Papers by Lawrence Reaveley
Earthquake Engineering & Structural Dynamics, 2014
Numerical studies of existing buildings demonstrate the effectiveness of nonlinear/inelastic roof... more Numerical studies of existing buildings demonstrate the effectiveness of nonlinear/inelastic rooftop tuned mass damper frames (NRTMDF) used as a retrofit for reducing seismic response. The technique utilizes a rooftop penthouse as a tuned mass damper with mass incorporated as the roof deck of the penthouse while targeted nonlinearity and energy dissipation are introduced through buckling restrained braces (BRBs) linking the penthouse mass to the structure below. The writers summarize numerical studies of ten existing buildings modified with a specifically tuned NRTMDF. The studies demonstrate the effectiveness of the technique that stems from elastic and transient inelastic period shifts enabled by the damper coupled with targeted energy dissipation in the penthouse BRBs. Numerical simulations using response nonlinear timehistory analysis techniques show that for many structures and sites, the NRTMDF decreases peak transient response and overall seismic demand of the original structure. The technique also reduces seismic demand on nonstructural elements and components, manifested as reductions in floor acceleration spectra. Energy methods show that the approach enables significant reductions in energy demand on the original structure through the complete earthquake acceleration history. scaled to reflect BSE-1, BSE-2, and the respective site conditions. Effectiveness of the approach was measured on the basis of observed differences in key output parameters between the undamped and damped versions of each numerical model. Output parameters include rooftop displacement, base shear, story displacement, inter-story drift, rotations (for moment frame beams and shear walls), and damage indices (energy methods). Owing to the volume of output of the ten numerical models, this paper presents key results of the nonlinear numerical modeling for BF-4 and the medium site condition. As a four-story concentrically braced frame structure with a rectangular footprint, this structure is deemed to be representative of the numerical models considered within the complete . Transverse braced frames (symmetric placement), masses, dimensions, and geometry for BF-4. 308
Journal of Performance of Constructed Facilities, 2015
Structures and Infrastructures, 2008
This document provides recommendations to supplement industry standard specifications for structu... more This document provides recommendations to supplement industry standard specifications for structural steel construction of steel moment frames intended for seismic applications. In addition it presents recommended guidelines for implementation of construction quality control and quality assurance programs for these structures. These recommendations were developed by practicing engineers, based on professional judgment and experience, and by a program of laboratory, field and analytical research. While every effort has been made to solicit comments from a broad selection of the affected parties, this is not a consensus document. It is primarily intended as a resource document for organizations with appropriate consensus processes for the development of future design standards and building code provisions. No warranty is offered, with regard to the recommendations contained herein, either by the Federal Emergency Management Agency, the SAC Joint Venture, the individual Joint Venture partners, or their directors, members or employees. These organizations and their employees do not assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any of the information, products or processes included in this publication. The reader is cautioned to review carefully the material presented herein and exercise independent judgment as to its suitability for application to specific engineering projects. These recommended criteria have been prepared by the SAC Joint Venture with funding provided by the Federal Emergency Management Agency, under contract number EMW-95-C-4770.
S S S S Sy y y y ynop nop nop nop nops s s s si ii iis: s: s: s: s: To improve the confinement ef... more S S S S Sy y y y ynop nop nop nop nops s s s si ii iis: s: s: s: s: To improve the confinement effectiveness of FRP composites for square and rectangular columns, shape modification is performed by using prefabricated FRP shells combined with expansive cement concrete. Chemical post-tensioning using expansive cement concrete is used to change
Earthquake Spectra, 2009
ABSTRACT Wood shear walls are the most common element in the lateral force resisting system of re... more ABSTRACT Wood shear walls are the most common element in the lateral force resisting system of residential construction. Recent developments have made the use of staples, as a sheathing to stud connection, much more feasible and practical. Dynamic cyclic tests of wood shear walls using staples as connectors of sheathing to the studs were performed to determine load and displacement capacities. Enhanced details from standard construction were used to improve the performance of the global system including a double sill plate, a new refined panel corner detail, double staples along blocked edges, and backup bolts for hold-downs. The experiments have shown that the stapled wood shear walls with the enhanced details performed at a level above that allowed by the International Building Code-IBC (ICC 2006) regarding peak load capacity but slightly less regarding peak drift capacity.
