Study And Application On Vertical Load Transefr Meehanics And Bearing Capacity Of Rock-Socketed Piles

The rock—socketed piles are one of the most used pile forms in constructions of bridges,ports and buildings in our country.How to rationally determine the vertical load—bearing capacity of rock—socketed piles is one of the most important questions in engineering.In this paper,the the load—bearing mechanics and the methods of determining the vertical load—bearing capacity of rock—socketed piles have been deeply system studied by load test and finite element method,that has important signification in theory and engineering.Firstly,the load—bearing mechanics of rock—socketed piles and every calculating mode and effecting factors of the shaft resistance and the end resistance of piles were discussed and analyzed,and the actual methods of determination the vertical bearing capacity of rock—socketed piles were analyzed.On the base of analysis and contrast of data on load-test,one 3-D elastic-plastic finite element model for simulating the load—bearing mechanics and the vertical bearing capacity of rock—socketed piles have been presented,in this finite element model the hardening character of geotechnical materials and shear stress limit(?),tangential stiffness and max elastic slip of pile/rock or soil interface were considered.The load—bearing mechanics and percentages of the shaft resistance and end bearing capacity under two typical rock(hard and soft rock)and five different socketed depth and effect of the pile bottom sediment were analysis by the presented finite element model.The numerical analyses indicated that the shaft resistance characters were influenced by strength and elasticity modulus of rock mass around piles.The load—bearing characters of the rock—socketed piles constructed in hard rocks were dominated by the pile resistance behavior along the concrete-rock interface. Furthermore,the pile resistance along the concrete-rock interface can be greatly influenced by the deformation characteristics pile/rock interface.Socketed depth influences the bearing properties.The shorter socketed depth,the more strength load-bearing of pile end.and the bearing capacity were effected clearly by the pile bottom sediment. Obtained conclusions and rules provided basis to relational design for actual engineering. To combine analysis and contrast of data on load-test,some reasonable construction suggestions were presented on the rock—socketed piles studied in this paper.