| 摘要 |
<p>A method of padding a trench includes the steps of automatically gathering at least a portion of excavated material from the berm of a trench, auomatically pulverizing at least part of the gathered material to form a pulverized material, and automatically conveying the pulverized material to the trench. The gathered material can be separated into at least two grades of material, only one of the grades of material being pulverized to form the pulverized material, another of the grades of material being returned to the berm. The pulverized material can be collected for use as a sandblasting sand.</p> |