Journal of Composites for Construction, 2007
... Zihan Yan, Chris P. Pantelides, M.ASCE, Lawrence D. Reaveley, M.ASCE. ... starts to accumulat... more ... Zihan Yan, Chris P. Pantelides, M.ASCE, Lawrence D. Reaveley, M.ASCE. ... starts to accumulate in the concrete core thus increasing the radial expansion (area strain) at a higher rate than the axial strain, and the initial volumetric contraction is reversed until it becomes zero. ...
Journal of Structural Engineering, 1999
In situ lateral load tests of two bridge bents were conducted on Interstate 15 to determine the s... more In situ lateral load tests of two bridge bents were conducted on Interstate 15 to determine the strength and ductility of an existing concrete bridge and the improvements that can actually be achieved using a CFRP (carbon fiber reinforced polymer) advanced composite retrofit. ...
Journal of Reinforced Plastics and Composites, 2003
ABSTRACT Steel plate connectors joining concrete wall panels or horizontal diaphragms are suscept... more ABSTRACT Steel plate connectors joining concrete wall panels or horizontal diaphragms are susceptible to corrosion and behave poorly under seismic loads, due to their low strength and poor ductility. Carbon Fiber Reinforced Plastic (CFRP) composites with their superior strength and resistance to electrochemical corrosion are a practical alternative for connecting precast concrete members. A methodology for designing CFRP connections is developed. The design methodology is based on established models of bond length estimates and laminate theory and correlates reasonably well with results obtained in a related experimental study. The resulting connection design consists of CFRP composite layers adhered to the concrete surface, and four adhesive anchors placed at the boundaries of the precast concrete members.
Journal of Composites for Construction, 2003
ABSTRACT Steel plate connections are frequently used in tilt-up and precast concrete building con... more ABSTRACT Steel plate connections are frequently used in tilt-up and precast concrete building construction to tie adjacent wall panels together for shear and overturning effects, and to provide continuous diaphragm chord connections for wind and seismic loading. These welded connectors perform poorly in regions of high seismicity and are vulnerable to corrosion. Until now, retrofit and repair strategies for in-plane shear transfer strengthening were limited to attaching steel sections across panel edges. In the present paper, an experimental program is described that utilizes carbon fiber reinforced plastic (CFRP) composites to develop a viable retrofit scheme for precast concrete shear walls and diaphragms. Nine full-scale precast wall panel assemblies with CFRP composite connectors have been tested. The results show that the CFRP composite connection is an effective solution for the seismic retrofit and repair of precast concrete wall assemblies and other precast concrete elements, such as horizontal diaphragms, that require in-plane shear transfer strengthening.
Journal of Composites for Construction, 1998
The application of carbon fiber composite jackets for the three columns and cap beam of an existi... more The application of carbon fiber composite jackets for the three columns and cap beam of an existing concrete bridge pier was performed in September 1996. The evaluation of the pier in the as-is condition, the rehabilitation objectives, and the composite wrap design are presented. A ...
Journal of Composites for Construction, 2000
The rehabilitation of RC columns jacketed with carbon fiber-reinforced plastic (FRP) composites f... more The rehabilitation of RC columns jacketed with carbon fiber-reinforced plastic (FRP) composites for improving shear strength, confinement, and ductility has received considerable attention. However, research for improving the shear capacity of beam-column T-joints using FRP ...
