This paper presents the difference between vacuum pressure and pore pressure reduction for vacuum preloading projects. The experimental results show that the pattern of the fluid flow under vacuum pressure can be classified into three categories—a single-phase water flow, an air–water two-phase flow, and a single-phase air flow. The field test results show that the vacuum pressure reaches the highest value at the ground level and the measured gradients of the vacuum pressure in the vertical direction are approximately 11 kPa/m. It is demonstrated that (i) the treatment area of vacuum preloading cannot be sealed and does not need to be airtight, (ii) the air–water mixture is drawn out from the treatment area under vacuum pressure and the groundwater level drops owing to the presence of air in practice, and (iii) there is an air–water two-phase flow in the unsaturated zone during preloading. The study shows that (i) the vacuum pressure is only a part of the pore pressure reduction along the depth of improving soil; and (ii) the vacuum pressure induces the soil to undergo isotropic consolidation, whereas the pore pressure reduction that is greater than the atmospheric pressure induces the soil to undergo one-dimensional consolidation.

Soil is the most common discontinuous granular material in the geotechnical engineering and its physical and mechanical properties have obvious grain size effect. In view of the insufficient of classical continuum mechanics and existing discrete mechanics, the matrix-reinforcing particles cell element model of soil introduces to account for the grain size effect and microstructure of the soil; then, based on the rotation gradient theory, the elastic-plastic stress-strain relations of soil with grain size factor obtains; finally, using the principle of virtual work establishes the corresponding finite element method.

A non-fired brick were manufactured by solidification of modified dredged soils. A novel solidified agent based on industrial wastes was prepared. A typical manufacture process of the non-fired brick comprised of mixing, stirring, tamping and maintaining. Several tests and measurements were conducted according to Chinese Professional Standard and National Standard. The results showed that the non-fired brick exhibited excellent performances and low toxicity. The non-fired brick was found to be a suitable material for use in the civil architecture.

The information extraction mode based on machining feature was presented for studying information extraction of part process model in the 3D CAPP system. The classification and its data structure of machining feature were investigated for defining the matching rule about the features. The feature authentication were availably fulfilled by converting the correlations of geometric topological into surface-edge adjacency graph for the part model, and the corresponding parameters extraction of feature were derived from traversing the feature tree of application development CATIA. The whole feature recognition process and parameter extraction process can become more directly and effectively by adopting the method of comparing machining feature with the predefined feature matching rules of the feature database.