In light of the problem that the rudaceous coal-bearing soil which ranges along with Guangzhou-Wuzhou Expressway can’t content for soil subgrade filler claim

two improvement schemes of the soil by respectively mixing quicklime and cement are put forward and improvement tests are accordingly taken for contrasting study according to the results of test in laboratory. The result indicated that the effect by mixing cement is evidently better than that by mixing quicklime of the rudaceous coal-bearing including consolidation properties

California bearing ratio (CBR)

water stability

etc.; its shear strength properties

unconfined compressive strength and resistance deformability are all evidently increased by mixing cement; in factors effecting strength of the rudaceous coal-bearing soil

cement mixing ratio is the most salient

followed by age and water content

and a fitted formula which is affected by multi-factors is put forward according to the test result of unconfined compressive strength. The rudaceous coal-soil which is mixed with about 3 percent cement is entirely able to meet the claim for subgrade filler

which offers useful reference to roadbed treatment in coal-bearing soil region.