Enhancement of slope stability by vegetation

247A 866256 Peat slides in Teesdale and ~Veardale, Northern Pennines, July 1983: description and failure mechanisms Carling, P A Earth Surf Land Process Vll. N2. March-April I986. P193206 Five slides, which occurred after intense rainfall, have been investigated. Stability analysis was carried out, treating the peat slides as shallow translational slips. The probable important roles played by open moor drains, natural soil pipes and prior cracking of the peat in the rapid transfer of the water to the failure zone within an impervious sensitive clay beneath the peat are demonstrated. It is suggested that there may be a gradation of failure type for peat slopes, from the classic bogburst to slips involving rigid peat blocks. 866257 Influence of weathering on the geotechnical properties and slope angles of mudstone in the Mineoka earth-slide area, Japan Matsukura, Y: Mizuno, K Earth Surf Land Process VII. N3. May-June 1986. P263-273 Three active earth slide slopes have been studied. Slope angles ,xerc measured, the residual shear strength of the soil was determined and the degree ol" weathering of the soil examined by mineralogical study and X-ray diffraction to identify the cla.v mineral content. It is sccn that as the degree of weathering increases, residual shear strength and slope angle both decrease. 866258 Form and stability of a double undercliff: an example from south-west England Pitts, J Engng Geol l'22. N3. ..Ipril 19,~6. P209-216 Details are presented of a double undercliff, an unusual landform feature on the coast of southeast Devon. The double undercliff is the result of two separate landslides on argillaceous formations within the 127m high cliffs. The stability' of the slopes in each case depended on the shear strength of bedding laminations, and hence upon ,,'cry low or zero cohesion. The future stability of the undercliffs is dependent mainly upon t, ndrained crown loading, for the upper undercliff from the degradation of the backscar, and for the lo~er undercliff from the landslide above. 866259 Enhancement of slope stability by vegetation Barker, D H Ground Engng VI9. N3. April 1986. PII-15 The work of several field and laboratory rcscarchcrs sho~s that the depth,strength and concentration of roots of grasses, shrubs and trees arc such that they can contribute directly to the stability of slopes ',~ith respect to shallow translational failures. A root reinforcement model is presented which assumes that the failure mode is tensile failure of the roof fbres. The analytical process involved in quantifying the effect of plant roots in stabilising a slope is illustrated by a case where a shallow soil layer supports vegetation on a infinite slope. It is concluded that through the increased use of specially selected varieties of plants, it is possible for engineers to harness, on a sound analytical basis, economical and effective means of enhancing the stability of slopes with respect to shallov,' translational failures.

866260 Generalized probabilistic approach for slope analysis: practical application to an open pit iron ore mine Young. D S Int J Min Geol Engng V4. NI. March I986. P3-I3 An example of the generalized probabilistic approach to slope anal.~sis is given through a case study on an iron ore mine. A step by step engineering procedure is described, so that a practical application can be made under different field conditions. Auth. 866261 Regional method to assess offshore slope stability Lee. H J; Edwards, B D J Geotech Engng Div ASCE V112, N5, May 19,~¢6. P489-509 A method using laboratory-determined properties of short gravity-core samples to quantify regional variations of the factors relating to slope stability is presented. The method is most applicable to offshore environments of gentle relief and simple subsurface structure and is not considered a substitute for subsequent site-specific analysis. Four sites off California and Alaska contain acoustically defined sediment failures. Calculated critical earthquakes factors in thcsc failed areas arc typically lower than in adjacent unfailcd areas, a rcsuh lending credence to the method. 41 rcfs. 866262 Soil arching in sandy slopes Bosschcr. P J: Gray, D H J Geotech Engng Div ASCE VII2, N6. June 19~'6. P626-645 This study exarnines the role of soil arching in discrete pile retaining walls and provides an information base for rational design. Comparison of the experimental and theoretical results indicates that discrete piles, embedded in a slope into a firm, non-yielding base, can provide significant additional stability to a slope if conditions for soil arching arc met. Piles can be installed v,ithout signiticantly decreasing slope stability' during construction. For retaining wails that rotate vertically about the base between 'fixed" side supports, the data obtained by the modified Bransby and Smith nurncrical method closely approximate experimental results. A loose deposit does not preclude the possibility of mobilizing soil arching or side friction. In soldier pile and logging systems, material costs, strengths, and sizes can be optimized to achiexe maximum bencft from soil arching. 866263 Soil pipes and slope stability in Hong Kong. Technical note Brand. E W: Dale, M J; Nash, J M Q J Engng GeM V19. N3. 1986, P301-303 Attention is now being focused on pipes in Hong Kong as a major contributory factor to frequent landsliding. A brief summary of work in this field is noted. 866264 Variable interslice force inclination in slope stability analysis. Technical note Chugh, A K Soils Found V26. NI. March 1986. P115-121 The use of variable interslice force inclination for slope stability analysis of earth deposits by the Spencer procedure, based on the limit equilibrium method, is described. Its computer implementation gives results essentially identical to those of the Morgcnstern-Price method. Necessary checks on the solution to ensure compliance to theoretical assumptions made in the analysis are discussed. A sample problem of an embankment dam is examined.

1986 Pergamon Journals Ltd. Reproduction not permitted