Subgrade Compaction Porosity Control Method

The intensity and stability of subbase relates to the certain filling of subbase's property and the degree of compaction in most degree.Silt and clay is the main fillings of high-qulity subbase in our country.As far as silt and clay is concerned, only controlling the dry density under compaction ,using actual compact-control method ,can not assure the intensity or stability of subbase absolutely. In addition to construction management, actual standard of compaction , detect and control method are also the main reasons of settlement and deformation of the subbase. Some typical soil in different types are researched in this article .The indoor tests which have been systemicly performed are as follows: Research the relationship between void ratio of clay subbase(high or low liquid limit) and silt subbase(low liquid limit),dry density and coordinate CBR value. Research the regularity of void ratio of clay subbase(high or low liquid limit) and silt subbase(low liquid limit) and dry density under the water influence. Research the relationship between void ratio ,inner friction angle and cohesion of low liquid limit silt subbase. Research the relationship between dry density,inner friction angle and cohesion of low liquid limit silt subbase. Research the rebound modulu of low liquid limit silt subbase under different control standards(void ratio and degree of compaction).Subsequently, relevant constructions have been built to vadilate the void control method, and the void ratio control method has been compared with the actual compaction method, reasonable compaction standard also has been established. Research and practice testifies that void ratio control method can be not only simply performed but also adapted to the diversification of soil and water content on the spot. So the void ratio method is feasible in compaction control of subbase.