Editor’s Note

The issue opens with a two-part paper by Miranda and Taghavi examining “Approximate Floor Acceleration Demands in Multistory Buildings.” In the first part, the writers propose an approximate method to compute floor accelerations based on an equivalent continuum structure that consists of a combination of a flexural beam and a shear beam. In the second part, the proposed procedure is validated by comparing responses estimated using the approximate method with results obtained from time history analyses of detailed finite-element models of two generic buildings and several instrumented buildings. The study concludes that the approximate method estimates floor accelerations with reasonable accuracy for structures responding in the elastic range. In the next paper, the “Influence of Foundation Flexibility on $R_{\mu }$ and $C_{\mu }$ Factors” is investigated by Aviles and Perez-Rocha. Based on extensive analyses of a single elasto-plastic model, the writers demonstrate that the response is a function of the period ratio of the structure and the site.

Ghalibafian et al. present results from an experimental study on “Seismic Interaction between Flexible Conductors and Electrical Substation Equipment.” Results of the investigation indicate that significant dynamic force amplification is likely due to interaction between the conductors and the equipment. “Seismic Performance of Rectangular-Shaped Steel Piers under Cyclic Loading” is experimentally evaluated by Aoki and Susantha to examine the effects of web-to-flange aspect ratio on ultimate strength, ductility, and energy dissipation capacity of steel bridge columns. In the next paper, Jin and El-Tawil carry out detailed analytical studies on three buildings of varying height to evaluate FEMA-350 seismic provisions for steel panel zones. The study shows that FEMA-350 provisions lead to a low level of panel zone participation than intended in the guidelines. The writers contend that the effect of panel zone deformation on connection response is not well understood and additional research on the subject is needed.

Berman and Bruneau describe the design, testing, and relevant findings from an “Experimental Investigation of Light-Gauge Steel Plate Shear Walls.” It is shown that steel infill flat plates and corrugated infill plates designed as seismic retrofits are effective strategies to improve ductility and energy dissipation while minimizing demands on the surrounding framing. Three design models developed to quantify the increase in ultimate strength of plate girder webs are evaluated by Graciano in “Strength of Longitudinal Stiffened Webs Subjected to Concentrated Loading.” Kosteski et al. report results from experimental tests on “Notch Toughness of Internationally Produced Hollow Structural Sections.” Among other findings, the study notes that the flat face transverse CVN coupon generally results in lower notch toughness than the flat face longitudinal CVN coupon for all HSS production methods.

An endochronic plasticity-based differential equation model is proposed by Clarke in “Non-Bouc Degrading Hysteresis Model for NDP Seismic Design.” The model is shown to reproduce experimental force-deformation behavior with adequate accuracy and lends itself to effective and inexpensive parameter identification. Shao et al. present a “Fiber-Element Model for Cyclic Analysis of Concrete-Filled FRP Tubes.” A two-dimensional, 3-node element with five degrees-of-freedom (DOFS) at each end node and three DOFS at the middle node is proposed for large displacement nonlinear analysis of CFFT beam-columns. The next paper, by Chung and Sotelino, describes “Nonlinear Finite-Element Analysis of Composite Steel Girder Bridges.” A strain decomposition technique is employed to model behavior across the cracked concrete surface such as aggregate interlock and dowel action. The proposed material model is incorporated into ABAQUS, and FE simulations are compared with available experimental results.

Results from an extensive experimental study are reported by Bae et al. in “Inelastic Buckling of Reinforcing Bars.” An empirical model is derived for predicting bar buckling that can be incorporated into steel material models for use in conventional sectional analysis of reinforced concrete members. The use of optical fiber sensors for monitoring structures is demonstrated by De Waele et al. in their paper “Measuring Ground Anchor Forces of a Quay Wall with Bragg Sensors.” Load cells are developed using these sensors and effectively used to measure prestressing forces in a quay wall in Belgium.

Liu and Frangapol introduce the concept of “Time-Dependent Bridge Network Reliability” in evaluating the overall performance of a bridge network and assessing the importance of individual bridges to the network. The range of computed reliability indices that result from updating the assumed load statistics and assumed resistance statistics is investigated by Rosowsky et al. in “Reliability-Based Code Calibration for Design of Wood Members Using LRFD.” A new “Analytical Model for Sheathing-to-Framing Connections in Wood Shear Walls and Diaphragms” that does not require scaling or adjustment and is suitable for both monotonic and cyclic loading is proposed by Judd and Fonseca. The final technical paper in this issue, by Williams and Dym, presents a new approach to “Using Rotations to Obtain Compatibility Equations for Statically Indeterminate Trusses.”

This issue also contains a technical note by Van de Lindt and Rosowsky examining “Strength-Based Reliability of Wood Shearwalls Subject to Wind Load.” The evaluation, which applies primarily to light-frame construction, suggests that the mean drift is close to FEMA-273 life-safety limits for seismic design of wood-frame walls. The issue concludes with a discussion on a paper by Xiao and Wu that appeared in the June 2003 issue. The discussers raise questions on the assumptions made in proportioning the jacket stiffeners. The writers of the original paper indicate that they opted to use the ACI-318 equation as a starting point for the sake of simplicity and also because the objective of the research was to target the retrofit to current code requirements.

Asteris, P. G., Tzamtzis, A. D., and Vouthouni, P. P. (2005). “Earthquake-resistant design and rehabilitation of masonry historical structures.” Pract. Period. Struct. Des. Constr., 10(1).

Bisby, L. A., Green, M. F., and Kodur, V. K. R. (2005). “Modeling the behavior of FRP-confined concrete columns exposed to fire.” J. Compos. Constr., 9(1).

Bortolotti, L., Carta, S., and Cireddu, D. (2005). “Unified yield criterion for masonry and concrete in multiaxial stress states.” J. Mater. Civ. Eng., 17(1).

Cho, S.-W., Kim, B.-W., Jung, H.-J., and Lee, I.-W. (2005). “Implementation of modal control for seismically excited structures using MR dampers.” J. Eng. Mech., 131(2).

DeSantiago, E., Mohammadi, J., and Albaijat, H. M. O. (2005). “Analysis of horizontally curved bridges using simple finite-element models.” Pract. Period. Struct. Des. Constr., 10(1).

Dicleli, M., Albhaisi, S., and Mansour, M. Y. (2005). “Static soil-structure interaction effects in seismic-isolated bridges.” Pract. Period. Struct. Des. Constr., 10(1).

Dilek, U. (2005). “Evaluation of fire damage to a precast concrete structure: Nondestructive, laboratory and load testing.” J. Perform. Constr. Facil., 9(1).

Hamid, A. A., El-Dakhakhni, W. W., Hakam, Z. H. R., and Elgaaly, M. (2005). “Behavior of composite URM-FRP wall assemblages under in-plane loading.” J. Compos. Constr., 9(1).

Sarma, K. C., and Adeli, H. (2005). “Comparative study of optimum designs of steel highrise building structures using ASD and LRFD codes.” Pract. Period. Struct. Des. Constr., 10(1).

Whitehead, P. A., and Ibell, T. J. (2005). “Rational approach to shear design in FRP-prestressed concrete structures.” J. Compos. Constr., 9(1).

Wong, K. K. F. (2005). “Predictive optimal linear control of inelastic structures during earthquake.” J. Eng. Mech., 131(2).

Wongprasert, N., and Symans, M. D. (2005). “Numerical evaluation of adaptive base-isolated structures subjected to earthquake ground motions.” J. Eng. Mech., 131(2).