From the fronds of Polystichum tripteron (KUNZE) P_R. a new norcarotenoid glycoside was isolated and shown to be (R, , R)--hydroxy-megastigma-4, -dien-3-one--O-β--glucoside. The fronds of Dennstaedtia wilfordii (MOORE) CHRIST. contain the same glucoside.

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One method currently being considered for the disposal of high level radio-active waste is burial in the seabed. When a hot object is buried in soil, the temperature of the soil adjacent to the object is raised and there is transient heat flow away from the object. The rise in the temperature of the soil causes excess pore pressures to be generated and transient pore water diffusion also takes place. A finite element formulation of the coupled heat flow and consolidation problem is presented. The computer implementation of this formulation is found to compare favourably with analytical solutions based on the same physical principles.

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A new analytical method is proposed for determining the inextensible grid reinforcement pullout resistance and pullout force/pullout displacement curve by using basic backfill soil and grid reinforcement properties. The pullout skin friction resistance/pullout displacement relationship is simulated by linear elastic-perfectly plastic model. A hyperbolic model has been proposed to represent the pullout bearing resistance/pullout displacement relationship in which the maximum bearing resistance of a single bearing member is determined using a new bearing capacity equation proposed in this paper. The influences of the grid bearing member spacing ratio, S/, the bearing member deflection rigidity, and the pullout softening behavior on the mobilization of pullout bearing resistance are explicitly included in the proposed model. Good agreement has been obtained between calculated values and laboratory test results.

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The small strain stiffness and anisotropic nature of two sands with different geological origin have been determined via laboratory seismic tests performed in a triaxial cell. Dry triaxial reconstituted specimens of Ticino river silica sand (TS) and of Kenya carbonatic sand (KS) were subjected to isotropic and anisotropic states of effective stress ; then both shear and constrained compression waves were propagated in vertical, horizontal and oblique directions by means of five couples of piezoelectric transducers especially arranged in the specimens. The propagated compression and shear waves allow the assessment of the constrained M₀ and shear G₀ moduli respectively, at very small strains where, as a first approximation many soils can be assumed, from an engineering point of view, to behave as an elastic cross-anisotropic medium with a vertical axis of symmetry. This paper, after a brief description of the novel measuring technique adopted and of the tested materials, summarises the test results and their interpretation in order to separate the effects of the fabric anisotropy from those produced by the state of effective stresses on soil stiffness. The stiffness and anisotropic response of the two tested sands are compared. Finally the results enable us to establish five independent constants of the cross-anisotropic elasticity model, which appears to be appropriate to reproduce the behaviour at small strain of the two sands.

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The main objective of this paper is to compare safety factors obtained from Morgenstern-Price, Janbu and Spencer methods with the factors calculated from the modified variational approach (Leshchinsky and Huang, 1992a). Such comparison is essential since there is no mathematical proof that the variational analysis indeed yields a minimum and thus, physically produce significant results. The safety factors compared well, indicating the variational analysis is on a par with acceptable existing rigorous methods. Availability of a user-friendly computer code may make the variational analysis useful to practicing engineers. However, its greatest potential at the moment is in 3- applications; i.., unlike other methods, its extension to 3- is straightforward.

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A procedure for limit equilibrium slope analysis based on a realistic consideration of the mobilized interslice shear forces is presented in this paper. This new approach ensures that solutions are kinematically admissible and the possibility of convergence problems, often associated with numerical solutions, is minimized. The proposed approach recognizes the importance of slip surface geometry in estimating interslice shear forces whether vertical or non-vertical slices are used in a limit equilibrium analysis. Illustrative examples are presented and the results shown to be reasonable. The calculated factors of safety based on the new method compare very well with values based on recognized methods of analysis. Yet the method is more direct and enables a proper visualization of the transfer of mobilized normal and shear forces through a sloping soil mass above a potential slip surface. The method also gives consistent results with non-vertical slices even if the shape of non-vertical slices is varied.

