Study On Application Of Impact Roller Compaction Technology To Ground Base And Subgrade In The Yellow River Alluvial Plain

It's lack of a good roadbed fill in the Yellow River Alluvial Plain,and the Yellow River Alluvial Plain soil is a unique soil which has special engineering properties. Impact roller compaction technology, as a new compaction technology, both have the characteristics of vibrating and ramming. Expressway construction in Shandong Province is rapidly developing.This situation provides impact roller compaction technology a broad space for development,and it will achieve great development.So,it is very important to study on impact roller compaction technology to ground base and subgrade in the Yellow River Alluvial Plain.The engineering properties of the Yellow River Alluvial Plain soil were analyzed through the test. Study finds that it has obvious layered structure and is made up with lots of low liquid limit silt,some low liquid limit clay mixed with part siltstratification and high liquid limit clay layer. It is mainly made up of silt,and the content is more than 90%. Generally,the content of clay is less than 10%,but it could be close to 20% in some area. It is epigranular and poorly graded, it has high porosiyt,low content of needle-like particles and high psephicity. Because soil particles are uniform hemispherical granule accumulation and the particle surface is crushing and spalling seriously,it's difficult to form effective embedded squeeze. This leads to difficult compaction and large settlement.Characteristics of impact rolling technology and causes of the compaction difficulties were analyzed. Impact roller compaction technology is suitable for compaction to ground base and subgrade in the Yellow River Alluvial Plain.Application of impact roller compaction technology to ground base in the Yellow River Alluvial Plain was researched. The relationship among degree of compaction, settlement,water content and compaction times was analyzed. The research suggests that compaction to ground base should use dual control with settlement and degree of compaction.It puts forward that the suitable impact rolling number of times is about 14.Control standards of ground base compaction is that degree of compaction between 0 cm and 20 cm should be not less than 90% and settlement should be not more than 10 cm. Because of high groundwater level,discontinuous construction can partly improve the compaction effect and prevent large-scale springing and frost boiling.Through the test,the paper studied the application of impact roller compaction technology to subgrade in the Yellow River Alluvial Plain.The relationship among degree of compaction,settlement,water content loose laying depth and compaction times was analyzed.It puts forward that the suitable loose laying depth should be 80 cm.And the relation formula between degree of compaction and compaction times is founded,which can guide the construction of subgrade compaction.