A new type of multi-dimension squeezed penetration piling machine is a piling machine for forming multi-grade squeezed pile.

By the static loading test of the large diameter bored cast-in-place pile,in which stressometers and deformeters are inbuilted at the pile s differrnt positions such as the bottom,the interfaces for soil layers along pile and so on,the loading transmission mechanism,the regulations of axial force and the skin friction of pile are analyzed.

The application of grouting reinforcement method in quality control of large-diameter cast-in-situ pile;

high strain, low strain and sonic transmission, including their characteristics and records of test on large diameter in-situ piles, with the conclusion of the merits and weakness of each method.

The testing results indicate that the bearing capacity of a single large diameter in-situ pile with problems could be significantly improved by pile-bottom pressure grouting.