Vibrating Densification Device Development Of Rodless Drilling Unit

In the infrastructure construction Engineering, The pile foundation is widely used. According to the load transfer mechanism of pile foundation, it can be divided into the friction pile bearing, friction, the friction pile cap and the pile bearing pile. Among the pile foundation, the bearing capacity of the friction pile depends on the friction which can be provided from the soil near the pile. With the increase of compactness of the soil near the hole, the friction pile and soil, the capacity will be greatly enhanced. Also, for the hole collapse and drill bit accident, The reason why is mostly because the soil is not compact, not of high density and low anti-interference capability. Current,we treat this passive after the accident,and there is no active measures of prevention measures. In view of this, this paper proposed a method which uses vibration to compact the hole soil to prevent the hole soil collapse and the drill burying accident. To improve the compactness of hole soil to enhance the capacity of the friction pile foundationOn the base analysis of the existing rodless drilling rig's structure and working principle, combined with the of compacting mechanism of soil, Having designed the excitation device and the guiding & supporting device and assembled them organicly,we make up the vibrating densification device. with the Finite Element Method(FEM), the paper has done the strength calibration of the vibrating densification device under the most severe condition. The results showed that under the severe load conditions, the vibrating densification device can meet the demand of strength and can work safely.The paper has set up two kinds of conditions of dynamics model of the vibrating densification device, deduced the mathematical model of them.Crystallized the relationship between the amplitude and the exciting force,vibrating frequency,soil rigidity,soil damp. In order to get the first twenty inherent frequency and inherent vibrating figure of the system ,the paper has ultilized the Block Lanczos algorithm of the finite element software ANSYS. The results show that: Because the weight of the vibrating densification device is mainly distributed in the guiding & supporting device,and it is of a symmetry stucture, so it come to this that three similar continuous frequencies. The inherent figure occurs mainly in the guiding & supporting board of the guiding & supporting device.The test system of rodless drilling unit was established, and the first ?1 200mm vibrating densification device of the rodless drilling unit was manufactured. And through the use of vibration analysis software DH5938 vibration test system,we got the acceleration curve, velocity curve and amplitude curve from the guiding & supporting board of the guiding & supporting device. Correctness of the design and manufacture was proved by the experiment. At the same time, the existing problems were analyzed by the test. Experimental results show the Correctness of the design and manufacture.