Study On Settlement And Bearing Capability Of Ribbed Tubular Pile With Enlarged Base

This paper introduces manufacturing and construction methods of ribbed tubular pile with enlarged base, the process and methods of static load test and also analyzes the results of the test. The paper focuses on analysis of settlement mechanism of ribbed tubular pile with enlarged base and establishes a model for settlement calculation of ribbed tubular pile with enlarged base based on elastoplastic theory.The model mainly divide the soil under the pile base into layers, firstly calculates the additional stress of each soil layer, then uses yield function of modified Cam-clay model to judge the state of the layer. If the layer is in the elastic state or the critical state of elastoplastic, Duncan-Chang Model is used to calculate deformation of the layer. If the layer is in the plastic state, Modified Cam-clay model is used to calculate the deformation. Meanwhile the methods for calculation of pile end punching settlement are also established. The punching settlement is used as the initial parameter for calculating pile shaft compression settlement. The applicability of models in this paper is verified with case histories.The paper also analyzes the bearing capability of ribbed tubular pile with enlarged base and makes contrastive analysis on bearing capability of ordinary tubular pile and that of the ribbed tubular pile with enlarged base through different ways. No matter the contrast of results of static load test and hammer blows during pile installation or the calculation results of models in this paper all prove that the bearing capability of ribbed tubular pile with enlarged base is higher than that of ordinary tubular pile under the same condition. The formula for calculation of bearing capability of ribbed tubular pile with enlarged base is also obtained.