The effect of particle gradation on the undrained monotonic and cyclic loading behaviour is presented. Straight line gradations of Earls Creek sand with varying coefficients of uniformity and identical mineralogy and D₅₀ were tested, using the triaxial test. Improved sample preparation techniques were used to ensure sample uniformity. The data indicates that, under monotonic loading, the relative shear-induced compressibilities due to a variation in the coefficient of uniformity are a function of the type of loading. Cyclic loading tests on isotropically consolidated samples showed that the effect of particle gradation depends on the relative density. At low relative densities, (less than about 45%), the well graded sand had greater cyclic strength than the uniform sand. At high relative densities, (greater than about 60%), this trend was reversed. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Present methods of determining design values for compression perpendicular to grain involves the testing of specimens of one specific geometry. The geometry of this test is very different from the geometries of bearing conditions occurring in practice. It was hypothesized that this test does not represent actual bearing conditions in practice and the object of this thesis was to find a more representative method of designing for compression perpendicular to grain. This thesis found the behaviour of wood in compression perpendicular to grain loading is strongly dependent on geometry in both the linear and nonlinear ranges of applied loading. A finite element analytical model, verified by testing, was used for the analysis. The analysis found the deflection is strongly dependent on the modulus of elasticity perpendicular to grain and nearly independent of other material properties. Also the capacity was found to be dependent on a characteristic material term and only weakly dependent on other material properties. A design method, one which includes an estimate of the deflection of the bearing plate, was developed from the results of this research. This proposed design method is valid for the capacities of the different geometries of bearing conditions occurring in practice. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate

Tests of Spatial Orientation (Card Rotations, Cube Comparisons) and Visualization (Form Board, Paper Folding, Surface Development) were administered to 537 (266 men, 268 women) university students. Participants rated the perceived difficulty of each of the tests on a 9 point scale ranging from 1 = very easy to 9 = very difficult. They were asked to indicate which of six problem solving strategies they used to solve the items on any particular test. The strategy statements were designed to tap part or whole problem solving strategies. Part strategies involved concentrating on salient aspects of a stimulus while whole strategies involved concentrating on an entire stimulus. Since men scored higher than women on all five tests analyses were performed separately for the sexes. For both men and women the first principal component accounted for more than 50% of the variance. Thus, previous findings of two spatial factors for men and one spatial factor for women were not supported. Problem solving strategy did not relate to performance on the spatial tests nor to difficulty ratings. There were no consistent sex differences in strategy except that women indicated that they guessed more on all tests. The limitations of introspective reports were discussed. For both men and women the perceived difficulty of a particular test correlated more highly with the total score on that test than with the total score on any other test. On the basis of this finding it was concluded that the difficulty index is a valuable one worthy of further study. The finding that men and women did not differ on mean difficulty rating on three of the tests, even though they differed significantly in performance on all tests, was interpreted to mean that each person subjectively rank orders the tests in terms of difficulty. It was hypothesized that the perceived difficulty of a test is, therefore, a function of the other tests included for study. There was moderate support for the hypothesis that, as the difference in rated difficulty for pairs of tests increases, the correlation between the two decreases. This was the case for six of 10 comparisons for men and three of 10 comparisons for women. It was suggested that this hypothesis would receive stronger support if tests of more distinct abilities were included in the same study. / Arts, Faculty of / Psychology, Department of / Graduate

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