Nine representative groups of CBRtest of the high liquid limit soil improved by cement of 0%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0% along the Yunluo expressway of Guangdong province were conducted. The cement content at CBRvalue of 20 was determined, respectively, as the optimal cement content of high liquid limit soil classified by the different fine particles content, liquid limit, prime soil CBRvalues. The best cement content range was determined by considering integrally the three different elements, and useful conclusions were gained. The result showed that the effect of fine particles content on CBRvalue is greater than that of liquid limit. The optimal cement content of high liquid limit soil fluctuates in value of 2.0%. High liquid limit soil of lower liquid limit and smaller fine particles can be directly filled; high liquid limit soil of higher liquid limit and bigger fine particle content should be abandoned.
