Analytical models for the characterization of the response of column base connections (i.e. exposed and embedded base plates) are developed and implemented in the Open System for Earthquake Engineering Simulation (OpenSees) software framework. These analytical models are validated against large-scale experimental programs conducted in different research institutions. The suggested analytical models are utilized to assess the performance of Steel Special Moment Resisting Frames (SMRFs) in the Performance Base Assessment/Design Framework. Specifically, this dissertation presents four studies:

1) A new hysteretic model formulation to capture the peculiar flag-shaped cyclic moment-rotation response of exposed base plates is proposed. This model is developed based on the physical processes involved in the hysteresis response. Five tests from a large scale experimental program at UC-Davis are used to calibrate the parameters of the proposed model.

2) A method is detailed to characterize the rotational stiffness of embedded column base connections. The method considers deformations of the components within the connection. The results are assessed against 9 tests from two experimental programs (ay UC-Davis and Brigham Young University).

3) The seismic demands on column base connections are investigated through a series of nonlinear time history simulations on 2-, 4-, 8-, and 12-story SMRFs. The 2- and 4- story frames feature exposed base plate type connections, whereas the 8-, and 12- story frames feature embedded connections. Results indicate that for exposed base plate connections, failure is likely to be controlled by the minimum axial compression accompanied by high moment. When embedded base connections are specified, the response is largely controlled by moment.

4) An approach to simulate the hysteretic and dissipative response of embedded base connections is described. This approach simulates embedded connections as an arrangement of two springs in parallel to reflect moment contributions due to horizontal and vertical bearing stresses. The resultant model is fit to five large-scale tests to calibrate its parameters.

The intention of these four studies is to contribute to a deeper understanding and more accurate characterization of the response of column base connections of Steel Moment Frames subjected to seismic loads.

Based on participant observations and naturalistic interviews I conducted with male bodybuilders at two fitness clubs, I contribute to the literature on social cohesion and frame theory by conceiving of social cohesion as a frame that exists in two modalities: as the positive energy frame and as the negative energy frame. The positive energy frame characterizes social cohesion as the collective harmony that occurs when positive energy perceivers adhere to nonjudgmental, supportive, and celebratory interaction principles. The negative energy frame conceives of social cohesion as something that exists outside of negative energy perceivers in a community of haters (i.e. perceived envious others who are perceived as wishing for the downfall of the negative energy perceiver) that negative energy perceivers do not see themselves being a part of even though they themselves engage in the same negative behavior they criticize haters for. This results in a competitive and unfriendly environment where negative energy perceivers do not trust one another, thus perpetuating the negative energy frame. In addition, I introduce the mobile energy frame to describe the process whereby energy perceiving bodybuilders “take with them” the respective energy frame of their fitness club and use it to inform bodybuilding activities outside of it.

Structural (shear) walls are used worldwide to resist gravity and earthquake loads. In many countries, structural walls commonly are constructed with a rectangular cross section, or a cross section made up of interconnected rectangles, without an enlarged boundary element. In some countries, design practice has resulted in walls that are more slender than those used in the past. For example, in Chile and elsewhere it is not unusual to find rectangular wall edges having thickness of 6 to 8 in. (150 to 200 mm), resulting in floor-to-floor slenderness ratios reaching hu⁄b= 16 or greater. Such walls can be susceptible to overall wall buckling in which a portion of the wall buckles out of the plane. The main objective of this research is to develop a methodology for evaluation of the onset of lateral instability in reinforced concrete slender walls. First, a simplified buckling mechanics solution for prismatic columns under inelastic tension/compression cycles is presented and later evaluated using the results of column tests. Later, three numerical models for buckling in columns are evaluated: nonlinear beam-column elements with fibers, and two-dimensional and three-dimensional nonlinear finite element models. Wall boundaries have strain gradient along the wall length, which would tend to brace the edge of the wall with the result that the simplified mechanics solution may give an over-conservative estimation of the onset of buckling. The theory may also be conservative for walls where the axial force in the boundary elements is not constant along the unsupported height, as may occur where moment gradients occur. To study these effects, analytical models of columns and walls are implemented. A simple approach is proposed to reduce the over conservatism of the simplified mechanics in cases where strain gradients cannot be neglected. Later, two-dimensional nonlinear finite element models are used to analytically reproduce the experimental response of wall tests. These models are used to estimate strain profiles for evaluation of the onset of lateral buckling in slender boundaries. Strain profiles are also estimated from a plastic hinge model. Finally, three damaged buildings in Chile are analyzed using linear models for the buildings and nonlinear models for isolated walls. Both buildings had some buckled walls after the 2010 Maule earthquake. Based on these studies, it is concluded that buckling in Chilean buildings most likely was a secondary failure that occurred after initial crushing of the wall boundaries.