- Email: [email protected]
Evaluation of the design strength value for stiff clays
148A 933O70 High temperature properties of roof rock of coal Hettema, M H H; De Pater, C J, Wolf, K H A A Proc I S R M Symposium: Eurock'92, Chester, 14-17 September 1992 P93-98. Publ London." Thomas Telford, 1992 High temperature stability of the underground cavity is essential for in situ coal gasification to be successful. To assess roof properties under in situ conditions, triaxial tests were carried out at temperatures up to 800 deg C and confining pressures up to 14.2MPa on 80ram by 40ram cylindrical samples of roof rock taken from the Beringen mine, Belgium. The different thermal and mechanical properties of the laminated carbonaceous shale and laminated shaly siltstone components are described and their implications for cavity stability discussed. 933071 Effects of joints on the strength and deformability of rock masses Kulatilake, P H S W; Wang, S; Ucpirti, H; Stephansson, O Proc I S R M Symposimn: Enrnek'92, Chester, 14-17 September 1992 P105-110. Publ London." Thomas Telford, 1992 A method is proposed to allow study of the effect of nonpersistent joint parameters on the geomechanical properties of a rock mass. Nonpersistent actual joints are combined with generated fictitious joints to divide the rock mass into polygons (2D) or polyhedra (3D). The fictitious joint parameters are selected such that these joints behave as intact rock. The properties of the jointed rock mass can be analysed using the distinct element method. Preliminary indications are that it is possible to obtain REVs and REV properties of rock masses with respect to both deformability and strength parameters.
933074 Evaluation of the design strength value for stiff clays Al-Yousif, M M; Traczyk, R Proc Ninth Asian Regional Conference on Soil Meckanics and Foundation Engineering, Bangkok, 9-13 December 1991 V I, P7-10. Publ Thailand." Southeast Asian Geotechnical Society, 1991 The presence of fissures or slickensides in stiff clays creates severe problems when sampling for testing to obtain design strength values. The variability of measured strengths possible is illustrated for samples from Mosul (Iraq) and Turow (Poland). Errors that may arise through inadequate statistical interpretation of triaxial test results are described. Various methods of evaluating design strength values are compared, and that used by the Polish mining industry, unconfined uniaxial tests on undisturbed samples, is considered to give reliable results. 933075 Tensile strength tests on ¢ohuive COml~e~ soils Favaretti, M Proc Ninth Asian Regimmi C o n f r e r e on Soil M e c h a ~ s and Foundation E ~ 4 ~ c r i q , l~mgkok, 9-13 December 1991 V1, P37-40. Publ Thailand." Southeast Asian Geotechnical Society, 1991 Tensile strength of soils is low compared to compressive strength and in engineering applications is often considered as small or zero. To examine some factors affecting tensile strength, spfit-tensile and double-punch tests were carried out on 3 artificial soils (kaolin, kaolin-20% bentonite, kaolin-20% sand) prepared by mixing according to Standard AASHTO procedures. Correlations between tensile strength, unconfined compressive strength, water content, and plasticity index of the compacted samples are evaluated.
933072
Modified Imrelmle jack Li Guangyu; Zhoubohai; Zhu Zuoduo Proc 3rd lwtermWio~ Sympodnm on Field Meoa~rcments in Geomccha~s, Oslo, 9-11 September 1991 111, P33.42. Publ Rotterdam: A A Balkema, 1991 Different values of Young's modulus of rock masses will be obtained according to the measurement technique employed. Borehole methods have advantages in flexibility of location and orientation of measurement, and of these the borehole jack is applicable to the stronger rocks. The original Goodman jack is illustrated and its main disadvantages summarised. Problems of platen/borehole wall mismatch and platen bending have been solved in a modified instrument, the BJ-110. The new jack has higher resolution and accuracy. Calibration tests show that no further correction is necessary for the measured deformability. 933073 Some applications of fuzzy mathematics to reek engineering and slope stability Xiao, B; Carter, J P; Yu, X Proc 6tliAustroiia-New Zeaitmd Comferemce on Geomeeha~s, Cheistclmrc& 3-7 FebrNry 1992 P474-479. Publ New Zealand: New Zealand Geomechanies Society, 1992 The basic concepts of fuzzy mathematics are introduced: fuzzy sets, fuzzy numbers, and inference. Determination of fuzzy values of important rock mass parameters is described. Two illustrative examples of the use of fuzzy mathematics are presented. In the first, a method to determine the cohesive strength of a rock mass is shown. The second concerns evaluation of the stability factor of a rock slope.
933076 Pint-cyclic monoto~ ~ l ~ m ~ m r of a marine city Jitno, H; Vaid, Y P Proc Ninth A s i a Rqkmai ConStance om Soil M c e k a ~ s and Fon~latlon E q 4 ~ l q , ~kok, 9.13 Dwar-mker 1991 VI, P41-44. Publ Thailand: Southeast Asian Geotechnical Society, 1991 Design of foundations on clay soils must take into account possible effects of cyclic loading. The influence of cyclic loading on post-cyclic undrained stress strain behaviour of an undisturbed marine clay (Cloverdale Clay) has been examined. The loss of undrained strength and stiffness observed is not uniquely related to amplitude of cyclic strain, nor can it be explained in terms of pore pressures generated during cyclic loading. A rational explanation in terms of hysteretic work absorbed by the clay during cyclic loading is proposed. 933077 Verification of CBR and elastic modules values derived from local DCP tests Livneh, M Proc Nimk Asian RegioMl Coafmme~ o~ Soil M t c k a ~ s awl Foudatio~ ~ , Baggkok, 9-13 Decemb~ 1991 VI, P45-50. Publ Thailand: Southeast Asian Geotechnical Society, 1991 The dynamic cone penetrometer (DCP) test is becoming increasingly used for assessing in situ elastic modulus of pavements as it is quick, simple,cheap, and does not require excavation of the existing pavement, as for the CBR test. The DCP-CBR relation currently used in Israel has been re-validated with further data to improve confidence in the DCP.
