This study focuses on the evaluation of seismic safety of masonry buildings in Turkey by using fragility curves. Fragility curves for masonry buildings are generated by two behavior modes for load bearing walls: in-plane and out-of-plane. By considering the previous research and site investigations, four major parameters have been used in order to classify masonry buildings with in-plane behavior mode. These are number of stories, strength of load-bearing wall material, regularity in plan and the arrangement of walls (required length, openings in walls, etc.). In addition to these four parameters, floor type is also taken into account for the generation of fragility curves by considering out-of-plane behavior mode. During generation of fragility curves, a force-based approach has been used. In this study there exist two limit states, or in other words three damage states, in terms of base shear strength for in-plane behavior mode and flexural strength for out-of-plane behavior mode. To assess the seismic vulnerability of unreinforced masonry buildings in Turkey, generated fragility curves in terms of in-plane behavior, which is verified by damage statistics obtained during the 1995 Dinar earthquake, and out-of-plane behavior, which is verified by damage statistics obtained during the 2010 Elazig earthquake, is combined. Throughout the analysis, ground motion uncertainty, material variability and modeling uncertainty have also been considered. In the final part of the study, a single-valued parameter, called as &lsquo / vulnerability score&rdquo / , has been proposed in order to compare the seismic safety of unreinforced masonry buildings in Fatih sub province of Istanbul and to assess the influence of out-of-plane behavior together with the in-plane behavior of these existing masonry buildings.

This thesis improves a previous kinematic analysis and develops the elastic portion of the analysis of a curved compliant beam. This analysis is used to develop a Pseudo-Rigid-Body Model for the curved compliant beam. The Pseudo-Rigid-Body Model consist of kinematic and elastic parameters which can be used to simplify the computation of the large deflections of the beam as it undergoes spherical motion. The kinematic parameters that are developed are the characteristic radius, Gamma*length, the parametric angle coefficient, c_theta, and the kinematic parametrization limit, Capital_theta_max(Gamma). The elastic parameters developed are the stiffness coefficient, K_theta, and the elastic parameterization limit, Capital_theta_max(K). Additionally, curve fit parameters are developed which enable the calculation of the stress in curved beam as it deflects.

Compliant mechanism theory permits a procedure called rigidbody replacement, in which two or more rigid links of the mechanism are replaced by a compliant flexure with equivalent motion. Methods for designing flexure with equivalent motion to replace rigid links are detailed in Pseudo-Rigid-Body Models (PRBMs). Such models have previously been developed for planar mechanisms. This thesis develops the first PRBM for spherical mechanisms. In formulating this PRBM for a spherical mechanism, we begin by applying displacements are applied to a curved beam that cause it todeflect in a manner consistent with spherical kinematics. The motion of the beam is calculated using Finite Element Analysis. These results areanalyzed to give the PRBM parameters. These PRBM parameters vary with the arc length and the aspect ratio of the curved beam.

The failed anchoring systems of mobile offshore drilling units from hurricanes occurring in 2004 and 2005 established a need to better understand the ultimate pullout capacity and trajectory of scaled model anchors under typical and out-of-plane loading conditions. The six degrees of freedom of small scale drag embedment anchors were studied in a laboratory testing environment with the intent that reasonable trends in anchor behavior will be found. Investigations within this experimental research program demonstrated the in-plane and out-of-plane loading behavior of conventional and prototype scaled model anchors embedded to predetermined depths in two different test beds of kaolinite clay with undrained shear strength profiles constant and increasing with depth. The anchors were loaded to failure in concentric, normal, concentric, shear, eccentric, normal, eccentric, shear, inclined, and drag embedment loading configurations. This series of pullout and drag embedment tests provided a suite of test results indicating behavioral trends of the varying holding capacities and anchor trajectories. Results were compared with similar research presented in the literature and an analytical model predicting out-of-plane loading behavior of similar anchors. It was concluded that increasing eccentricities from both concentric, normal and concentric, shear loading configurations resulted in decreasing bearing capacity factors, confirming the predicted trend from the analytical model for these loading configurations. Trajectories observed for the concentric, normal, concentric, shear, and eccentric, shear loading configurations showed that the anchors tracked straight out of the soil without deviation, but eccentric, normal loading found the anchor tending to track away from the initial loading location. For inclined loads, both anchors to track to whichever direction the anchor faced upon loading. Drag embedment trajectory was found to vary depending on the anchor, as the conventional anchor dove with an applied load and the prototype anchor rose towards the surface. / text

