Due to their unique properties, fiber reinforced plastics (FRPs) can provide a possible alternative to steel because of their high strength-to-weight ratio and excellent resistance to electrochemical corrosion. Accelerated exposure tests to simulated field conditions were conducted on eleven different commercially available FRP rebars and tendons. In addition, long-term relaxation losses and fatigue characteristics of two carbon and one aramid FRP tendons were also examined. Test results showed durability problems associated with E-glass and AR-glass FRP rebars, and excellent durability exhibited by the carbon and aramid based tendons. Relaxation losses were higher in solutions than in air and they were limited to 12% for carbon and 18% for aramid tendons. Excellent fatigue characteristics were exhibited by carbon and aramid tendons up to stresses corresponding to 60% of their ultimate strength and stress range up to 10% of ultimate strength.

One laboratory technique to determine the unit side resistance of piles is the rod shear test. In a rod shear test a model pile is placed inside a cylindrical soil specimen. A confining pressure is then placed around the specimen/pile assembly and the model pile axially loaded. In some cases rod shear tests in sands have produced anomalously high interface friction angles (δ) which may be, at least in part, due to differences in how the normal stress on the model pile has been interpreted. Therefore, the usefulness of the rod shear test as a means to determine interface behavior for pile design is questionable. In this study, a new rod shear device was constructed to determine the behavior of steel-sand interfaces, and a numerical model was used to further evaluate the results. The interfaces tested were smooth and rough model piles in dense and loose sand. Results for the smooth pile tests are consistent with published values. However, tests with the dense and loose sands using rough piles produced interface friction values that were, in some instances, higher than the dilatant friction angle (φ(d)) for the sand at comparable stress levels. Elastic and elasto-plastic (modified Cam-clay) models failed to predict the high interface friction angles. Therefore it is suggested that the rod shear test imposes heretofore unrecognized kinematic restraints to volume change that, coupled with the discrete nature of the sand, lead to the development of a complex arching system The result is that effective normal stress on the pile is increased beyond the applied confining pressure. Evidence for such behavior included the observation of secondary features in the dense sand following pile displacement, the existence of force chains and work with discrete element systems showing that stress distribution in dense arrays is nonuniform.

This report describes the experimental and analytical results for the development of a methodology for predicting the stress-strain response of simulated concrete (mortar) in infrastructure. Lamb wave analysis is used to predict material properties of mortar specimens, which are used in the initial research as a substitute for concrete. The mortar specimens are tested to measure their stress-strain response under uni-axial compression. The results of the nondestructive and mechanical stress-strain testing are correlated to develop the model based on the Disturbed State Concept (DSC), a unified approach for modeling material behavior. This information can be used to design rehabilitation strategies, and can also lead to the development of new computer based equipment that can be used in the field for defining the remaining life. At this time, the research involved one-dimensional testing. The proposed methodology can, however, be extended and improved by conducting two- and three-dimensional testing of concrete specimens, along with laboratory and field validations.

Interaction between the superstructure and foundation depends on the behavior of soil supporting the foundation. To study the behavior of interfaces, it is necessary to characterize the behavior at the interface, model constitutive relationships mathematically, and incorporate the model together with the governing equations of mechanics into numerical procedures such as the finite element method. Such an approach then can be used for solving complex problems that involve dynamic loading, nonlinear material behavior, and the presence of water, leading to saturated interfaces. In this dissertation, a general model, called the Disturbed State Concept constitutive model has been developed to model saturated Ottawa sand-Concrete interface and saturated Nevada sand. In the DSC, the material is assumed to transform continuously from the relative intact state to the fully adjusted state under loading. Hence the observed response of the material is expressed in terms of response of relatively intact and fully adjusted states. The DSC model is a unified approach and allows for elastic and plastic strains, damage, and softening and stiffening. The model parameters for saturated Ottawa sand-Concrete interface and saturated Nevada sand are evaluated using data from laboratory tests and are used for the verification of DSC model. The model predictions showed satisfactory correlation with the test results. In this dissertation, a new program based on concept of neural computing is developed to facilitate determination of interface parameters when no test data is available. The back propagation training algorithm with bias nodes is used to train the network. The program is developed in FORTRAN language using Microsoft Developer Studio. The reason for selecting FORTRAN as a programming language to develop Biased Artificial Neural Network (BANN) simulator is due to its proficiency in number crunching operations which is the core requirement of the ANN. A nonlinear dynamic finite element program (DSC-DYN2D) based on the DSC model is used to solve two problems, a centrifuge test and an axially loaded pile involving interface behavior. Overall, it can be stated that the DSC model allows realistic simulation of complex dynamic soil-structure interaction problems, and is capable of characterizing behavior of saturated interfaces involving liquefaction under dynamic and earthquake loading.

