However, the traditional method will be applied merely after the hard shell appears ,which will last almost a whole year leaving the soil in the sun .

The paper is based on a series of research on physical and mechanical properties of hard shell pumice aggregate and a new type lightweight hollow concrete block.

The foam glass with crust layer on the surface of the foam layer had been studied.

The paper relates to study on a foam glass and a crust layer which covers surface of thefoam layer, The foam glass having crust layer improved in machanical capability.

Numerical analysis of vertical additional stress spreading on soft clay foundation with dry crust;

Calculation of proportional limit load for soft clay foundation involving the effect of dry crust;

Study of characters and formation mechanism of hard crust on tidal flat of Yellow River estuary;

The presence of hard crust lying on soft soil foundation changes the mechanics characteristic of soft soil foundation.

Combined with the observation results from the experimental engineering of the Hefei - Xuzhou Expressway, an appraisal was made of the property of the hard crust under the road dyke.

Using traditional calculating ways,it is impossible to obtain precise result of stress distribution and deform of hard shell dam.

Meanwhile, the effect of hard shell course on the settlement and lateral displacement of the soft ground and the reflection on the soil pres- sure are analyzed.

The hard shell course on soft clay foundation has such characters as stress distribution,back berm,lagging behind of settlement and closed action.