Abstract:Recent

Publication information Landslides, 3 (1): 51-61Publisher Springer were used to model the slide and it was found that the features observed on site could easily be reproduced. These included confirmation that thin layers of peat could be stable on steep slopes but the margin of safety reduces rapidly under elevated pore pressure conditions. As was observed in the field, the analyses suggested the most vulnerable zone was the upper layer of weathered rock but that slides could occur in the peat if its thickness was appreciable. Careful site characterization is vital in such studies. Here efforts have been made to understand the effect of fibres on the peat strength and some sensitivity analyes have been performed to assess the critical engineering parameters of the peat.

No abstract

Publication information Landslides, 8 (3): 391-401Publisher Springer incidence of such events but they seem to occur in clusters with intervening quiet periods.These clusters coincide with periods of intense rainfall. For many slides at least two causal factors can be identified. Primarily these comprised intense rainfall but human activities such as road construction and peat cutting also contributed to the slides.Detailed geotechnical testing of the peat, including laboratory direct simple shear tests (DSS), is reported for two of the slides. Backanalysis of these two failures suggest that the mobilised strength of the material in the failure surface is similar to that measured in the DSS tests. However conventional geotechnical analyses need to be treated with caution as they fail to account for the complex interactions in the sliding surface and in particular the lubricating role of water.

This paper presents and analyses the findings of a landslide inventory survey undertaken in deeply dissected upland valleys in layered Carboniferous lithology, Rhondda Valleys, South Wales. This area has one of the highest recorded concentrations of landslides in the UK.The paper analyses the terrain factors identified at landslide sites (lithology, slope angle, geographical setting) with factors denning the landslide (such as type/depth of movement, age, activity, material, areal extent, geometry). Using these data, a composite profile of probable landslide sites is developed. This provides a valuable tool in further quantifying likely landslide hazard at sites, giving an indication of the potential of, for example, first-time failures or whether degraded relict landslides may be present.Discussion is provided on the findings, particularly landslide locations within the valley and their age and current state of activity.