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Borehole shear test and slope stability
60A 882O58 Deformation response of seafloor sands to storm waves Siddharthan, R; Norris, G M Proc Sixtll (1987) International Mecham'cs and Arctic Eng-'meering Symposhun, Houston, 1-6 March 1987 V I, P417424. Publ New York: ASME, 1987 Response of seafloor soils to dynamic pressures caused by storm loading is important to the design of offshore structures. Deformation responses of a sandy, nonlinear, damped, porous seafloor to storm conditions have been analysed. The importance of inertia and damping effects and the influence of deposit depth and storm induced residual porewater pressures are analysed. Results indicated that response is basically governed by the thickness and the stiffness properties of the soil. Degradation of soil properties due to residual porewater pressure leads to increased transient displacements. 882059 Investigations of asymmetrical deformation behaviour at the horseshoe-shaped large cavern Mimaki, Y; Matsuo, K Proc International Symposium on Large Rock Caverns, Heisinki, 25-28 August, 1986 V2, P1337-1348. Publ Oxford." Pergamon Press. 1986 The powerhouse cavern for the lmaichi hydroelectric plant was excavated from rock of three types: breccia; silicious sandstone; and an alternation zone of sandstone and slate. Despite the design symmetry of the cavern, deformation behaviour was asymmetric. This could not be explained by back analysis. In situ stress relief tests confirmed that excessive deformation was taking place in the breccia, possibly due to the generation of microcracks on stress relief. Hydrostatic tests were carried out and demonstrated that microfractures were occurring at the boundary between the rock fragments and the matrix in the breccia. 882060 Damage mechanics approach to the analysis of an ur~ground opening excavated in a jointed rock mass Ohashi, T; Kusabuka, M; Kyoya, T; Kawamoto, T Proc International Symposium on Large Rock Caverns, Helsinki, 25-28 August, 1986 V2, P1349-1360, Publ Oxford: Pergamon Press, 1986 A new continuum model, the damage model (Kyoya et al, 1985), for jointed rock masses is introduced. Distributed discontinuities are assumed to be damage in such a way that they lower the value of the mechanical properties. Rock behaviour can be separated into two parts: (l) the effects of the constitutive model; and (2) the effects of the discontinuities. The excavation of a cavern in jointed rock is modelled using finite element analysis. Results using the damage model are compared with those from the conventional analysis using mechanical properties from in situ tests. Good agreement is achieved. The applicability of the damage model is discussed. 882061 Use of in situ tests for foundation design on clay Aas, G; Lacasse, S; Lunne, T; Hoeg, K In: Use of In Situ Tests in Geofedmieal Engbseering (papers to the Conference, Biueksbarg, 23-25 June 1986) P1-30, Publ New York: ASCE, 1986 (ASCE Geotechnical Special Publication No 6) Experiences in measuring undrained shear strength in clays are reported. An extension to the Bjerrum (1972) correlation curve for the vane shear test is presented. It is shown that the vane shear test interpreted with results from triaxial compression tests can predict in situ Ko. Correlations for the piezocone
test, a widely applicable and cost effective method to assess soil variability, are also presented. The importance of correlating cone factor to a well defined and relevant reference shear stress is emphasised. Other in situ tests, such as pressuremeter. dilatometer, hydraulic fracturing, and geophysical methods,do not rely on as extensive an evaluated data base as the first two methods and are subject to greater uncertainty. 882062 Borehole shear test and slope stability Handy, R L In: Use of In Situ Tests in Geoteclmical Engineering (papers t o the Conference, Blacksburg, 23-25 June 1986) P161-175. Publ New York: ASCE, 1986 (ASCE Geotechnical Special Publication No 6) Three Iowa landslides have been analysed on the basis of borehole shear test (BST) results. Soils included loess, glacial till, and clay shale. Back calculations consistently indicated zero cohesion in the shear zone after sliding, suggesting equilibrium deriving mainly from internal friction' Staged BSTs were also used to provide data for a probabilistic risk analysis of an unfailed slope of compacted soil over random fill. 882063 Assessment of rock strength by v w l inspection, ~ t load and uniaxial testing - a comparison using data from Chinnor Tunnel Rodrigues-Carvalho, J A Proc 5th International Congress International Association of Engineering Geology, Buenos Aires, 20-25 October, 1986 VI, P329-334. Publ Rotterdam: A A Balkema, 1986 Assessments of strength of chalk from the Chinnor tunnel, Portugal, were made by visual inspection, using a strength scale based on that recommended by the London Geological Society (1970), by point load tests, and by uniaxial compression tests. Visual inspection was unreliable and operator sensitive. Point load tests were simple, quick, require li[tle specimen preparation, yet gave results which correlated well with uniaxial compression tests, at about only one sixth o f the cost: Point load tests are suggested for systematic use when drill core logging. 