Abstract：The load transmission property of large-diameter bored cast-in-situ deep and long pile in different soil layers under vertical load is analyzed on the basis of measuring data of static load test and pile stress measurement in Changzhou viaduct road project I. The test pile is loaded to destruction，which can supply valuable project reference to further studying bearing capacity of larger-diameter bored cast-in-situ long pile. The study indicates that the bearing capability of pile bottom in deep soil layer accounts for lower proportion than skin friction；and the Q-s curves of large-diameter bored cast-in-situ long pile show steep drop type，especially with a significant inflection point. Skin friction and tip resistance of the pile have mutual influence on each other and don¢t display simultaneously；and the same situation also exists in side friction in soil layer，which demonstrates that the above soil layer first reaches the limit state；and then the lower soil layer. Burying depth has significant influence on side friction of soil layers around pile which has similar physical mechanical property and some values about side friction have great difference to recommendation value of the reconnaissance report according to measuring data. The load transmission curves of soil layer (1) and soil layer (3) correspond to process-softening model，and the load transmission curves of soil around pile bottom correspond to bilinear rigid model，which demonstrates that side friction of above soil layers is weakened to some degree for the soil layers have tendency to be destroyed by shearing；and a great deal of tip resistance of the pile is not displayed under vertical load.