© 1993 Pergamon Press Ltd. Reproduction not permitted
933074 Evaluation of the design strength value for stiff clays Al-Yousif, M M; Traczyk, R Proc Ninth Asian Regional Conference on Soil Meckanics and Foundation Engineering, Bangkok, 9-13 December 1991 V I, P7-10. Publ Thailand." Southeast Asian Geotechnical Society, 1991 The presence of fissures or slickensides in stiff clays creates severe problems when sampling for testing to obtain design strength values. The variability of measured strengths possible is illustrated for samples from Mosul (Iraq) and Turow (Poland). Errors that may arise through inadequate statistical interpretation of triaxial test results are described. Various methods of evaluating design strength values are compared, and that used by the Polish mining industry, unconfined uniaxial tests on undisturbed samples, is considered to give reliable results. 933075 Tensile strength tests on ¢ohuive COml~e~ soils Favaretti, M Proc Ninth Asian Regimmi C o n f r e r e on Soil M e c h a ~ s and Foundation E ~ 4 ~ c r i q , l~mgkok, 9-13 December 1991 V1, P37-40. Publ Thailand." Southeast Asian Geotechnical Society, 1991 Tensile strength of soils is low compared to compressive strength and in engineering applications is often considered as small or zero. To examine some factors affecting tensile strength, spfit-tensile and double-punch tests were carried out on 3 artificial soils (kaolin, kaolin-20% bentonite, kaolin-20% sand) prepared by mixing according to Standard AASHTO procedures. Correlations between tensile strength, unconfined compressive strength, water content, and plasticity index of the compacted samples are evaluated.
933072
Modified Imrelmle jack Li Guangyu; Zhoubohai; Zhu Zuoduo Proc 3rd lwtermWio~ Sympodnm on Field Meoa~rcments in Geomccha~s, Oslo, 9-11 September 1991 111, P33.42. Publ Rotterdam: A A Balkema, 1991 Different values of Young's modulus of rock masses will be obtained according to the measurement technique employed. Borehole methods have advantages in flexibility of location and orientation of measurement, and of these the borehole jack is applicable to the stronger rocks. The original Goodman jack is illustrated and its main disadvantages summarised. Problems of platen/borehole wall mismatch and platen bending have been solved in a modified instrument, the BJ-110. The new jack has higher resolution and accuracy. Calibration tests show that no further correction is necessary for the measured deformability. 933073 Some applications of fuzzy mathematics to reek engineering and slope stability Xiao, B; Carter, J P; Yu, X Proc 6tliAustroiia-New Zeaitmd Comferemce on Geomeeha~s, Cheistclmrc& 3-7 FebrNry 1992 P474-479. Publ New Zealand: New Zealand Geomechanies Society, 1992 The basic concepts of fuzzy mathematics are introduced: fuzzy sets, fuzzy numbers, and inference. Determination of fuzzy values of important rock mass parameters is described. Two illustrative examples of the use of fuzzy mathematics are presented. In the first, a method to determine the cohesive strength of a rock mass is shown. The second concerns evaluation of the stability factor of a rock slope.
933076 Pint-cyclic monoto~ ~ l ~ m ~ m r of a marine city Jitno, H; Vaid, Y P Proc Ninth A s i a Rqkmai ConStance om Soil M c e k a ~ s and Fon~latlon E q 4 ~ l q , ~kok, 9.13 Dwar-mker 1991 VI, P41-44. Publ Thailand: Southeast Asian Geotechnical Society, 1991 Design of foundations on clay soils must take into account possible effects of cyclic loading. The influence of cyclic loading on post-cyclic undrained stress strain behaviour of an undisturbed marine clay (Cloverdale Clay) has been examined. The loss of undrained strength and stiffness observed is not uniquely related to amplitude of cyclic strain, nor can it be explained in terms of pore pressures generated during cyclic loading. A rational explanation in terms of hysteretic work absorbed by the clay during cyclic loading is proposed. 933077 Verification of CBR and elastic modules values derived from local DCP tests Livneh, M Proc Nimk Asian RegioMl Coafmme~ o~ Soil M t c k a ~ s awl Foudatio~ ~ , Baggkok, 9-13 Decemb~ 1991 VI, P45-50. Publ Thailand: Southeast Asian Geotechnical Society, 1991 The dynamic cone penetrometer (DCP) test is becoming increasingly used for assessing in situ elastic modulus of pavements as it is quick, simple,cheap, and does not require excavation of the existing pavement, as for the CBR test. The DCP-CBR relation currently used in Israel has been re-validated with further data to improve confidence in the DCP.
© 1993 Pergamon Press Ltd. Reproduction not permitted