Research on Integrity of Cement-flyash-gravel Pile and Bearing Capacity of Its Single Pile(Composite Foundation) of Subgrade

Certain thickness of concrete in the bottom of cement-flyash-gravel pile of subgrade of Wuhan-Guangzhou passenger dedicated line is disintegrate because of the construction technology and water at the bottom of hole. The thickness of disintegrated concrete is detected by the reflected wave method and its properties are analyzed,in which the construction quality of concrete of pile is decided. By static load test,the bearing capacity of single pile and the bearing capacity of single pile composite foundation are determined.