The experiment focused on the absorption and drainage characteristics of recycled coarse aggregate. The recycled coarse aggregate bonded with strain gauges was embedded in C30 strength grade concrete, and the shrinkage strain of recycled coarse aggregate in concrete during drying shrinkage was measured directly. Based on the relationship between the strain and drainage rate of recycled coarse aggregate under different humidity conditions, the drainage characteristics of recycled coarse aggregate in concrete were calculated, and the relationship between the drainage rate of recycled coarse aggregate and the drainage rate of recycled coarse aggregate was established. The results showed that the trend line of strain and saturation curve of regenerated coarse aggregate was relatively close to that of natural coarse aggregate in the process of draining and drainage, and the strain variation caused by dry and wet of the two kinds of aggregate had a reversible trend. There was a linear relationship between the strain and the drainage rate of recycled coarse aggregate and natural aggregate. The shrinkage strain of coarse aggregate in concrete was smaller than that of specimen, and the shrinkage strains of recycled coarse aggregate and recycled concrete were larger than that of natural aggregate and concrete. The drainage rate of recycled concrete was higher than that of internal recycled coarse aggregate..
Infiltration and groundwater have been widely considered as the main factors that cause shallow landslides; however, the effect of runoff has received less attention. In this study, an in-house physical-process-based shallow landslide model is developed to demonstrate the influence of runoff. The model is controlled by coupling the shallow water equation (dynamic) and Richards’ equation. An infinite slope stability analysis is applied to evaluate the possibility of regional landslides. A real, small catchment topography is adopted as a demonstration example. The simulation illustrates the variations of runoff and the factor of safety (FS) during a storm. The results indicate that, after the surface becomes saturated, the FS may keep varying due to the increasing pressure head, which is caused by increasing surface water depth. This phenomenon most likely occurs downstream where the slopes easily accumulate water. The depth of the surface water may also be a factor of slope failure. Therefore, it is essential to increase the accuracy of calculating the runoff depth when assessing regional shallow landslides..
The erodibility parameters of barrier dam were an important basis for the evaluation of the outburst flood in the emergency treatment of the dammed lake. The erosion rate was typically modeled with excess shear stress model and Wilson model. However, there is no unified understanding of the range of erodibility parameters. In order to study the range of erodibility parameters of various types of soils and the relationship between the erodibility parameters of two models and soil properties, quickly determine the erodibility parameters of the dam, a database of 279 test results were collected from the literature review as well as by contacting researchers and organizations working on erosion around the world. The samples were classified into coarse-grained and fine-grained soils according to the unified soil classification system. Correlation analysis and regression analysis of the data were used to obtain the relationship between the erodibility parameters and soil properties. Four measures were used to evaluate the statistical significance of the relationship between erodibility parameters and soil parameters for coarse-grained and fine-grained soils: R2、MSE、Fvalue/Fstatistic and cross-validation. The erodibility parameters obtained from the experimental data were compared with the erodibility parameters predicted by the regression equation, the range of erodibility parameters of different soil and correlation between erosion parameters and soil parameters were obtained. According to the erodibility parameters database, the regression equation of erodibility parameters were obtained through statistical analysis of limited soil parameters and erodibility parameters to quickly predict the erosion rate of the soil. Finally, taking Baige weir plug as an example, according to the erodibility parameter database and statistical relationship established in this study, the erodibility parameters and erosion rate were analyzed rapidly. The research findings can be used to quickly determine the erosion parameters of the dam plug body, and provide help for rapid assessment of the risk of burst flood under emergency conditions..