Vibrating pile hammer and pile sinking method based on variable stiffness to avoid resonance

Abstract

The invention discloses a vibratory pile hammer achieving a resonance-free effect based on variable stiffness, and a pile sinking method. The vibratory pile hammer comprises a mass block, a stiffnessadjusting device, an excitation hammer and a first spiral spring. The stiffness adjusting device comprises a magnetic-induced stiffness block, a conductor, a rectifying circuit and a power supply. Theconductor is wound around the outer side of the magnetic-induced stiffness block, and the power supply, the rectifying circuit and the conductor are connected in sequence. When the excitation frequency of a vibratory hammer passes through the resonance frequency of a vibratory hammer-pile-foundation system, by adjusting equivalent stiffness of the magnetic-induced stiffness block, the mass blockand the magnetic-induced stiffness block serve as absorbers to restrain vibration of the vibratory hammer, and thus influences of resonance on adjacent buildings are reduced; and when the excitation frequency of the vibratory hammer reaches the working frequency, by adjusting the equivalent stiffness of the magnetic-induced stiffness block, the mass block and the magnetic-induced stiffness block serve as vibration amplifiers to enlarge the dynamic load, applied to a pile, of a vibratory pile hammer, and thus pile sinking is accelerated.

Description

technical field [0001] The invention belongs to the field of vibratory pile sinking in geotechnical engineering, and in particular relates to a vibratory pile hammer which can avoid resonance based on variable stiffness. Background technique [0002] In geotechnical engineering piling construction, the pile can be statically loaded on the top of the pile to press the pile into the soil layer, or the pile can be driven into the soil layer with an impact load on the top of the pile, but the impact load has a greater impact on the surrounding environment, so This method of impact piling is often prohibited in urban areas where there are many buildings. At present, there is also a vibrating hammer clamped on the top of the pile to drive the pile to generate a certain frequency of vertical continuous vibration. During this process, the side friction resistance of the pile and the soil and the resistance of the pile end are reduced, so that the pile is sunk into the foundation. Th...

AI Technical Summary

Problems solved by technology

[0003] In order to overcome the problem of excessive vibration in the surrounding environment due to passing through the resonance frequency of the vibrating hammer-pile-foundation system during the process of increasing the excitation frequency of the ordinary vibrating pile hammer from zero to the working frequency, and it is difficult to amplify the vibration at the working frequency To solve the problem of pile hammer vibration, the present invention provides a vibrating pile hammer that reduces the impact of resonance on the surrounding environment

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