Masonry walls subjected to out-of-plane loading, such as in a seismic event, require reinforcement to improve the ductility of the system. In current masonry construction practice, reinforcement is placed internally and fully grouted. For new construction this can make the wall unjustifiably heavy by not taking advantage of its light, hollow structure. For existing construction, it is difficult to retrofit using this technique. Additionally, the reinforcement is located close to the neutral axis which reduces its effectiveness. Fiber-Reinforced Polymer (FRP) bars, strips and sheets are becoming increasingly popular in construction applications due to their noncorrosive nature and ease of installation. Also, stainless steel bars are used where the structure is exposed to a corrosive environment but have not found wider application for masonry structures. This study is an experimental investigation of the structural performance of masonry walls reinforced with Near-Surface-Mounted (NSM) FRP and stainless steel reinforcement under out-of-plane bending. Additionally, walls with Externally Bonded (EB) FRP sheets were tested. The study simulates retrofitting applications and also proposes the NSM technique for new wall construction, using pre-grooved blocks, in lieu of the conventional method of internal reinforcing and grouting. To accommodate the NSM reinforcement, the grooves in the masonry blocks were aligned with ducts used to anchor the NSM reinforcement in the concrete footing. Seven wall specimens were tested, including walls reinforced with conventional and stainless steel bars, glass-fibre reinforced polymer (GFRP), and carbon-FRP (CFRP) reinforcement. The study demonstrated the feasibility and effectiveness of the NSM technique for new construction. Walls with NSM reinforcement showed a superior performance to those with EB reinforcement. It was shown that increasing the FRP reinforcement ratio may result in a change of failure mode, and as such, the increase in strength may not be proportional to the increase in reinforcement ratio. NSM steel-reinforced walls showed a superior performance in terms of strength, stiffness and the ductility associated with the formation of a plastic hinge at the base. / Thesis (Master, Civil Engineering) -- Queen's University, 2010-05-31 06:24:20.976

Ocean environments with sloped seafloors can give rise to sound paths that do not remain in a constant plane of propagation. Numerical modelling of sound fields in such environments requires the use of computer models that fully account for out-of-plane sound propagation effects. The inclusion of these three-dimensional effects can be computationally intensive and the effects are often neglected in computer sound propagation codes. The current state-of-the art in sound propagation modelling has seen the development of models that can fully account for out-of-plane sound propagation. Such a model has been implemented in this research to provide acoustic consultants JASCO Applied Sciences with an important tool for environmental noise impact assessment in complicated marine environments. The model is described and validation results are shown for benchmark test cases. The model is also applied to study three-dimensional propagation effects in measured data from a realistic ocean environment. Particular analysis techniques assist in the interpretation of the modelled sound field for this physical test environment providing new insight into the characteristics of the test environment. / Graduate

About half of the building stock in Turkey is masonry type and one fourth of the building stock is one-storey brick type masonry buildings. Especially the rural masonry houses are commonly constructed by their own residents without any engineering knowledge. Traditional masonry houses usually have heavy roofs which generate large lateral forces on walls during earthquakes. Readily available retrofitting techniques are mostly complicated and costly making it not feasible for uneducated poor residents to strengthen their own houses. The aim of this thesis is to develop a new alternative strengthening technique using scrap tires that is economic and easy to apply on the walls of one-story masonry houses. In order to investigate the usage of scrap tires for masonry wall post-tensioning, forty three scrap tire rings (STRs) from nine different brands and nine rim-rings direct tension experiments were conducted. The average tensile load capacities of STRs and rim-rings were found as 132.6 kN and 53 kN, respectively. Six strip walls (i.e., four brick- and two briquette-walls) strengthened by applying post-tensioning loads with STCs and hybrid system were tested in out-of-plane bending direction. The out-of-plane capacity of the brick and briquette walls increased up to about 9 times and 5 times with respect to their nominal capacities, respectively. Finally, two-full scale traditional masonries were tested by the tilting table. The capacity of strengthened house increased 75% with respect to the unstrengthened one. The results obtained form the conducted tests are highly promising and suggest that the method can be used as a low-cost and simple strengthening technique for seismically deficient single storey, masonry type houses.

