Types of Road Spikes and Anchorage Strength Control
- What are the common types of spikes? What scenarios are they suitable for?
Common types include ordinary spikes, also known as square - head spikes, with square shanks and large heads. They are mainly used in wooden sleeper tracks, fixing rails by the friction of being driven into wooden sleepers, suitable for lines with small and medium traffic volume. Spiral spikes with threads are connected to the sleeper's anchoring agent through threads, with strong anchoring force, suitable for concrete sleepers, and widely used in trunk railways and passenger dedicated lines. There are also buckle - type spikes, which are used with buckles, can better control the lateral displacement of rails, and are suitable for curve sections or lines with high requirements for track stability.
- What factors are related to the anchoring strength of spikes?
The strength of the spike's own material is the foundation. High material strength enables it to bear greater 拉力,and the anchoring strength is more guaranteed. The anchoring method has a significant impact. The anchoring strength of sulfur anchoring is affected by the proportion of sulfur mortar and construction quality, while resin anchoring is closely related to the performance and curing effect of resin anchoring agent. The material and state of the sleeper are also important. The strength and surface flatness of concrete sleepers will affect the anchoring effect of spikes, and the dryness and material density of wooden sleepers determine the anchoring force of ordinary spikes.
- What are the anchoring strength standards for spikes under different anchoring methods?
For spiral spikes with sulfur anchoring, the anchoring strength in concrete sleepers must not be less than 60kN to ensure that they do not loosen under train loads. Spiral spikes with resin anchoring have higher anchoring strength requirements, generally not less than 80kN, suitable for high - speed and heavy - haul railways. The anchoring force of ordinary spikes in wooden sleepers should not be less than 40kN to ensure effective fixing of rails.
- How to test the anchoring strength of spikes?
A pull - out test can be adopted. Use a special spike pull - out instrument, fix the pull - out hook on the spike head, slowly apply tension until the spike is pulled out or reaches the specified tension value, and record the maximum tension as the anchoring strength. During detection, random sampling should be carried out, with no less than 3 samples per kilometer of track, and it must be carried out 24 hours after the spike installation is completed to ensure that the anchoring agent is completely cured.
- What are the measures to improve the anchoring strength of spikes?
Select high - quality spikes and anchoring materials, such as high - strength alloy steel spikes and high - performance resin anchoring agents. Strictly control the quality of anchoring construction. For sulfur anchoring, ensure the accurate proportion of sulfur mortar and full pouring; for resin anchoring, ensure the uniform mixing and dense pouring of the anchoring agent. Pretreat the nail holes of sleepers, remove debris and water in the holes, and apply interface agent if necessary to enhance the bonding force between spikes and sleepers.