Research And Application On A New Detachable Anchor Device And The Detection Method For Static Load Detection Of Pile Foundation

This paper mainly studies a new type of detachable anchoring device for static load detection of pile foundation and its detection method.Firstly,a new type of detachable anchoring device suitable for prefabricated pipe piles is researched and developed.Using numerical simulation method,the new anchoring device is refined finite element modeling and analysis according to the initial design size.On this basis,the device was processed and manufactured,and its ease of use and reliability were verified through actual engineering pile testing.In view of the problems found in practical applications,the key design parameters of the device were optimized by further numerical simulation methods.The specific work is as follows:（1）Introduce the history and development of pile foundation inspection methods at home and abroad,and summarize the research and application status of static load test methods and test equipment for pile foundation inspection at home and abroad.（2）In view of some of the shortcomings of the welded anchor pile method in the static load test,a new type of detachable anchoring device suitable for prefabricated pipe piles has been researched and developed.The design ideas and operation methods of the anchoring device are introduced.Trial design of the anchoring device was carried out,and the value range of the main design parameters was preliminarily determined:the thickness t₁of the semicircular ring plate can be 18mm,20mm,25mm,the thickness of the bottom plate of the semicircular ring anchoring fixture t₂can be 18mm,20mm,25mm,and the thickness of the rib plate t₃It can be 12mm,14mm,16mm,the top and bottom plate thickness t₄of the tensile anchor box can be16mm,18mm,20mm,and the web thickness t₅of the tensile anchor box can be10mm,12mm,14mm.（3）Apply the finite element software ABAQUS to establish the finite element model of the test design anchoring device,and carry out the static ultimate bearing capacity analysis.According to the analysis results,it is finally determined:the thickness of the semicircular ring plate t₁is 20mm,and the thickness of the semicircular ring anchoring fixture bottom plate t₂is 20mm,the rib thickness t₃is14mm,the top and bottom plate thickness t₄of the tensile anchor box is 16mm,and the web thickness of the tensile anchor box is t₅=10mm.According to the above dimensions,the anchoring device is processed and manufactured.（4）Through the application of the anchorage device in the actual pile foundation static load detection project,the reliability of the new anchorage device is verified.Compared with the traditional welding anchor pile detection method,the anchorage device and detection method do not need to deal with the pipe pile head,and do not need to carry out welding operation,which has the advantages of simple and fast operation,time-saving and labor-saving,and can be reused.In view of some problems found in practical applications,further optimize the design of the new anchoring device.By reducing the weight of the anchoring device,it is more convenient for the actual installation operation of the inspection personnel.The optimized design is mainly carried out for the lower semi-circular annular anchoring fixture.Through optimization,the weight of the anchoring device is reduced by29.4%,making it easier to use in actual pile foundation inspection.