On the construction appraisal scene of a certain single building in Chengdu, Sichuan, relevant foundation piles all are below the floor. This building cracks due to the earthquake, the crack appears on the fourth floor of the basement, which is also the bottom floor of the this building. The test scheme is to open this floor, and after the foundation pile position is located, drill cores on the pile surface, and conduct borehole television test.
Take a typical pile among them as an example. This pile diameter is 1100mm, the pile length is 16.8m, and it is located at the center of the whole building. The coring hole is 200mm to the north of the pile center and the borehole diameter is 90mm. The data describe that this foundation pile is C30 concrete, rotary digging pile and the construction technology is underwater casting.
Field pictures of the project
RSM-DCTD borehole television tester of Wuhan SINOROCK is used in this test, and borehole imaging test is conducted for this pile in accordance with the Technical Specification for Testing Method with Video Monitor through the Hole of Foundation Pile CECS 253:2009 of China Association for Engineering Construction Standardization.
It is found in the test process that a large amount of suspected aggregates do not meet the requirements, and a large amount of cracks and gaps are found. In combination with the incompleteness of lots of coring samples of this pile, this pile is judged to be Class IV. 
