Model Test of Large Beam-Type Pile Cap and Simplified Method to Calculate Midspan Deflection
In the reconstruction project of a corridor,large beam-type pile caps are applied.This study investigates the mechanical property of this type of pile caps under varying beam depth to span ratios.1∶10 scale-down models were prepared,accompanied with finite element simulation,to analyze the load bearing behavior,failure mode and cracking of the pile caps.The result indicates that when loaded at midspan,the beam-type pile cap sequentially undergoes a linear elastic stage,a crack propagation stage and a yielding stage.In the linear elastic stage,the cross-sectional stress distribution does not comply with a plan assumption,and the influence of shearing effect on the structural deformation should not be neglected.The model finally succumbed to bending failure.The dominant cracks are the bending and oblique cracks at midspan.The smaller the span to beam depth ratio,the greater the shear stiffness of the beam-type pile cap.To examine the influence of shear effect on the deformation of beam-type pile cap,a simplified method to calculate the midspan deflection of the beam-type pile cap is proposed,and the values calculated by the method are compared with the code and test values.It is shown that in the crack propagation stage,there is a big difference between the code and test values,but small difference between the values gained by the proposed method and test values.The method can be used to initially predict the midspan deflection of the beam-type pile cap in the linear elastic and crack propagation stages.
beam-type pile capshearing effectmechanical propertymidspan deflectioncalculation methodmodel testfinite element method
万方数据
维普