882064 Scale effect during compressive strength testing of rocks Kaczynski, R R Proc 5th International Congress International Association of Engineering Geology, Buenos Aires, 20-25 OetOberi 1986 VI. P371-373. Publ Rotterdam: A A Balkema, 1986 Uniaxial compressive strengths were measured on cubic samples of edge 1.0,2.2, 3.2, 5.0 and 6.3cm of limestone, sandstone, granite, and basalt, Curves showing the decrease in uniaxial compressive strength with increase in sample volume are presented. 882065 Parametric back-analysis of shear strength of joints from rock slides Maugeri, M; Motta, E; Wang, S Proc 5th International Congress International Association o f Engineering Geology, Buenos Aires, 20-25 October, 1986 VI, P375-382. Publ Rotterdam: A A Balkema. 1986 Parametric back analysis is attempted for rock slides in jointed carbonate rocks which occurred during the Friuli earthquake of 1976. Results obtained show joint friction angles cOmparable with rock mechanics tests, which examine only a small area of sliding surface, but values of c~esion in natural failure are very low compared with those from laboratory tests.
~ 1988 Pergamon Press plc. Reproduction not permitted
test, a widely applicable and cost effective method to assess soil variability, are also presented. The importance of correlating cone factor to a well defined and relevant reference shear stress is emphasised. Other in situ tests, such as pressuremeter. dilatometer, hydraulic fracturing, and geophysical methods,do not rely on as extensive an evaluated data base as the first two methods and are subject to greater uncertainty. 882062 Borehole shear test and slope stability Handy, R L In: Use of In Situ Tests in Geoteclmical Engineering (papers t o the Conference, Blacksburg, 23-25 June 1986) P161-175. Publ New York: ASCE, 1986 (ASCE Geotechnical Special Publication No 6) Three Iowa landslides have been analysed on the basis of borehole shear test (BST) results. Soils included loess, glacial till, and clay shale. Back calculations consistently indicated zero cohesion in the shear zone after sliding, suggesting equilibrium deriving mainly from internal friction' Staged BSTs were also used to provide data for a probabilistic risk analysis of an unfailed slope of compacted soil over random fill. 882063 Assessment of rock strength by v w l inspection, ~ t load and uniaxial testing - a comparison using data from Chinnor Tunnel Rodrigues-Carvalho, J A Proc 5th International Congress International Association of Engineering Geology, Buenos Aires, 20-25 October, 1986 VI, P329-334. Publ Rotterdam: A A Balkema, 1986 Assessments of strength of chalk from the Chinnor tunnel, Portugal, were made by visual inspection, using a strength scale based on that recommended by the London Geological Society (1970), by point load tests, and by uniaxial compression tests. Visual inspection was unreliable and operator sensitive. Point load tests were simple, quick, require li[tle specimen preparation, yet gave results which correlated well with uniaxial compression tests, at about only one sixth o f the cost: Point load tests are suggested for systematic use when drill core logging. 882064 Scale effect during compressive strength testing of rocks Kaczynski, R R Proc 5th International Congress International Association of Engineering Geology, Buenos Aires, 20-25 OetOberi 1986 VI. P371-373. Publ Rotterdam: A A Balkema, 1986 Uniaxial compressive strengths were measured on cubic samples of edge 1.0,2.2, 3.2, 5.0 and 6.3cm of limestone, sandstone, granite, and basalt, Curves showing the decrease in uniaxial compressive strength with increase in sample volume are presented. 882065 Parametric back-analysis of shear strength of joints from rock slides Maugeri, M; Motta, E; Wang, S Proc 5th International Congress International Association o f Engineering Geology, Buenos Aires, 20-25 October, 1986 VI, P375-382. Publ Rotterdam: A A Balkema. 1986 Parametric back analysis is attempted for rock slides in jointed carbonate rocks which occurred during the Friuli earthquake of 1976. Results obtained show joint friction angles cOmparable with rock mechanics tests, which examine only a small area of sliding surface, but values of c~esion in natural failure are very low compared with those from laboratory tests.
~ 1988 Pergamon Press plc. Reproduction not permitted