A set of systematic experimental methods, including 3D accuracy scanning and identification of discontinuous surface topography, physical model construction, and laboratory direct shear experiment under different directions and normal stresses, was proposed to research the influence of discontinuity roughness on strength and deformation of discontinuity. During physical model construction of discontinuity, three types of discontinuity and rough natural rock joint surface models were constructed and moulded. Meanwhile, many influence factors of discontinuity surface topography, such as asperity inclination angle (AIA), asperity height (AH), normal stress (NS), and shear direction (SD), were considered during the direct shear experiment. On the basis of the experimental results, it can be found that there were two types of failure modes under different loading conditions, which were named “failure by shearing through the asperities” and “failure by sliding over the asperities”. The obvious stress concentration phenomenon, climbing, and cutting effects appeared in the process of the direct shear experiment. In addition, the accurate identification of surface topography of natural rough rock joint surface was carried out using three-dimensional sensing system (3DSS) and self-programming software before and after the experiment. The subsamples with the same surface topography as the original samples were moulded using a self-developed instrument. Then, the mechanical behavior of the original samples and subsamples for the natural rough rock joint surface under different shear directions and normal stresses was studied. The results show that the shear displacement under different shear directions and normal stresses is very large before it reaches the failure state. And the residual strength of the original samples is higher than that of the subsamples. In addition, failure modes of the subsamples are main failure by shearing through the asperities due to the significant difference between peak shear strength and residual strength. The failure modes for parts of the original samples are failure by sliding over the asperities. The change ratio of area for the discontinuity after the experiment depends on surface topography, strength of heave on the surface of discontinuity, and particle size of minerals on the surface of discontinuity.

The dynamic compaction method is effective to reinforce soft soil foundation with a low degree of saturation. However, deep soft soil foundation with high degree of saturation has some different characteristics. It has been widely considered that dynamic compaction method is unsuitable to improve the characters of deep soft soil foundation with high degree of saturation. In this article, we will show that the dynamic compaction method with vacuum well-point dewatering is effective to deep soft soil foundation with high degree of saturation reinforcement. In situ and laboratorial experiments are used to assess the reinforcement effect of the deep soft soil foundation with high degree of saturation. Our results show that the dynamic compaction method causes long dissipation time of pore water pressure, and the dynamic compaction method with vacuum well-point dewatering makes construction time of a project 25% shorter. The effective depth of deep soft soil foundation with high degree of saturation reinforcement using the two experimental methods can reach to 8.0 m. In comparison with the total settlement and layered settlement of the dynamic compaction method with vacuum well-point dewatering, the dynamic compaction method settlement is relatively smaller. For soils with depth of 4 m, the reinforcement effect of dynamic compaction method with vacuum well-point dewatering is obviously superior to dynamic compaction method. Based on these results, we suggest construction procedures for different reinforcement depth of soils and construction time.

It is essential to determine rockmass mechanical parameters in stability assessment. The structural z is the main factor in this regard, and we know little about the relationship between mechanical parameters and multiple structure planes. In this paper, we have conducted a series of numerical tests to obtain mechanical parameters for a dam foundation in Southwest China. The biaxial numerical test was performed based on the discrete element method. This numerical test considers the spacing, types, dip angles, and size effect. We established a relationship of mechanical parameters between small size lab samples and large size field samples. We forecasted the strength parameters for a spillway slope in Southwest China. The dip angle has a significant effect on the slope strength and stability. In this case, the rockmass fracture stress-dip angle curve forms a U-shaped distribution. The X-shaped double structure plane demonstrates severe strength weakening relative to a single structure plane. As structure plane spacing reaches a certain level, its influence on rockmass strength diminishes. The elementary volume of the rockmass for dam foundation analysis is about 4 m × 4 m × 4 m.

Numerical simulation technology not only could effectively predict the defects on the forming product, such as wrinkle , rupturing, but also could display the stress, strain distribution and forming pressure. The numerical simulation was completed by DYNAFORM solfware, and the result of numerical was using to conduct the double-wall air compressor forming parts forming process inspection and forming mold design optimization.