How should the number of passes and time of Single Drum Vibratory Rollers be determined?

Factors:
1. Properties of the compacted material: including soil type (such as clay, sand, gravel, etc.), water content, particle size and grading, etc.
2. Compacting requirements: such as the specified compaction standard, flatness requirements, etc.
3. Layer thickness: The thickness of the compacted layer is different, and the required number of passes and time will also be different.
4. Performance of the roller: such as vibration frequency, amplitude, excitation force, etc.
Determination method:
1. Test section construction: Before the formal construction, a representative section of the road is selected as the test section. Rolling is carried out according to different rolling times (usually from less to more), and the compaction degree and other indicators are tested after rolling. According to the test results, the minimum number of rolling times required to achieve the specified compaction degree is determined.
2. Experience reference: Refer to the construction experience and relevant specifications and standards of similar projects, but still need to be adjusted according to the actual situation.
3. Real-time monitoring: During the rolling process, some detection equipment (such as nuclear density meter, sand filling method, etc.) can be used to monitor the changes in compaction in real time to determine whether the required compaction has been achieved and whether rolling needs to continue.