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Repetitive liquefactions in angular and subangular gravels from an alluvial fan, in the case of two earthquakes with accelerations lower than that of a former which had caused liquefaction some months before, are described. The liquefaction took place from the surface, down to a depth of approximately 10 m. Water laden with sediments spouted out for some tens of minutes after the strong motion ceased. Knowledge of the grain size distribution of the sediments inside the body of the alluvial fan roughly defines the areas of the fan prone to future liquefaction. Non-repetitive liquefaction in overconsolidated fine fluvio-lacustrine sand of glacial origin at the unusual depth of 14 m to 16 m is also described. From the observation of sand lifted up for 10 m inside a large diameter well, and of that which spouted out from several microvents, it was estimated that extra-pore pressure was close to lithostatic conditions. Nevertheless, modeling of intrinsic pore pressure buildup on the DESRA2 programme gives lower values than the experimental one. Geotechnical characteristics of the 12 m-thick sandy stratum indicate that the upper part is unusually soft, either due to water circulation or past repetitive liquefactions which prevented reconsolidation. It is suggested that excess pore pressure generated by the earthquake was also due to redistribution of pressure from adjacent sediments.

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As a fundamental study on dibenzothiepins, reaction of 11-phenyl-, 11-dihydrodibenzo [, ] thiepin-11-ol (10) or 11-chloro-11-phenyl-, 11-dihydrodibenzo [, ] thiepin (14) with triphenylmethyl cation or was examined under various conditions. 11-Phenyl-, 11-dihydrodibenzo [, ] thiepin-11-ylium salt (8) was isolated as a black powder (perchlorate) and a green powder (hexachloroantimonate), but BF₄ salt was obtained only as a solution. Treatment of the hexachloroantimonate with excess of was found to result in a novel dehydrocyclization reaction to give selectively , 13-dihydrofluoreno [1, a, -, ] [2]-benzothiepin-13-ylium hexachloroantimonate (19). Some discussions were made on the mechanism of the formation of 19.

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The objective of this paper is to develop a new vibro-compaction machine by investigating experimentally the effects of the frequency of an oscillator mounted on a tracked vehicle on the vibro-compaction of a high lifted decomposed granite sandy soil. By measuring the amount of depression of the ground surface, the dry density distribution in depth using a cone penetrometer, the normal earth pressure distribution in depth using a soil stress transducer, and the vertical and horizontal acceleration distribution in depth, the effects of the tracked vehicle on the increment of the soil compacting dry density in a deep stratum were considered theoretically for various kinds of frequency. It was observed that an oscillator frequency of 16 Hz with a constant amplitude of exciting force of .8 kN showed the maximum amount of depression of the ground surface and the maximum dry density distribution at deep stratum for the range of frequency from 16 Hz to 51 Hz. The ratio of dynamic shear stress to normal stress at 16 Hz proved to be large enough at deep stratum, so that an optimal alternative shear strain due to the impact force was developed on the whole range of the high lifted stratum. It was assumed that the increment in soil compacting density was the result of the effective dilatancy phenomenon.

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The present paper aims at developing a simplified model for a stress-strain relationship at small strains up to an initial yielding of homogeneous saturated frozen sand. The modelling of elastic moduli for an ice-sand mixture as a composite geomaterial is first introduced based on previous studies, where a saturated frozen sand is treated as the icesand mixture. The applicability of modelling the elastic moduli under constant temperature is then discussed from the theoretical and experimental points of view. In addition, the hyperbolic stress-strain modelling of saturated frozen sand at small strain is presented. The effect of the volume fraction of sand, stiffness of sand inclusion and temperature changes on the elastic moduli and the stress-strain behaviour up to about 1-2% axial strain, which is defined as an upper yield stress, are investigated through the model, whose applicability is verified in comparison with the experimental data.

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Stereoselective synthesis of , - and , Z-β-ionylideneacetaldehydes was accomplished from the β-ionone tricarbonyl iron complex, and the latter was converted to Z-retinoic acid.

