Sand Bedding Course砂垫层
reinforced bedding course加筋垫层
thickness of bedding course垫层厚度
roughening with bedding course垫底加糙
antifreeze bedding course防冻垫层
bedding course groundsill垫层换填
sandy stone bedding course砂石垫层
bedding course with wind-blown sand风积沙垫层