when environment is deteriorating continuely

and the fitting soils soil for engineering are short and become more expensive. Technique for converting soft sludge to fitting engineering soil with content strength is very important and urgent. By mixing an extent lime to sludge dredged from riverway

and then

carrying on vacuum preloading added calcium lignosulfonate

serials of quality have been improved

including coefficient of permeability

unconfined compression strength and settlement deformation etc.

at one time

the relationships of dosages of calcium lignosulfonate and stable drainage-water volume and stable settlement and unconfined compression strength and void ratio would be studied and analyzed. The test results show that the strength is growing more quickly

hole volume of soil is being squeezed to a smaller

and subsequent settlement is becoming more little under lower water content situation after vacuum preloading. The soil will be consolidated to satisfy the standard qualification of fill. At last

through economical analysis

it is shown that this way could be accepted.