Research On Application Of Prestressed Pipe-pile In Highway Bridge Foundation

After years of techonlogy development, applicability, reliability and durability of theprestressed concrete pipe-piles has a large development, but rarely used in roads and bridges,and lack of theory and design research. The relevant regulations are remaining blank. There iscontradiction between the growing engineering practice and a relatively small number ofbasic research. To promote the prestressed pipe-pile used in highway engineering, it isnecessary to study the working mechanism, computational theory, design methodology andapplication technology of the highway bridge foundation.According to the geologic characteristics and engineering requirements, this paper usetheoretical analysis and the structure model analysis to study the prestressed pipe-pile forcecharacteristics, load bearing characteristics, check the strength of the shaft crack, the sets ofprestressed concrete pipe-pile foundation system for highway bridge foundationcharacteristics. The main conclusions are as follows：(1) Prestressed pipe-pile showed the mechanical characteristics of elastic long pile. Thepile diameter and soil modulus are the main influencing factors of prestressed pipe-pile forcedeformation characteristics and bearing characteristics; The fill prestressed pipe-pile have ahigher horizontal bearing capacity than ordinary prestressed pipe pile.(2) The comparative analysis of the results of numerical simulation and the design valueof tensile strength of concrete, the result show that the prestressed pipe pile cracking strengthcan meet the requirements.(3) Recommend the use of welded connection method for prestressed pipe-pile and rigidring connected between the pipe pile and pile cap.(4) Propose a number of structural measures to enhance the lateral stability of the roadsand bridges using prestressed pipe-pile: change the constraints of pipes; improve strength andstiffness of the single pile, pile department of force plane truss and the soil in front of the pile.The results of the paper has some theoretical significance and practical value.