Structural Design and Calculation of KTY4000 Power Head Boring Machine

The bored pile foundations of the Jiashao Bridge are constructed by the KTY4000 Power Head Boring Machine.The boring stem of the machine is driven by the power head and the boring bit is in turn rotated by the boring stem to discharge the boring slag from bored hole by the reverse circulation air lifting method.The machine is mainly composed of the power head,sliding transverse beams,boring mechanism(including chassis,rig and sealing chassis),rigging device,cabinet,hydraulic station and electric control system.The SoildWorks is used to establish models and from the ANSYS finite element calculation,it is known that the maximum stress and deformation of the rig is respectively 161.65 MPa and 2.26 mm,the maximum stress and deformation of the boring stem is respectively 173.31 MPa and 8.28 mm and the results thereof can all satisfy the design requirements.As proved by practice,the boring machine can be applied to the construction of large diameter bored pile foundations under various complicated geologic conditions.