Road Spike Shaft Diameter and Tie Anchorage
- What are the common specifications of the shank diameter of spikes?
The diameter of ordinary wooden sleeper spikes is mostly 16mm and 18mm; the diameter of spiral spikes for concrete sleepers is commonly 22mm and 24mm; the diameter of special spikes for high-speed railways is mostly 24mm and 26mm; the diameter of spikes for special heavy-haul lines can reach 28mm to provide greater anchoring force. The design values of anchoring force for spikes of different diameters vary significantly. For every 2mm increase in diameter, the anchoring force can be increased by 15%-20%.
- What is the relationship between the shank diameter and the sleeper anchoring force?
Within a certain range, the larger the shank diameter, the larger the contact area with the anchoring agent or sleeper material, and the stronger the anchoring force. For example, the anchoring force of a 22mm diameter spiral spike is about 60kN, 24mm diameter can reach 75kN, and 26mm diameter can reach 90kN. However, if the diameter exceeds the design value of the sleeper nail hole by more than 3mm, it will cause the sleeper to crack, which will reduce the anchoring effect instead.
- What are the different requirements for the shank diameter of spikes for different types of sleepers?
Wooden sleepers are relatively soft, so the spike diameter should not be too large. 16-18mm can meet the anchoring needs, and too large a diameter is easy to split the wooden sleeper; ordinary concrete sleepers need 22-24mm diameter spikes to balance the anchoring force and sleeper strength; prestressed concrete sleepers have high strength and can use 24-26mm diameter spikes; heavy-haul railway sleepers need 26-28mm diameter spikes to resist greater lateral force.
- How to select the shank diameter of spikes according to the sleeper type?
Wooden sleeper track: select according to the density of wooden sleeper material, 18mm diameter for hard wooden sleepers, 16mm diameter for soft wooden sleepers; ordinary concrete sleepers: uniformly select 22mm diameter spiral spikes; high-speed railway ballastless track: match 24mm diameter special spikes; heavy-haul railway sleepers: select according to axle load, 26mm for 25t axle load, 28mm for 30t axle load.
- What problems will be caused by improper selection of shank diameter?
If the diameter is too small, the anchoring force is insufficient, and the spike is easy to loosen, leading to lateral displacement of the rail and excessive gauge deviation; if the diameter is too large, it will squeeze the sleeper nail hole, causing cracks in the sleeper, and in severe cases, the sleeper will fail. Both situations will increase track maintenance costs and even affect driving safety, so selection must be strictly in accordance with specifications.