A variable frequency vertical cyclic loading device that can apply complex load forms

Abstract

The invention relates to a variable-frequency vertical cyclic loading device capable of applying a complicated loading mode, and aims at providing a variable-frequency vertical cyclic loading device which is capable of applying the complicated loading mode, simple in structure, low in cost and more in loading time number. According to the technical scheme, the device is provided with a model box and a model pile vertically fixed into the model box, the upper end of the model pile is connected with a torque loading mechanism, and the torque loading mechanism is provided with a gravity changing mechanism and a first balancing weight; the gravity changing mechanism is fixed to the ground through a steel support, one end of the gravity changing mechanism is rotatably connected to the steel support through a horizontally-arranged rotating shaft, the gravity changing mechanism is connected with the upper end of the model pile through a first steel wire rope and a connecting lantern ring, the first steel wire rope is hung on a first pulley arranged above the gravity changing mechanism, the gravity changing mechanism is further connected with the first balancing weight through a second steel wire rope, the second steel wire rope is hung on a second pulley arranged above the gravity changing mechanism, and the first pulley and the second pulley are both installed on the steel support.

Description

technical field [0001] The invention relates to a frequency-variable vertical cyclic loading device capable of applying complex load forms. It is suitable for single pile model test of single point vertical reciprocating cyclic loading. Background technique [0002] Pile foundation is one of the most widely used foundation structures in land civil engineering, and it also has great application potential in marine engineering (such as offshore platforms, offshore wind farms). Taking offshore wind power as an example, monopile foundations are widely used abroad. During the operation of the wind turbine, with the superposition of the rotation of the blades and other marine environmental loads, the pile foundation will be subjected to vertical cyclic loads. Considering the 20-year operating life cycle, the pile foundation is subjected to a large magnitude of vertical cyclic load, which has a non-negligible impact on the vertical bearing capacity of the foundation structure. I...

AI Technical Summary

Problems solved by technology

When conducting model tests, expensive and complex vibration excitation equipment or conventional MTS hydraulic loading systems are usually used. The above-mentioned equipment has the following main defects:

[0003] 1. Equipment manufacturing, processing or leasing costs are relatively expensive, and more manpower and material resources are required for equipment maintenance;

[0004] 2. It is difficult to meet the waveform requirements of the indoor model test for the loading amplitude

For example, self-made vibration excitation equipment is difficult to ensure the stability and controllability of the loading waveform and realize the loading of complex load forms.

Conventional MTS usually has a large load magnitude, but the indoor model test requires a small load amplitude after similar reduction, so it is difficult to meet the test requirements by using MTS;

[0005] 3. There is a certain limit to the number of loading tests, and it is difficult to achieve a large-scale cyclic loading test

Self-made vibration excitation equipment is usually difficult to ensure the stability of the load waveform after a large number of loading times, while conventional MTS is difficult to achieve large-scale cyclic loading;

[0006] 4. Existing loading equipment is usually aimed at horizontal cyclic loading of pile foundations, and it is difficult to directly use them in vertical cyclic loading tests of pile foundations

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