Stability analysis of conical heaps

Stability analysis of conical heaps

246A 885356 Drainage spurs in cut slopes - a presentation of dimension design charts based on hydraulic and mechanical criteria. (In French) Aigle, P...

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246A

885356 Drainage spurs in cut slopes - a presentation of dimension design charts based on hydraulic and mechanical criteria. (In French) Aigle, P; Desnouvaux, F; Prost, J P Can Geotecb J V24, N4, Not, 1987, P590-600 Design charts have been developed to aid planning of parallel drainage spurs used with a drainage ditch on cut slopes. The method is based on theoretical and experimental research, and uses a composite analog model to simulate free-surface, threedimensional flow. The charts are of 2 types: (1) simple dimensioning charts which give quantitative information about possible combinations of depth and spacing for lowering water table and increasing safety factor; and (2) optimisation charts which estimate the depth of spur necessary to minimise the volume of draining material.

885357 Limit equilibrium method with local factors of safety for slope stability. Note Srbulov, M M Can Geotecb J V24, N4, Nov 1987. P652-656 Soil strength parameters or pore pressures often vary considerably within a slope, with consequences to slope stability calculations assuming homogeneity. A new limit equilibrium method suitable for heterogeneous slopes is proposed. A definition of local factors of safety distribution, along a tr_ial sliding surface and at the interfaces between wedge shaped slices, is introduced, which considers soil strain properties. The procedure is outlined and an illustrative example presented.

885358 Short-term slipping of a shallow excavation in gault clay Parry, R H G Inst Civ Engrs Proc V84, Ptl, April 1988, P337-353 Bank instabilities of a flood diversion channel were investigated in order to design remedial works. Site investigation of both slipped and stable sections was carried out. Slip zones in the overconsolidated clay were 20-100mm thick soft clay containing hard lumps. Back analysis using Bishop's method suggested slope angles were too steep. Precast concrete units were installed in the bottom of the ditch, with shallow slopes above.

885359 Design charts for vertical cuts. Technical note Leshchinsky, D; Mullett, T L J Geotech Engng Div ASCE Vl14, N3, March 1988, P337344 Design charts are developed which take into account the geometry (length/height) of the cut and the stand up time requirements (effective or total stress analysis). Results are presented in terms of safety factor and volume of potential sliding mass.

885360 Causes of two slope-failure types in continental-shelf sediment, northeastern Gulf of Alaska Schwab, W C; Lee, H J J Sea~ment Petrol V58. NI, Jan 1988, PI-II Slump and gravity flow have been identified on very shallow slopes (I.3 deg)in the Gulf of Alaska. Geotechnical investigations suggest that earthquake and storm loading plus cyclic degradation of sediment shear strength are responsible for the failures. The failure type is related to the loading. Long term

loading from storm waves is more likely to lead to cyclic degradation than the limited number of load cycles generated by earthquakes. Sediment gravity flow is generally induced by wave loading.

885361 Microcomputer-aided evaluation of earthquake-induced permanent slope displacements Houston, S L; Houston, W N; Padilla, J M Microcomput Civ Engng I/2, N3, Sept 1987, P207-222 The computer program DISPLMT has been developed to model permanent displacement of slopes due to earthquake action. It incorporates the Newmark procedure, modified to include a slip layer with softened properties at the location of the shear zone. Several options are available for describing the yield acceleration function. Slope movements can be displayed graphically. The use of the program to model displacements of an earth dam is illustrated.

885362 Steep slope stabilization for reclaimed terrain Elifrits, C D; Vories, K C; Haston, F F Min Engng V40. N3, March 1988, P196-199 The reclamation of land after surface mining can lead to oversteepened slopes which are subject to rapid erosion and gully development. The development of a designed drainage system of ditches and rip-rap protected waterways to stabilise the steep slopes by effective removal of runoff is described. Implementation of the design at Prairie Hill mine, Missouri, is presented, and shows that there was no erosion between the ditches or in the ditch channels, rip-rap scour was limited to the lower reaches of the channel, construction was easy and inexpensive, and that no remedial action or maintenance was required except at the steepened lower end of the waterway.

885363 Stability analysis of conical heaps Baker, R; Leshchinsky, D Soils Found V27. N4, Dec 1987. P99-110 A stability analysis based on variational formulation of the limit equilibrium slope stability problem is presented. The model uses general solutions to derive a complete solution for homogeneous conical heaps, assuming a one-sided failure. The results are presented in 2 stability charts. One allows estimation of the factor of safety for a given problem,whilst the second allows rational selection of the design safety factor where cost of potential repair is considered.

885364 Feasibility of highway crossing through landslide area on varved clays Nieuwenhuis, J D; van Genuchten, P M B Proc 5th International Congress International Association of Engineering Geology, Buenos Aires, 20-25 October 1986 V3, P1705-1712. Publ Rotterdam: A A Balkema, 1986 Pillars for an elevated highway were constructed across a landslide area in varved clays and moraines. Loads exerted on the pillars by the moving soils were less harmful than denudation of the land surface. The project was abandoned, but measurements of displacements were continued. Large soil blocks were seen to move quasi-individually along existing slip planes in periods when pore pressures were high after rain or snow melt. The causes of this stick-slip motion are discussed.

iS) 1988 Pergamon Press plc. Reproduction not permitted