As a new type of road equipment, the application range of highway guardrail pile drivers is very broad. It includes the treatment of shallow and weak foundations, layered reinforcement of high embankment subgrades, reinforcement of low embankment subgrades, and reinforcement of fills, as well as the borders of excavated roads. It's also used in the widening and reconstruction of old roads. During the use of highway guardrail pile drivers, the concept of compaction depth arises. So, how is this compaction depth defined?

Impact depth and effective impact depth are two concepts. The impact depth refers to the greater depth at which the average compaction degree of the soil can be increased by one percentage point. The effective impact depth is the thickness of the compacted layer that can meet the compaction design requirements.

The impact depth and effective impact depth depend on factors such as the model of the highway guardrail pile driver, the compaction medium, and the working speed. When the working speed of the highway guardrail pile driver is 12 km/h, the impact depth of collapsible loess is 3.89m-4.2m, and the effective impact depth is 2.2m-2.5m. Through the analysis of a large amount of test data, it is generally believed that the impact depth of highway guardrail pile drivers for different foundation materials is 4-5m, and the effective impact depth is 1.5-2.5m.

The main purposes of compaction by a highway guardrail pile driver are:

1. To eliminate the open spaces in the soil, reduce permeability, decrease the soil softening and expansion caused by water ingress, and maintain a stable state of the soil.

2. To maintain sufficient strength on the fill to support the loads occurring during transportation.

3. To greatly reduce settlements under pressure.

Highway guardrail pile drivers can also combine the compaction and settlement processes of concrete pavements. During rolling, the concrete layer and foundation are compacted and settled, with the pavement layer directly laid on top, which is faster than traditional rolling methods. The original concrete layer serves as the new subgrade, eliminating the original transportation process, which is both environmentally friendly and efficient.