In 1940 R. A. Moyer and D. S. Berry established ball-banking limiting values (and side friction factors) for use in determining the maximum recommended speed of horizontal curves on roads (the value shown on advisory speed plates). This speed is also referred to as the "advisory speed", "safe speed", or the "comfortable speed" of the curve. This speed is distinguished from the "critical curve speed", the speed value at which loss of control is imminent. Literature review showed some concern for the criteria for the installation of curve warning signs but no recent concern for the goodness of the limiting values. Ritchie et. al. has provided updated research on lateral acceleration values. Their research, plus results of this study, show that the 1940 values are outdated. This work concludes with recommended modern ball-banking limiting values, side friction factors, and lateral acceleration values. Recommendations regarding further research are stated.

The reversed cyclic loading responses of reinforced concrete walls coupled with steel beams are investigated. Four full-scale segments of coupled walls having both "shear critical" and "flexure critical" steel coupling beams with their ends embedded in the walls were tested. The reversed cyclic loading responses of these specimens are compared with those of conventionally reinforced and diagonally reinforced concrete coupling beams. Design and detailing guidelines are proposed for both the steel coupling beams and the reinforced concrete embedment regions. Non-linear dynamic analyses of prototype coupled wall structures, comparing conventional and diagonal reinforcement details with the proposed flexure and shear critical steel coupling beams are presented. / Four full-scale reversed cyclic loading tests of shear deficient reinforced concrete coupling beams were conducted to study efficient ways of retrofitting these beams. An unretrofitted control specimen and three specimens with different retrofit details were tested. The retrofit procedure investigated involved applying steel plates to one side of the coupling beams to determine ways of increasing the shear strength of the beams such that the nominal flexural capacity may be attained. Different methods of attaching the retrofit plates using structural epoxy and mechanical anchor bolts are investigated. A method for determining the influence of the steel plate retrofit on the shear capacity of the beam is developed. Non-linear dynamic analyses comparing the structural responses of unretrofitted and retrofitted prototype structures are also presented.

Wood Poles are extensively used in North America as supports for electric distribution lines. On average, wood poles have a service life of 40 years with a replacement cost of approximately $2000. Since the distribution network is of relatively recent construction, maintenance and replacement costs have been relatively small compared to the total number of poles in service. / The goal of this thesis is to use the FORM/SORM algorithm to evaluate the reliability of a single pole and the results obtained when applied to a sample of 887 wood poles inspected in the field. The procedure was also applied to a sample of poles designed according to the current codes in order to calibrate the evaluation procedure. The results indicate that the proposed procedure will improve the current maintenance and replacement strategy by guarantying a more uniform level of reliability throughout the network and by decreasing by up to 33% the number of wood pole replacements. (Abstract shortened by UMI.)

Fiber Reinforced polymer composite materials offer great potential for waterfront structural applications due to their excellent corrosion resistance, and high strength to weight ratio. / The purpose of this thesis is to develop a deflection based design approach for composite sheet pile wall, based on the traditional free-earth support method, but modified to allow the use of deflection criterion. With a simplified earth pressure loading on the wall, the relationship between maximum bending moment and maximum bending deflection and the relationship between maximum shear force and maximum shear deflection were established. 16 case studies were carried out to include walls ranging from 1.5m to 4.5 m tall and water level to wall height ratio from 0.1 to 0.4. Two deflection limits, L/60 and L/100 were employed in developing the design charts. / To implement the deflection based design, the proper characterization of flexural rigidity (EI) and shear rigidity (KAG) of the sheet pile panels was vital. Tests were conducted on the connected panels to obtain the rigidities. (Abstract shortened by UMI.)

