Two 14 WF 30 beams, each with an eight-inch diameter opening in the web, were tested. The beams were subjected to different loading conditions so that various combinations of shear and bending moment existed at the opening. A study of the stress distributions around the openings was made. The results were compared to the theories developed on the basis of the theory of elasticity and on the basis of the simplified method of the Vierendeel Truss solution. Expressions were derived for the stresses. The investigation showed the presence of high stress concentrations at the edge of the large circular opening and the reduction of the yield load capacity in every case examined. There was no reduction in the ultimate load capacity in the beams tested except in the case of pure bending.

The limitations of the presently available techniques concerning the prediction of frost effects were pointed out. A freezing apparatus was designed and constructed to conduct laboratory freezing tests on Arctic soils. The experimental observations did not agree with predictions based on the currently used grain-size criterion. A new frost-susceptibility concept was introduced end a method of evaluating relative frost-susceptibility was proposed. Predicted values were successfully compared with observed frost effects. The relative importance of external conditions was discussed for the particular case of rapid freezing. Laboratory observations were applied with success to the prediction of frost penetration for Lake Hazen conditions.

The investigations were carried out at the Primary Waste Water Treatment Plant in Beaconsfield, Quebec, and the plant performance and efficiency determined. The removal values of Suspended Solids and Chemical Oxygen Demand determined, compared favourably with expected. Values for primary treatment processes, found elsewhere. Results of experimental tests made at the plant showed that over 10% of solids in the primary sludge could be obtained by maintaining a sludge blanket depth in the thickener of over 3 feet. Thickening of sludge was controlled by using the concept of Sludge Volume Ratio S.V.R., defined as the volume of sludge blanket held in the thickener, divided by the volume of sludge pumped per day from the thickener.

The purpose of this study is to examine the treatment process at ten plants in the Montreal area, located on the Riviere des Mille Iles and the Riviere des Prairies, treating the water for public water supply. The efficiency and economy of these ten municipal filtration plants have been examined. Field surveys have been made and samples collected over a period of eleven weeks to accumulate data for interpretation. The quality of raw water and its fluctuation, particularly during the spring break-up of the rivers, is considered. The application efficiency and quantity of chemicals employed in water coagulation are investigated. The efficiency of water treatment prior to filtration is related to data of removals obtained.

This thesis deals with the computation and study of small elastic displacements and stresses in axially symmetric spherical shells. All loads and reactions are assumed to be symmetrical with respect to the axis of the shell and consequently the displacements and stresses are functions of only one independent variable, the co-latitude. Although the application of major interest to the author is the analysis of reinforced concrete shell roofs, the theory is equally applicable to the design of tanks and pressure vessels, radomes, nuclear reactor containment vessels and other structural components in the form of a spherical cap.

Strain rates ranging from 20% to 100% per second were used in consolidated-undrained triaxial tests, to investigate the influence of rate effects on the behaviour of cohesive soils. To apply the required loading rates, a hydraulic test unit was designed. Techniques were developed for producing saturated remoulded samples and for measuring the applied stresses, strain and pore pressures in the dynamic test. Electrical instrumentation was used for sensing and recording the transients. No pore pressure measurements were obtained in the dynamic tests conducted. For the same consolidation pressure, the strength of samples as determined in a triaxial test increased with increasing strain rates. Rate dependent dilatational effects are not the predominant cause of the observed behaviour.

