Analysis and Optimization on the Causes of Cracking of Double-row Pipe Pile and Cover Joint in Foundation Pit
A double-row pipe pile pit support structure in the Pearl River Delta was found to have cracks in the cover plate developed along the direction of the pit edge during the excavation of the pit.In order to study the stress character-istics,cracking causes and crack control measures of the interaction between the double-row pipe pile and cover after the excavation of the pit,numerical simulation calculation of the project was carried out by ABAQUS finite element software,and according to different loading conditions,the stress distribution and changes in the connection between the pipe pile and the cover were analyzed,the causes of cover cracking were explored,and the improvement measures for reasonable control of cover cracking were proposed.The results show that:the severe tensile area in the cover is mainly distributed in the connection between the front surface of the front pile and the cover and the upper surface of the cover above the front pile;the maximum value of tensile stress is always located in the connection between the front surface of the front pile and the cover;the larger stress value of internal reinforcement is mainly distributed in the rear pile;the direct cause of the cover cracking is the large deformation of the front pipe pile and the extrusion of the cover by the transfer of deformation at the node connection;by adjusting the depth of the top of the pipe pile anchored into the cover by adjusting the depth of the top pile anchored into the cover and adopting two improvement measures,it can effectively reduce the stress and control the cracks.
foundation pitdouble-row pipe pilecoverfinite elementstructural connection