Anchoring Methods and Load-Carrying Capacity of Rail Spikes
- What are the common anchoring methods for spikes? What are their characteristics?
Common anchoring methods include sulfur anchoring. Sulfur, cement, sand, etc. are mixed in proportion, heated and injected into the nail hole, and the spike is fixed after curing. It has high anchoring strength and simple construction, but high - temperature operation has certain dangers and is not conducive to environmental protection. Resin anchoring uses resin anchoring agent to cure and anchor the spike through chemical reaction. It has high strength and environmental protection construction, is suitable for various sleepers, but the cost is relatively high. There is also mechanical anchoring, which fixes the spike through expansion bolts or press - in structures. It is easy to install, can be disassembled and reused, has relatively low bearing capacity, and is suitable for temporary tracks.
- Which spike anchoring method should be selected for different sleeper types?
Wooden sleepers usually adopt mechanical anchoring or sulfur anchoring. Mechanical anchoring is convenient for installation and disassembly, and sulfur anchoring can provide high anchoring force. Concrete sleepers mostly use resin anchoring because of its high anchoring strength and no damage to concrete sleepers, which can adapt to the characteristics of concrete sleepers. Reinforced concrete sleepers can also use sulfur anchoring, but attention should be paid to controlling the anchoring temperature to avoid sleeper cracking.
- What is the testing method for the anchoring bearing capacity of spikes?
A pull - out test can be carried out. A pull - out instrument is used to apply tension to the spike, and the maximum tensile force when the spike is pulled out is measured, which is the anchoring bearing capacity. Generally, the anchoring force of spikes on concrete sleepers is required to be no less than 60kN, and that on wooden sleepers no less than 40kN. The lateral force test can also be used to measure the ability of the spike to resist lateral force and evaluate its stability under the lateral load of the train.
- What impact do environmental factors have on the anchoring bearing capacity of spikes?
Humid environment will reduce the strength of sulfur anchoring,
because sulfur is easy to absorb moisture and deteriorate, leading to a decrease in anchoring force. High - temperature environment may deteriorate the performance of resin anchoring agent and affect the anchoring effect. In high - temperature areas, high - temperature resistant resin anchoring agent should be selected. Acidic soil environment will corrode spikes and anchoring materials, reducing the anchoring bearing capacity. It is necessary to use anti - corrosion treated spikes and acid - resistant anchoring materials.
- How to improve the anchoring bearing capacity of spikes?
Select appropriate anchoring methods and high - quality anchoring materials, such as resin anchoring for lines with high bearing requirements. Increase the anchoring depth of the spike. On the premise of not affecting the sleeper structure, appropriately increasing the anchoring depth can improve the anchoring force. Ensure the cleanliness and dimensional accuracy of the nail hole to avoid debris affecting the combination of anchoring materials with sleepers and spikes. Carry out surface treatment on the spike, such as galvanizing, to enhance its adhesion with anchoring materials.