The objective of this dissertation is the vibration and buckling control of piezo-laminated composite structures with surface bonded or embedded piezoelectric sensors and actuators by using the finite element analysis and LQR/LQG feedback control techniques. The focus is mainly on two aspects: the finite element part and the active control part. (1) The finite element part:Two finite element formulations for the piezo-laminated beams based on the classical Bernoulli-Euler and the Timoshenko beam theories are developed using the coupled linear piezoelectric constitutive equations, and the Hamilton variation principle. A C0 continuous, shear flexible, eight-node serendipity doubly curved shell element for the piezo-laminated composite plates and shells is also developed based on the layer-wise shear deformation theory, linear piezoelectric coupled constitutive relations, and Hamilton variation principle. The developed elements can handle the transverse shear strains, composite materials, and piezoelectric-mechanical coupling. Higher modes of vibration can then be predicted more precisely for thin to medium-thick multi-layered composite structures. They are evaluated both for the vibration and buckling of beam, plate, and shell structures. (2) The active control part: The suppression of vibration of a cantilever piezo-laminated beam and the control of the first two buckling modes of a simply supported piezo-laminated beam are studied first. Then, the vibration and buckling control of a cantileverpiezo-laminated composite plate are studied. Furthermore, the vibration control of a piezolaminated semicircular cylindrical shell is also studied. The results of the finite element analysis are used to design a linear quadratic regulator (LQR) controller and a linear quadratic Gaussian (LQG) compensator with a dynamic state observer to achieve all the controls. The control design begins with an approximate reduced modal model which can represent the system dynamics with the least system modes. A state space modal model of the smart structure which integrates the host structure with bonded piezoelectric sensors and actuators, is then used to design the control system. The designed LQR/LQG feedback controls are shown to be successful in suppressing the vibration and stabilizing the buckling modes of structures. Both the finite element analysis and the active control simulation results are consistent with the existing theoretical analysis results and the experimental data in the literature. Some important conclusions and interesting observations are obtained. / L'objectif de cette thése est le contrôle de la vibration et de flambage à l'aide de l'analyse par éléments finis et LQR/LQG technologies de contrôle de rétroaction pour les structures composites stratifiées piézo-électriques qui sont liés ou incorporés de surface de capteurs et d'actionneurs piézoélectriques. Il ya principalement deux parties ciblées. La partie des éléments finis : Deux formulations éléments finis pour les poutres laminées piézo-basé sur le classique d'Euler-Bernoulli et la théorie des poutres de Timoshenko, respectivement, linéaires couplées piézoélectriques équations constitutives, et le principe de variation de Hamilton sont développés. Un C0 continue, cisaillement flexible, à huit nuds élément de coque à double courbure sérendipité pour les plaques piézocomposites stratifiés et de coquillages est également dérivée basée sur la théorie de la couche-sage déformation de cisaillement, linéaires piézo-électriques couplés relations constitutives mécaniques, et le principe de variation de Hamilton. Toute la poutre, plaque, et des éléments de coque développés ont considéré la rigidité, de masse et les effets de couplage électromécanique du capteur piézo-électrique et les couches de l'actionneur. Les éléments de structure développéssont capables de traiter les effets non linéaires de déformation en cisaillementtransversal et la non-linéarité des matériaux composites, piézoélectrique-mécanique d'accouplement, et peut prévoir plus précisément les modes supérieurs de vibration, et peut être appliquée à partir de minces d'épaisseur moyenne structures composites multicouches. Ils sont évalués à la fois les vibrations et analyse de flambage de la poutre, plaque, et structures en coque. La partie de commande actif : La vibration de supprimer d'un porte à faux piézo-collé poutre, les deux premiers modes de flambement contrôle d'un appui simple piézo-collé poutre, et la vibration et le flambage contrôle de la charge d'un cantilever piézoélectrique stratifié plaque composite sont étudiés. Les résultats de l'analyse par éléments finis sont utilisés pour concevoir un régulateur linéaire quadratique (LQR) contrôleur et un linéaire quadratique gaussienne (LQG) compensateur avec un observateur d'état dynamique pour atteindre toutes les commandes. Les conceptions de commandes commencent par une méthode modale modle pour déterminer un modle modal réduit approximative qui peut représenter la dynamique du systme avec les modes les moins systme inclus. Un modle modal espace d'état de la structure intelligente qui a intégré la structure d'accueil d'colléscapteurs et d'actionneurs piézoélectriques, est ensuite utilisé pour concevoir le systme de contrôle. Les contrôles visant commentaires LQR/LQG sont avérés succs dans la suppression de la vibration et de stabiliser les modes de flambement des structures. Tant l'analyse par éléments finis et les résultats de simulation de contrôle actives sont compatibles avec les résultats existants d'analyse théoriques et les données expérimentales de la littérature. Quelques conclusions importantes et des observations intéressantes sont obtenues.

This thesis presents the account of an investigation into the effects of the rate of strain used in testing on the measured shear strength characteristics of three types of clay soils. The investigation consisted of undrained triaxial testing of specimens of each type of clay under varying conditions of cell pressure and strain rate. [...]

Mont St. Hilaire is situated about 25 miles south-east of Montreal. The top of this mountain consista of an outer rampart surrounding an inner basin. In the lowest part of the inner basin lies Lake Hertel, at approximately latitude 45 32' north and longitude 73 09 1 west. Mont St. Hil1aire and environs are shown on Map No. 1. The Lake is fed by two smal1 streams which drain the western and northern parts of the basin. The surface area of the Lake varies between about 71 and 75 acres, the average area being 72.73 acres at water surface elevation of 568 feet above mean sea level. The Lake and its drainage basin are shown on Map No. 2. Formerly, the Lake was drained by a stream at its south side; but in 1939, a dam was built across the south end to help regulate the Lake level. [...]

This paper describes an investigation into the efrect of "above ground" procedures and equipment involved in the making of the standard penetration test in soil. In the course of the experimental work an ana:qsis of the dynamics of the process was made. Certain conclusions as to the desirability of a truly standardized test were then deduced.