Gravitational deformations of mountain ridges in the Rocky Mountain foothills

48A are found in soft claystone and mudstone strata which are susceptible to weathering. Most new slides are initiated by man's activities. 941377 Mud-flow in -Case Buonanotte' area, S. Stefano di Quisquina, Sicily Liguori, V; Pratini, P Proc 6th International Symposium on Landslides, Christchurch, 10-14 February 1992 VI, P153-158. Publ Rotterdam. A A Balkema, 1992 A landslide which threatens the Voltano Aqueduct in Sicily is examined. The mudflow originates from weathering of the Terravecchio clays and flows along a landslide channel. The geomorphological and geological profile is illustrated. Geometric, mechanic, and kinematic aspects of the slide are investigated. Selection and design of stabilising works, including reducing access of spring and meteoric waters, reprofiling, and revegetation, are discussed. 941378 Rainfall and soil slipping events in Vaiteilina Polioni, G; Ceriani, M; Lauzi, S; Padovan, N; Crosta, G Proc 6th International Symposium on Landslides, Christchurch, 10-14 February 1992 V1, P183-188. Publ Rotterdam: A A Balkema, 1992 Extreme rainfall in 1983 and 1987 triggered soil slips, debris flows, and debris avalanches into inhabited areas of Valtellina, northern Italy. The physical setting of the Alpine valley, details of the rainfall events, morphological parameters of the failed slopes, and soil mechanical properties are described and their relative importance to slope instability discussed. 941379 Investigation of the slide at the southern abutment hill of Viaduct No 1 Caracas-La Guaira highway, Venezuela Salcedo, D; Ortas, J Proc 6tb International Symposium on Landslides, Christchurch, 10-14 February 1992 V1, P189-198. Publ Rotterdam." A A Balkema, 1992 Reactivation of an ancient landslide is causing damage to the main highway connecting to Caracas. Development of the problem started in 1987. Aerial photographs from the period 1936-1981 have been studied to help delineate the slide extent. The surface geology is colluvial debris with limestone and schist bedrock. Boreholes have been sunk to depth 50m to locate the failure surface and topographical instruments installed and monitored. Tolerable and predicted movements of the structure are discussed. The slide is still moving but definitive solutions have not yet been developed. 941380 Sliding and multiple toppling failure in South Wales, UK Siddle, H J; Hutchinson, J N Proc 6th International Symposium on Landslides, Christchurch, 10-14 February 1992 V1, P213-218. Publ Rotterdam: A A Balkema, 1992 A recent, first-time landslide in a steep sandstone escarpment underlain by soft mudstones in the South Wales Coalfield is described. The failure started as a shallow slide immediately upslope and involved multiple toppling of joint-defined sheets in the sandstone plus sliding within the mudstone. Slope movement developed into a rotational slide with slip surface defined by bedding planes tilted downslope by toppling and by the underlying slide surface in the mudstone. Removal of material at the toe of the slope is the most likely cause of the failure.

941381 Gravitational deformations of mountain ridges in the Rocky Mountain foothills Stepanek, M Proc 6th International Symposium on Landslides, Christchurch, 10-14 February 1992 VI, P231-236. Publ Rotterdam: A A Balkema, 1992 Translational movements along moderately sloping bedding planes or other planes of weakness are observed in many rock masses. Such movements have resulted in the formation of deep troughs and subparallel fractures in the uppermost strata of the Trapper and Babcock Mountains in the Rocky Mountain Foothills. The friction angle of the sliding surface is greater than the slope of the discontinuity, which suggests the block movement is ancient. Stress relief during post-glacial excavation of adjacent valleys or frost action under periglacial conditions are possible mechanisms of the deformation. Stability of the rock masses is discussed. 941382 Assessment of slope stability by means of back analysis of measured displacements Sakurai, S Proc International Symposium on Assessment and Prevention o f Failure Phenomena in Rock Engineering, istanhui, 5-7 April 1993 P3-9. Publ Rotterdam." A A Balkema. 1993 A finite element back analysis procedure for cut slopes is presented. The rock mass is considered as a pseudo-continuum and described using an anisotropic material model, with smallest shear rigidity parallel to the sliding surface. Elastic, sliding, or toppling failure modes can be identified. Safety factor can be evaluated at each stage of the construction from back analysis of measured displacements. Several case studies are illustrated. 941383 What is coarse and durable mine waste rock? Vandre, B C Proc 29th Symposium on Engineering Geology and Geotechuical Engineering, Reno, 22-24 March 1993 P22-33. Publ Reno: University o f Nevada, 1993 Abandonment of overburden dump slopes at the angle of repose is commonly approved for metal mines, providing the slope material is coarse and durable. A draft specification for such armour material is presented and discussed. Amongst the topics considered are: required engineering judgement, now and in the future; coarseness sufficient to withstand design storm runoff; durability and its measurement; sampling and characterization; regulatory constraints; angle of repose vs regrading; and requirements for future work. 941384 Evaluation of failure potential in mudstone slopes using fuzzy sets Lee, D H; Juang, C H Proc Conference Stability and Performance o f Slopes and Embankments !!, Berkeley, 29 June-i July 1992 V2. PI1371151. Publ New York: ASCE. 1992 ( A S C E Special Geotechnical Publication No 31) A qualitative evaluation scheme for assessing slope failure potential is presented. Factors influencing stability have been identified and their relative importance determined on the basis of expert opinion and an evaluation-tree process. Soft data are translated into fuzzy numbers and handled using fuzzy set theory. A slope failure potential map for the southwestern Taiwan mudstone area is developed,