Batch soil washing experiments were used to evaluate the feasibility of using biosurfactants for the removal of heavy metals from a contaminated soil and sediments. Surfactin from Bacillus subtilis, rhamnolipids from Pseudomonas aeruginosa and sophorolipid from Torulopsis bombicola were evaluated using a soil contaminated with hydrocarbon and metals (890 mg/kg zinc, 420 mg/kg copper, 12.6% oil and grease) and metal contaminated sediments (110 mg/kg copper, 3300 mg/kg zinc). / Although water alone removed insignificant levels of metals, results showed that the biosurfactants could remove 5% of the zinc (with 12% rhamnolipid) and 19.5% of the zinc (with 4% sophorolipid with 0.7% HCl). Copper could also be removed and was most efficiently extracted (greater than 25%) with 12% rhamnolipid or with 2% rhamnolipid with 1% NaOH. 1% NaOH alone removed only 5% of the copper and 2% zinc. After a series of five batch washes, 90% of the copper could be removed by 0.1% surfactin with 1% NaOH while 4% sophorolipid with 0.7% HCl was able to remove 100% of the zinc. From the sediment, a single washing with 0.5% rhamnolipid removed 65% of the copper and 18% of the zinc whereas 4% sophorolipid removed 25% of the copper and 60% of the zinc. / Sequential extraction procedures were used on the soil and sediments. For both matrices, the carbonate and the oxide fractions accounted for over 90% of the zinc present in the soil. The organic fraction constituted over 70% of the copper in the soil and sediments. Sequential extraction of the soil and sediments after washing with the various surfactants indicated that the biosurfactants, rhamnolipid or surfactin with NaOH, could remove the organically-bound copper and that the sophorolipid with acid could remove the carbonate and oxide bound zinc and cadmium. / Concerning the mechanism for metal removal by the surfactants, the techniques of octanol-water partitioning, ultrafiltration and zeta potential measurements indicated that the surfactants removed the metals first by sorption at the soil interphase, followed by desorption of the metal through interfacial tension lowering and fluid forces and then solubilization of the metal within the micelle.

In the absence of specific guidelines for the seismic analysis of self-supporting telecommunication towers, designers may be tempted to apply simplified building code approaches to these structures. However, these towers respond to earthquakes in a different fashion than that of shear buildings. The objective of this research is to propose simplified methods for the seismic analysis of self-supporting telecommunication towers. / The author studied the specific problem of self-supporting lattice telecommunication towers using numerical simulations and applying the modal superposition method and the response spectrum technique on ten existing towers, typical of microwave towers usually erected in Canada. The analyses are carried out using a set of 45 strong motion horizontal accelerograms to study the horizontal effects. Vertical dynamic effects are studied using two approaches: the first considering the same horizontal accelerograms in the vertical direction after reducing their amplitudes to 75%, the second using a distinct set of 55 vertical accelerograms. / As a first stage, simple regression analyses are performed on the results to yield earthquake amplification factors for the base shear and the total vertical reaction. These factors are presented as functions of the tower's largest flexural period or largest axial period of vibration as appropriate and peak ground acceleration at tower site. They can be used by designers to estimate the expected level of dynamic forces in self-supporting telecommunication towers due to an earthquake. / As a second stage, a simplified static method is proposed to estimate the member forces in self-supporting telecommunication lattice towers due to both horizontal and vertical earthquake excitations. It is assumed that the lowest three flexural modes of vibration are sufficient to estimate the structure's response to horizontal excitation accurately, while only the first axial mode will reflect the actual behavior of towers in response to vertical excitation. An acceleration profile along the height of the tower is defined using the spectral acceleration values corresponding to the lowest three flexural mode shapes or the lowest axial mode as appropriate. The mass of the tower is calculated and then lumped at the leg joints. A set of equivalent static lateral or vertical loads can be determined by simply multiplying the mass by the acceleration. The tower is then analyzed statically under the effect of these forces to evaluate the member forces. The maximum error associated with the proposed simplified static method is found to be 25% in the extreme cases with an average error of +/-7%. / The effect of including antennae clusters is also addressed in the analysis and findings are summarized in the thesis. / The study is extended to include transmission line towers in order to simplify the response of coupled tower-cable system by replacing the cables with an equivalent mass. Several frequency analyses were performed on the system in order to achieve a better understanding of the behavior of the coupled system, however, it was not possible to simplify this interaction in the way desired. Several observations are presented which may help in further studies.