1. Project background

Urban rail transit generally passes through the central area of the city. This area is usually an area where residential buildings and offices are concentrated, and its vibration impact cannot be ignored. The impact of vibration on the environment is multi-faceted, including the impact on the human body, the impact on work efficiency, the impact on surrounding buildings, and the impact on indoor high-precision instruments and equipment. With the large-scale construction and commissioning of subways, the vibration and noise generated during subway operation has also had a certain impact on people's lives. Among the commonly used vibration reduction measures in subways, rail fasteners are a common measure. With the efforts of scientific researchers, the medium vibration reduction fastener GJ-32 double-layer nonlinear vibration reduction fastener was developed. The vibration damping amount can reach 8-10dB.

2. Technological innovation points

Innovation points of vibration damping fasteners

(1) Nonlinear elastic pad

It adopts the unique technology of "nonlinear high torsional resistance vibration damping pad" design, which is not affected by the tightening force of the anchor bolt, makes full use of the elasticity of rubber, and has good vibration and noise reduction effects;

(2) Non-bonded and bolted detachable structure

The upper and lower iron plates of the fasteners are connected with a patented self-locking structure; longitudinal and lateral forces and turning moments can be transmitted without bolts; the elasticity of the middle rubber pad is fully utilized; assembly and disassembly are convenient;

(3) The pre-tightening force of the fastener system is adjustable

The pre-tightening force between the upper iron plate and the lower iron plate of the fastener can be adjusted on-site through the adjustment shim in the self-locking mechanism to meet the line installation adjustment and maintenance needs. The adjustable pre-tightening force self-locking mechanism meets the pre-pressure requirements of different rail fasteners in curves and transition sections.

(4) Effectively improve wave grinding

The natural frequency of the iron pad on the fastener and the connection rigidity of the fastener system are optimized, effectively suppressing the development of rail corrugation; at the same time, rail vibration and noise are reduced, and riding comfort is improved.

3. Practicality and application areas of the technology