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Factual data for 70 rapid, giant landslides since 1900 show that the occurrence of these landslides was largely predisposed by tectonics, geological structures, lithology and topography, and often triggered by rainfall and earthquakes. In terms of mobile behavior, the giant landslides can be classified into three types: slides, slide-flows and flows. It is found that each type of landslide was constrained to certain geologic and topographic regimes. There are good correlations between kinematic parameters of landslides and slope geometries, which confirm the important role played by topographical condition in the mobile behavior of landslides. Moreover, it is also found that each type of landslide presents distinct geotechnical characteristics in terms of nature of the slip zone and properties of sliding mass. Brief analyses of five typical cases illustrate that landslide mechanisms can be conceptually depicted by failure mechanisms of their slip zones prior to onset of movement and following energy conversion during movement. Problems and questions related to experience in China suggest that comprehensive and systematic investigation and study on rapid giant landslides are urgently needed.

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The fluid-driven fracture initiation and propagation process in granular materials is inherently a coupled hydro-mechanical problem. The bonded-particle method was utilised to simulate the hydraulic fracturing process in granular materials, and different failure mechanisms were evaluated by analysing microcrack formation. Hydraulic conductivity was controlled by pore size and connectivity in the direction of flow, and a strain-dependent formulation was preferred to highlight the inherent link between hydraulic conductivity and pore size. The results show that for consolidated formations, fluid-driven fracture initiation and propagation are dominated by tensile failure, while for unconsolidated formations, shear failure seems to be more important than tensile failure during the hydraulic fracturing process. In general, the results of the fluid-driven fracture simulations are in accordance with the experimental data.

BackgroundIt is a challenge for orthopaedic surgeons to treat massive rotator cuff tears. The optimal management of massive rotator cuff tears remains controversial. Therefore, the goal of this study was to compare arthroscopic single- versus double-row rotator cuff repair with a larger sample size.Material/MethodsOf the subjects with massive rotator cuff tears, 146 were treated using single-row repair, and 102 were treated using double-row repair. Pre- and postoperative functional outcomes and radiographic images were collected. The clinical outcomes were evaluated for a minimum of 2 years.ResultsNo significant differences were shown between the groups in terms of functional outcomes. Regarding the integrity of the tendon, a lower rate of post-treatment retear was observed in patients who underwent double-row repair compared with single-row repair.ConclusionsThe results suggest that double-row repair is relatively superior in shoulder ROM and the strength of tendon compared with single-row repair. Future studies involving more patients in better-designed randomized controlled trials will be required.

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