring value areanalyzed and compared.The results show that the theoretical analysis and settlement monitoring results are in good agreement with each other.It is proved that the supporting system is feasible and safe for practical engineering,and it also provides a scientific basis for design and construction.