The self-balancing method is a static load test method that provides reaction force by the weight of the pile body without resorting to external force. By pre-embedding the pressure cell between the piles and loading them by jacks, the bearing capacity of the whole pile can be obtained by testing the bearing capacity of the upper and lower piles.
The self-balancing method is different from the traditional stacking method and anchor pile method. This technology is to place a load box shaped according to the load capacity parameters of the pile at the bottom of the pile body during the construction process, and connect the pressure tubing and displacement measurement device to the pile At the top, after the concrete is cured to the standard age, the bottom high-pressure oil pump is used to press the bottom load box to obtain the bearing capacity of the pile end and the total friction resistance of the pile side.
The self-balancing test method uses the resistance of the pile as a reaction force to avoid a huge reaction force device. The device is simple, saves time and effort in preparation, and can save a lot of test costs.
When using engineering piles for testing, the load box position will form a broken pile after loading, which is not suitable for treatment. The position of the load box balance point needs to be estimated. The friction force of the upper pile body and the friction force and end resistance of the lower pile body are not easy to balance. At the time, the negative friction is measured on the upper part of the load box, which is different from the actual situation and needs to be adjusted according to experience.
It can be seen from the above analysis that various pile foundation detection technologies have certain limitations due to their respective theoretical assumptions and various factors. Therefore, it is necessary to make full use of the strengths of various methods to solve practical engineering problems.