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Shear stress concentrations may promote damage and failure processes. Quantities of studies have focused on the direct shear loading test, while the analytical model has not yet been studied in depth. Aiming to fill the knowledge gap, the theoretical and numerical analyses of the shear stress distribution in the shear band were investigated. In order to reflect the variation in the stress state, the differential element method was first used. The shear stress distribution equation was derived from the stress equilibrium, geometric and physical equations. The shear stress distribution was plotted, using the proposed equation. After that, the ratio of yield strength to crack initiation strength was calculated. The analytical model was analyzed with FDEM simulation, and the results were compared with those obtained from the laboratory tests. Using the elastoplastic theory, the damage evolution and process in rock were characterized from laboratory scale. The implication for underground engineering analysis was finally discussed with a case study of strain rockburst in hard rock. The analytical model and results could provide a fundamental basis for stability analysis in geotechnical engineering.

In recent years, debris flow disasters have occurred frequently along the highway, causing river blockages and road interruptions, which seriously threaten the safety of people's lives and property. Highway G318 is an important throat project linking Sichuan and Tibet; at the same time, it is an important channel for the economic development of Sichuan and Tibet and the transportation of national defense materials. Taking the Linzhi–Lhasa Section of Highway G318 as an example, this study analyses the distribution law and characteristics of coupling factors of debris flows in the study area (under its topographical, hydrometeorological, geological, and structural conditions) using remote sensing interpretation, field surveys, and mathematical statistics. The research shows that: (1) The types and quantity of debris flows in the region show statistical laws under the factors of the slope, slope aspect, drainage area, and gradient of the gully. The vegetation coverage in the upper reaches of the Nyang River valley gradually decreases, and the average debris flow disaster density is 0.529/km, which is the most densely distributed area of debris flow. (2) The distribution density of regional debris flows in narrow valleys is greater than that in wide valleys, and those in the Nyang River basin are greater than those in the Lhasa River basin. (3) By comparing the tectonic geological map and the debris flow distribution map, it was found that the debris flow distribution is controlled by faults, and 71% of the debris flow basins have faults. (4) There is a significant positive correlation between the gradient of the material source area and the gradient of the debris flow gully, as well as a close positive correlation between the rainfall and the fault density, and a close negative correlation between the average gradient and the drainage area. Due to the unique topography and geomorphology of different regions, a difference in meteorology and hydrology occurred. This further affected the topography, geomorphology, and distribution of debris flow disasters. Based on the study of the distribution law of regional debris flow and geological environmental factors, this study provides strong support for regional debris flow prevention and related research.

Earthquakes produce some of the most violent loading situations that a structure can be subjected to and if a structure fails under these loads then inevitably human life is put at risk. One of the most common methods by which a structure fails under seismic loading is at the connection of structural elements. The research presented in this paper compares the performance of mathematical models of watertowers under seismic conditions. One type of model is assembled withconcrete panels that are connected by means of a novel interlocked mechanism. The performance of this modelwas tested against the performance of a conventional monolith watertower. Two variables were appliedsimultaneously when testing each model: earthquakes with different magnitudes and different mass of the elevated water tanks. The results of this experimental study demonstrated that across all tested seismic conditions, increasing the mass of the water tanks resulted in greater deformation of the watertowers. This was most pronounced for the monolith watertower model. With increasing mass of the water tanks across all seismic conditions, those watertowers composted of interlocked panels withstood increasing loading stresses more effectively than the monolith watertower.