Improved numerical modeling of rock masses through geostatistical characterization

Improved numerical modeling of rock masses through geostatistical characterization

52A The reference model is not directly applicable in situ. However, the model can applied in the field after a simple, but sometimes depth deper~ent...

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52A

The reference model is not directly applicable in situ. However, the model can applied in the field after a simple, but sometimes depth deper~ent, modification which requires a few measurements of N and Dr at the site. Auth.

82302~ ~ ~OAL MODELII~ OF ROCK MASSES THROUGH GEOSTATISTICAL CBARAcA~IZATION La Pointe, P R Proc 22rd US Symposium on Rock Mechar~cs, Cambridge, Mass, 29 J~ne-2 July 1981, P386-391. 1~bl Cambridge, Mass: MIT, 1981 A series ~f finite element simulations were carried out to model an ur~er~round cavern, as part of a site investigation ar~ design programme for cavern consi~.~ction of a supe~corductive magnetic energy stc~s~e unit. The simulations involved using c o n v e n t i o D a l techniques ~ a geoa~atistical techr~que, the T~rnlng Bands approach. The IX~pose was to improve n~merical modelling forecasts of cavern stability by examining and inec~Ix~atlng spatial correlation.

823029 UNFROZEN WATER CONTENTS OF SUBMARINE ~ O S T D R T E ~ W I ~ BY NUCLEAR MAGNETIC RESONANCE Tice, A R; A~erson, D M; Sterrett, K F Er4~mg Gecl, VI8, NI-4, Dec 1981, P135-146 ~Paper to 2r~ International Symposium on Grour~ Freezing, Tror~heim, 24-26 June 1980) Presents a method of using nuclear magnetic resor~nee (~MR) to measure unfrozen water content in frozen soils which also allows corrections to account for sample paramagnetic impurities. The total amount of u n f r o z e n water for each sample in the experiments is also determined by differential scanning calorlme%ry and these v a l u e s compared with the NMR results. Results agree well at low temperatures, and the paremagnetic effects are seen as not being very significant.

823026 TRIBOLOGY

AND THE CHARACTERISATION OF ROCK JOINTS Swan, G Proc 22~I US Symposium on Rock Mechanics, [email protected], Mass, 2 9 June-2 July 1981, I~2-~07. P~bl Cambridge, Mass: MIT, 1981

The p u r p o s e of t h e pape~ i s t o d e m o n s t r a t e t h e extent of the usefulness of tribolo~cal solut i o n s to rock Joint problems. Both profilc~etric

823030 NEW MES~OD FOR QUICK MEASURING AND COMPUPING PARAM~S OF ROCK JOINTING Thomas, A; Therme, P; Richard, P Proc 22r~ US Symposium on Rock Mechanics, Cambridge, Mass, 29 June-2 July 1981, ~08-413. Publ Cambridge, Mass: MIT, 1981

and material property data are examined. Tribological models fc~ both normal Bx~ s h e a r stress behavlc~r are then developed, with reference to experimental results. Experiments where Joints have bean deformed under normal load indicate a simple linear relationship between stiffness and stress. 823027 EXAMPLE OF FRACTURE C H A R A ~ I Z A T I O N IN GRANITIC ROCK Thorpe, R K Proc 22rod US Symposium on Rock Mechanics, Cambridge, Mass, 2 9 June-2 July 1981, I~67-~72. Publ Cambridge, Mass: MIT, 1981 A study of n~tural fracturing in granitic rock was comducted at the Stripa mine, Sweden, as part of thermomechanical experiments on %~lerg r o u ~ nuclear w a s t e stc~a~e. Two objectives were involved: (i) identification of maJc~ geologic features ( ~ i n g heater tests), eg faults, shear zones, dikes, which could then be described geometrically fcr input into n~e~ical models of the rock mass, and (2) provision of statistical i~formation on the Jointing (orientation, spacing, persistence) between ma~er features from which equivalent continuum properties could be estima~.

The method involves the measurement of fracture nets ar~ allows quick computation of the global density of fractures and the directional density curve of the fracture net.

Strength characteristics 823031 PROBABILISTIC MODELING OF UNCERTAINTIES IN SAMPLING AND TESTING FOR UNDRAINED Kureda, K; Chowdhury, R; Watar~be, K SOils FOUnd, V21, N2, Jure 1981, P~7-62 The reliability of geotechnical structures of short-term stability is isrgely affected by uncertainties in the measured ~r~Irained shear s t r e I ~ of soils, caused by: (i) inherent rar~om variation in soil properties in the in situ groutS, (2) stress release in boring, (3) mechanical disturbance during sampling ar~ specimen preparation, and (4) testing errers. These uncertainties are modelled in a probabilistic manner and a new probabilistic model for ~ a s u r e d nndrained strength is proposed for normally consolidated or [email protected] overconsolidated clay. It is concluded (based on comparison with actual data) that the model can well predict the parameters of in situ undrained strength based on measured undrained strength.

Texture, structure, composition and density ],23028 ESTIMATION

OF SPT-N AND RELATIVE DENSITY Fard~s, M N; Veneziano, D J Geotee_h Er~I~ Div ASCE, VI07, NGTIO, Oct 1981, P13~5-1359

A consistent set of models is developed for inference of the relative density (Dr) from the blowcount rA~mber of the SPT (N) under both laberatc~ and field corzlitions. The model in the laboratory (reference model) is based on a large data set, which consists of essentially all available laboratory information on Joint measurements of N, Dr and vertical effective stress. It takes explicitly into account errors in the laboratory determination of ~r and is of a form which makes its use particularly simple.

823032

SHEAR STRENGTH BEHAVIOUR OF OVERCONSOLIDATED CLAYS Krishna M~rT~hy, M; Sridharan, A; NagaraJ, T S Soils Found, V21, N2, June 1981, P73-83 Results from triaxial compression tests on 2 remoulded clays (a kaolinite and a silty clay), where both maximum past consolidation pressure a~d the overconsolidation ratio were varied, sre p r e s e n t e d . Test data w~re analysed in terms of Mohr-Coulomb ard Hvorslev failure envelopes. The results show that the effective stress MohrCoulomb failure envelopes are uniquely defined independent of overconsolidation ratio, past maximum pressure, and failure conditions such as