Distributed detection and bearing mechanism of rock-socketed piles

On the basis of BOTDR-based distributed optical fiber sensing technology, the bearing characteristics of rock-socketed piles, with working load on pile top, in the overlaying soil at a certain depth are studied, and the development of the pile lateral friction and the socket axial force is also analyzed. The results show that owing to the distributed features of BOTDR-based distributed optical fiber detection technology, an effective grasp is achieved of the bearing capacity and load transfer mechanism of rock-socketed piles. Moreover, the pile lateral friction of the upper soil layer bears most of the load of rock-socketed piles in the overlaying soil at a certain depth, while the pile bottom takes only a small proportion of the load. Therefore, the design of rock-socketed piles should be considered as that of friction piles or end-bearing friction piles. It is also found in the study that due to the growing number of socket rock cracks, part of concrete slurry is poured into socket rock cracks during the process of concrete filling, which accordingly improves socket bearing capacity. Thus, the pile lateral friction of the upper part of socket is intensified.