The behavior of wood shear walls has been the focus of researchers and engineers for many years due to their availability in the North American construction landscape. A review of the established literature showed that most of the research have focused on the shear wall behavior as a whole with no investigation specifically targeting the individual components of its deflection. Also, little to no attention has been given to the investigation of the cumulative effects especially when the out-of-plane diaphragm stiffness is considered. The current study aims at investigating the effects of construction details variation on the behavior of the shear walls and evaluating whether the current deflection equation, as per wood design standard (CSA 2014) can adequately predict the overall wall stiffness. A total of 27 full-scale single-storey walls, with different construction details and aspect ratios, were tested under either static or monotonic (as both are the same) loading. The parameters that were varied in the testing were the stud size and spacing, nail diameter and spacing, sheathing panel type and thickness and hold-down anchoring system/type. For the two-storey walls, two different loading cases were considered, namely where the load was applied at the top or bottom storey only. The results showed that the strength and stiffness correlated almost directly to the inverse of the wall aspect ratio. There was no clear trend when considering the effect of the walls’ aspect ratios on ductility. Unexpectedly, walls with aspect ratios not permitted according to the wood design standard (4:1 and 6:1) followed similar strength and stiffness trends and had sufficient ductility ratios as those with smaller aspect ratios. This observation explains in part some of the discrepancies found between engineering calculations and behavior of actual building with light frame wood shear walls. Significant discrepancies were found when comparing the various deflection constituent with those estimated using the design expression. Adding more end studs and changing the size of the studs had no significant effect on the overall wall capacity and little effect on its stiffness. Reducing the stud spacing had, as expected, no effect on the wall capacity; however, the results showed that the bending stiffness was affected by the overall number of studs in the wall and not solely by the end studs. Shear walls sheathed with plywood panels exhibits slightly higher peak load and initial stiffness than those with OSB, which was mainly attributed to the greater panel thickness, and possibly density, of the plywood. Both sheathing types provided similar levels of ductility, as expected. Thicker sheathing increased the capacity and stiffness of the wall with no significant change observed in ductility ratio. The wall strength was significantly affected by the nail diameter and nail spacing, but no difference was observed when the nail edge/end distance was increased. The results also showed that discrete hold-down system behaved in a non-linear manner with a significantly greater initial stiffness than that assumed in design. The study also showed that having continuous hold-down connections has a positive effect on the capacity, stiffness and ductility of the wall when compared with discrete hold-downs. Having no hold-down adversely affects the wall capacity and stiffness, but did not affect the ductility of the wall. For the two-storey walls, the deflection estimated based on the cumulative effect assumption showed slight differences when compared with that observed in the experimental study. It was observed that the majority of the cumulative effect stems from the rigid body rotation due to deformation in the hold-down devices. A Computer shear wall model (through SAP2000) was developed using linear “frame” and “membrane” elements for the framing and sheathing members, respectively, whereas the sheathing to framing nails and hold-down were modeled using nonlinear springs. It was found that the model was capable of predicting the peak load, ultimate deflection and yield loads with reasonable accuracy, but overestimated the initial stiffness and ductility of the walls. In general, when the force-displacement curves were compared it was evident that the model was capable of predicting the wall behaviour with reasonable accuracy. When investigating the cumulative effects using the model, the results clearly showed that the assumption of cumulative effects due to rigid body rotation is valid for stacked shearwalls with no consideration for the floor diaphragm. The effect of the diaphragm on the behavior of the shear walls, in particular its out-of-plane rigidity was simulated by modeling the floors as beam. The out of plane stiffness of the shear walls was investigated for idealized (infinitely stiff or flexible) as well as “realistic”. The results showed reductions in the shearwall deflection in the magnitude of approximately 80% considering the out of plane rigidity of the diaphragm. It was also concluded that considering conservative estimates of out of plane stiffness might lead to a very significant reduction in deflection and that assuming the floor diaphragm to be infinitely rigid out of plan seems reasonable. For diaphragms supported on multiple panels further reduction in the deflection was observed. More work, particularly at the experimental level, is needed to verify the finding obtained in the numerical investigation related to the effect of out of plane diaphragm stiffness.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第18588号 / 工博第3949号 / 新制||工||1607(附属図書館) / 31488 / 京都大学大学院工学研究科マイクロエンジニアリング専攻 / (主査)教授 田畑 修, 教授 西脇 眞二, 准教授 土屋 智由, 教授 引原 隆士 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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