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This paper presents the results of 24 centrifuge model tests of nailed soil slopes and vertical walls, constructed out of dry Leighton buzzard sand. The walls were initially supported by fluid pressure from flexible rubber bags against the face, and excavation was modelled by gradually draining the fluid from the bags. The finished model walls were 200 mm high and were initially tested at 30 g acceleration to correspond to a prototype structure .0 m high. If failure was not obtained, the acceleration was increased progressively to a maximum of g. No surcharges were applied. The main parameters varied in the tests were the wall slope, nail length, nail surface roughness, nail inclination, facing stiffness and facing roughness. Observations were made of the mechanism of failure when it occurred, of soil pressures on the facing, and of pre-failure deformations. Failure was always by pull-out rather than breakage of the nails, and a series of pull-out tests of the model nails was conducted to aid interpretation of the results. Failure surfaces were seen to have the shape of logarithmic spirals, and limit equilibrium analyses based on these surfaces agreed well with experimental observations. Prior to failure, earth pressures on the facing compared reasonably well with those calculated by Coulomb's method, except at the base of the wall. One test set out to model a full-scale trial wall, and although the construction process could not be exactly modelled in the small-scale centrifuge tests, comparisons were sufficiently good to give confidence in the model test results.

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This paper deals with the overall stability of an embankment foundation failure that lies at km 40+700 of the new Irbid-Amman Highway in Jordan. Slope stability back analysis was carried out for the slope to assess the conditions at time of failure, and estimate most representative shear strength parameters of foundation materials. Slope stability analysis was also carried out for proposed remedies. Probabilistic seismic hazard analysis was carried out for the landslide site. Peak Ground Acceleration (PGA) value of 0.2 g was estimated for design. This corresponds to a 90% probability of non-exceedence in a 50 year design life of the highway. Pseudo-static slope stability analysis was also carried out. The study concluded that the landslide movement occurred within the foundation colluvium material. It resulted primarily from the excessive load of the embankment and excess piezometric pressures generated within the slope. The most feasible remedial measure to stabilize the landslide area was removal of existing failed embankment down to the top of sandstone layer, and reconstruction (using imported free-drainage rockfill) of a split level embankment together with the construction of surface and subsurface drainage system. These measures were successfully implemented in the field.

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To remove some weak points of the limit equilibrium slope stability method, the authors have tried so far to develop a hybrid slope stability analysis method, in which stress and strain developed in a slope are determined by the finite element method, while the basic concept of the limit equilibrium method is adopted in the overall stability analysis. In this paper, first, the theory behind the hybrid slope stability analysis method is presented, together with the comparison of the proposed hybrid method and the conventional Bishop's method. Then, reinforcement mechanism and stability characteristics of the reinforced slope cutting are examined through numerical examples by the proposed method. Finally, practical application of the proposed method to an in-situ reinforcement slope stabilization project is presented. In consequence, the applicability and simplicity of the proposed method to the practical design works of reinforcement slope stabilization are demonstrated in success.

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Two new partially saturated tricyclic ring systems, , a, , 8, , 10, 10a, 11-octahydro-11-oxodibenz [, ] oxepins (3a and 3), and -thiepins (4a and 4) were synthesized. Compounds 4a and 4 were desulfurized to give a pair of isomeric 2-methylbenzoylcyclohexanes (10a and 10). Deuterated 4a and 4 (11a and 11) were prepared starting from butadiene- (12). The stereochemical features of 3a (trans), 3 (cis), 4a (trans) and 4 (cis) are compared with those of 10a, 10, 11a and 11 on the basis of proton nuclear magnetic resonance data.

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Piled bridge abutments on soft clay may be loaded laterally from horizontal soil movements generated by the approach embankment. A limited number of field trials have been described in the literature, although the data are generally limited in extent, complicated by variations in geometry or soil conditions, or of relatively poor quality. This paper presents the results of a series of centrifuge model tests aimed at clarifying the behaviour of piled bridge abutments on soft clay. The centrifuge modelling techniques and equipment used are initially described. Attention is focused on the induced pile bending moments and deflections, and the response is shown to be critically dependent on the factor of safety of the embankment against failure. The effects of variations in pile rake, embankment geometry and abutment wall loading are described. The response of pile groups with time after embankment construction is outlined and the causes of time dependent behaviour identified.

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