Development and mechanical characteristics of a recyclable self-balancing detection device

Aiming at the main problems existing in the static load tests on pile foundations, a recyclable self-balancing detection device for the bearing capacity of the pile foundations is developed. The load transfer model for the test piles under the action of a new recyclable detection structure is established, and the load transfer matrix of pile body in a layered foundation is derived. The reliability of theoretical analysis is verified by the results of three-dimensional finite element calculation in practical engineering. The working mechanism of the structure is studied based on the data of load-displacement and pile axial force obtained from the field measurements. The results show that: (1) The new structure has high assembly degree, short test period, low energy consumption and small test space requirements, and is worth popularizing. (2) The axial load-displacement curves of the pile obtained from the theoretical analytical model are in agreement with the measured results, both of which are within the allowable error range compared with those of the load box test structure. (3) The accuracy of the bearing capacity measured by the new structure is improved by 3.5%. Therefore, the theoretical model and the new structure are of great applicability and popularization value in practical engineering.