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.

Based on Mindlin stress solution, the calculating method of additional stress in foundation soil for any distribution form of the skin friction of pile is deduced in this paper, and the settlement problem of single pile is analyzed.

The bearing performance of pile is studied, including uplifting displacement, load transfer, and development of side resistance.

The post-grouting technique for the bored pile construction can make the cement paste penetrate, fill and compact under the high pressure, and produce the physical and chemical consolidation with the settled materials, clay skin, and the soil body around the pile and on the tip of pile, increasing the side resistance and tip resistance, and further increasing the capacity of the single pile.

The developing degree of side resistance is well corresponding to the relative displacement between pile and soil.

These factors,which include slurry s preparation,circulation,depuration and so on,would influence drilling speed,bore quality,exertion of pile shaft resistance and base resistance.

According to the variation of shaft resistance around piles simulated by software ANSYS,we regard that short piles(engineering piles) will affect shaft resistance distribution around long piles(upright post piles).

The shaft resistance along pile under inclined load is greater than that of pile under lateral load within a certain depth below ground surface.

Abnormal effect of skin friction of bored pile in Shanghai;

Property of slurry has direct impact on the bearing capacity and skin friction of bored piles.

The slurry property has effect on the bearing capability and skin friction of bored pile and the different requirements of building from highway and bridge for slurry material and slurry property are discussed.