SUMMARY Optimal design for tuned mass dampers (TMDs) with linear or nonlinear viscous damping is formulated in order practitioners to directly compute the optimal parameters of a TMD damped structure subjected wind excitations. The tuning frequency ratio and coefficient system installed under 10 white noise excitations are determined by using time-domain optimization procedure, which minimizes structural response. By applying sequence curve-fitting schemes obtained values, formulas TMDs...

This study develops seismic fragility curves for vertical-pile-supported wharves commonly found in the western United States. Nonlinear time-history analyses of a two-dimensional numerical model under two ground motion suites are performed. The results show that jumbo container cranes increase by 10.8% wharf deck drift. By using experiment-based limit states, proposed demonstrate that, at PGA 0.50 g, probabilities exceeding slight, moderate, extensive, and complete states approximately...

Corrosion has been recognized as one of the predominant causes degradation in aging RC bridge columns. This problem may significantly affect flexural and shear capacities even alter failure modes corroded Traditional physics-based simulations used to determine deteriorating capacity are time-consuming experience convergence problems, which hinders rapid efficient fragility analyses region-scale infrastructure for facilitation regional risk assessment. To address issue, this study leveraged...

This paper presents the results from an experimental pushover test on a one-third-scale model of special inverted-V-braced steel frame with zipper struts. Zipper elements are vertical added at intersections braces above first floor and designed to carry upward unbalanced loads resulting buckling braces. As far as writers know, this is such configuration that has been suggested alternate conventional braced frames in American Institute Steel Construction seismic specification for many years....

Experimental testing revealed that installing concealed vertical slits in reinforced concrete (RC) infill walls enabled the RC to behave a more ductile manner (as compared conventional solid walls), leading better seismic performance for partially restrained (PR) steel frame with innovative walls. To understand new system behavior, four subassemblages of frames prescribed slit were tested at 1/3 scale under horizontal cyclic loading and are presented this paper. Three PR, one was fully...

Abstract Field reconnaissance reports reveal the seismic vulnerability of bridge abutment foundations. To reduce time and cost postearthquake repair, modern design specifications allow backwalls to fracture before supporting foundations reach their maximum strength. This strategy enables function as a fuse, thus protecting from experiencing excessive forces damage. paper introduces new modeling scheme capture shear mechanism straight in seat abutments. this end, backwall connection spring is...

Non-ductile reinforced concrete frames have seismic vulnerabilities due to inadequate reinforcing details. Adequately characterizing the performance of these details is critical development analytical models. This study presents a methodology simulate response such with and without fiber-reinforced polymer column jackets. The bond-slip effects between bars surrounding concrete, observed in lap-splice beam–column joints, are modeled one-dimensional slide line models LS-DYNA. model defined...

This study develops the probabilistic seismic response and capacity models for broad collection of standard pile designs that are routinely incorporated into bridges in California. A review state bridge inventory indicates considerable variations design details different types used across multiple eras. For each type, fiber-section-based attached with p-y soil springs built to incorporate nonlinear behaviors materials, a wide array heterogeneous profiles, full-range damage states piles,...

Two one-third-scale three-story models of special inverted-V-braced frames with zipper struts were tested under quasistatic cyclic loads. Zipper utilize a vertical element at the intersection chevron braces and floor beams to distribute unbalanced forces due brace buckling. ground motions representative far-field (Chile 1985) near-field earthquake (Kobe 1995) selected for tests. tests two different amplitudes 1985 Chile conducted on one frame; three 1995 Kobe record other. For each specimen,...

The algorithm of modified predictive control (MPC) is derived with the partial-state concept direct output feedback (DOF) to reduce number sensors for real implementation. feasibility using (MPCwDOF) verified through numerical and experimental study. According MPCwDOF algorithm, online forces are simply generated from actual measurements that multiplied by a prescribed constant gain matrix. An off-line method introduced find systematically efficiently. Numerical examples two systems respect...

Over the past decades moderate/severe earthquakes often caused great damage to bridge decks due their mutual collision and large residual deck offset yielding in traditional steel restrainers. This issue raises a need of developing smart expansion joint with high recentering strength prevent from restore original configuration. Buckling restrained SMA can provide much higher than unconfined (approximately 1.2 ~ 1.5 times), which significantly reduces amount thereby cost proposed herein. The...

Fragility analysis for highway bridges is essential risk assessment of transportation networks exposed to seismic hazards. This study uses detailed three-dimensional nonlinear analytical models a typical California multi-span concrete box girder bridge without and with protective systems develop fragility curves which can be used in regional networks. The as-built model calibrated using responses recorded during the 1979 Imperial Valley earthquake. two retrofitted carried out. reference...

Power outage after an earthquake would cause additional chaos to the existing aftermath, greatly aggravating situation if lasts for extended period. This research aims at developing innovative piezoelectric brace, which provides both passive energy-dissipating and energy-harvesting capabilities—a suppression of structural vibrations conversion vibration energy into reusable electricity. The brace has compression modules that exert compressive loads on material regardless is in or tension....

This paper presents results from two experimental programs of quasi-static testing and dynamic which investigate the re-centering energy-dissipating behavior a one-tenth-scale smart hybrid brace. Smart braces, that tend to prevent soft-story mechanism, restore original configuration can be rapidly rehabilitated, are composed three main components: (1) set superelastic shape memory alloy (SMA) wires anchored in (2) struts with energy-absorbing capabilities, (3) high-strength steel tubes guide...

As the result of research conducted under a NEESR award, new design procedures are being proposed for inclusion in 2010 AISC Seismic Provisions Structural Steel Buildings zipper braced frames. A frame is conventional chevron-braced configuration which intersection points diagonals have been linked with vertical element (zipper strut). The intent elelment to force simulataneous buckling all stories avoid soft-story mechanism typical concentrically Zipper frames considered as viable...