Expansive Soil Properties And Expansion Of Land Area Road Design

Research on the performance and design of expansive soils as road subgrade has great importance in solving pavement problems. Based on the theory analysis of the swelling and strength characteristics of expansive soils from China and abroad, this research performed laboratory tests of swelling, CBR and triaxial shear to investigate the influence of initial state parameters (water content, dry density and void ratio) of compacted expansive soil, and different testing conditions (i.e. applied surcharge loads or cell pressures) on swell percent, swelling pressure, CBR and shear strength. On the basis of investigation results, the state factor concept was developed. It was proved to have a significant linear relationship with swelling and strength characteristics. Based on this result, design chart suitable for design and evaluation of expansive soil as road subgrade as well as field compaction control was developed.