We know that whether a vibratory roller or an impact roller is used, the speed of impact compaction will have a significant impact on the degree of compaction that can be achieved by the subgrade engineering soil or the ground raw material layer. The key to the speed of compaction lies in the use of compaction machinery and the basic characteristics of the compaction of the raw materials to be compacted, the compaction characteristics and actual effects of the road roller, the regulations on the construction quality of the project, the thickness and work efficiency of the laminate, and so on.
The speed of impact compaction is high, although the work efficiency is high, it often affects the actual effect of compaction to a certain extent under normal conditions; the speed of impact compaction is low, the compaction thickness can be increased, and the actual effect of compaction is improved, but the work efficiency is low, It will reduce the production efficiency and increase the construction cost. Therefore, according to the comprehensive factors such as compaction machinery, working conditions, engineering construction regulations, etc., choosing the appropriate compaction speed is a precious engineering construction experience.
The compacting speed of the vibratory roller is suitable for slow speed at the beginning. The compaction time period and vibration frequency of the raw material per unit surface area of the vibrating roller are higher than the compaction speed, and the actual effect will be more kinetic energy on the compacted raw material. After the compaction reaches the corresponding level, it is necessary to increase the speed to improve the compaction work efficiency, but the maximum speed is not suitable for exceeding 4km/h (about 66-67m/min), and the impact compaction speed is too fast, which will easily cause the compaction The flatness of the layers decreases.
The compaction speed of the impact roller is controlled within the range of 10~15km/h. This is mainly because the impact roller is driven by large amplitude and low frequency. Under the actual effect of the impact speed above 10km/h, the impact force is caused by the impact roller. The huge peak force pulse is equivalent to more than 5 times the line load of the tamping wheel of the vibratory roller, and the energy density is huge.
However, the compaction speed of the impact roller is not suitable for more than 15km/h. If the impact rolling speed is too fast, the kinetic energy of the actual effect will stay on the compacted raw material for a short time, which is similar to the fact that the feet of the scud do not touch the ground, which affects the shock wave. spread down.
Of course, the compaction speed is related to the operation and use of the driver, although it has a direct impact on the actual effect of compaction. However, the selection of different types and types of rollers also plays a crucial role in practical effects.
In order to improve the progress of the project and shorten the construction period, it is possible to appropriately increase the tonnage of the vibratory roller, or use the impact roller to replace the vibration roller for compaction. The impact roller can appropriately increase the thickness of the layer and improve the production efficiency of compaction.