Journal of Composites for Construction, 2008
ABSTRACT An experimental research program is described regarding the use of externally applied Ca... more ABSTRACT An experimental research program is described regarding the use of externally applied Carbon Fiber Reinforced Polymer (CFRP) jackets for seismic rehabilitation of reinforced concrete interior beam-column joints, which were designed for gravity loads. The joints had steel reinforcement details that are known to be inadequate by current seismic codes in terms of joint shear capacity and bond capacity of beam bottom steel reinforcing bars at the joint. Lap splicing of beam bottom steel reinforcement at the joint using externally applied longitudinal CFRP composite laminates is investigated. Improvement of joint shear capacity using diagonal CFRP composite laminates is another strengthening scheme employed. The test results indicate that CFRP jackets are an effective rehabilitation measure for improving the seismic performance of existing beam-column joints with inadequate seismic details in terms of increased joint shear strength and inelastic rotation capacity. In addition, CFRP laminates are an effective rehabilitation measure for overcoming problems associated with beam bottom steel bars that have inadequate embedment into the beam-column joints.
Journal of Composites for Construction, 2008
ABSTRACT Precast/prestressed concrete sandwich panels consist of two concrete wythes separated by... more ABSTRACT Precast/prestressed concrete sandwich panels consist of two concrete wythes separated by a rigid insulation foam layer and are generally used as walls or slabs in thermal insulation applications. Commonly used connectors between the two wythes, such as steel trusses or concrete stems, penetrate the insulation layer causing a thermal bridge effect, which reduces thermal efficiency. Glass fiber-reinforced polymer (GFRP) composite shell connectors between the two concrete wythes are used in this research as horizontal shear transfer reinforcement. The design criterion is to establish composite action, in which both wythes resist flexural loads as one unit, while maintaining insulation across the two concrete wythes of the panel. The experiments carried out in this research show that hybrid GFRP/steel reinforced sandwich panels can withstand out-of-plane loads while providing resistance to horizontal shear between the two concrete wythes. An analytical method is developed for modeling the horizontal shear transfer enhancement using a shear flow approach. In addition, a truss model is built, which predicts the panel deflections observed in the experiments with reasonable accuracy.
Journal of Bridge Engineering, 2014
Earthquake Spectra, 1985
The Borah Peak, Idaho Earthquake of October 28, 1983Strong Ground Motion. [Earthquake Spectra 2,... more The Borah Peak, Idaho Earthquake of October 28, 1983Strong Ground Motion. [Earthquake Spectra 2, 51 (1985)]. Suzette M. Jackson, John Boatwright. Abstract. The 1983 Borah Peak, Idaho Earthquake was the largest normal faulting event to occur in the last 20 years. ...
Earthquake Spectra, 2004
ABSTRACT The AISC 2002 Seismic Provisions for Structural Steel Buildings recommend that usage and... more ABSTRACT The AISC 2002 Seismic Provisions for Structural Steel Buildings recommend that usage and sizing of beam flange continuity plates across the column web shall be based on tests. The Recommended Seismic Design Criteria for New Steel Moment-Frame Buildings (FEMA-350) state that unless project-specific testing is performed to demonstrate that continuity plates are not required, moment-resisting connections should be provided with continuity plates when the thickness of the column flange is below a minimum value. One of the preferred moment connections for seismic-resistant steel frames is the reduced beam section (RBS) moment connection, which has performed well under cyclic loads in laboratory testing. To demonstrate the effectiveness of the RBS moment connection without continuity plates in the panel zone, a series of four full-scale tests of exterior beam-column connections was carried out. All materials were A572 Grade 50 steel; the beams were W30 X132, two of the assemblies used W14X283 columns, and the other two used W 18 X 211 columns. The beams were welded to the columns using complete joint-penetration welds. All four tests demonstrated that the RBS connections without continuity plates developed a total interstory drift angle greater than 0.04 radians and met the requirements for special moment frames.
Earthquake Spectra, 2002
ABSTRACT Beam-column joints of nonductile reinforced concrete buildings that were built prior to ... more ABSTRACT Beam-column joints of nonductile reinforced concrete buildings that were built prior to the current seismic code provisions have been investigated using several performance-based criteria. Four half-scale reinforced concrete exterior joints were tested to investigate their behavior in a shear-critical failure mode. The joints were subjected to quasi-static cyclic loading, and their performance was examined in terms of lateral load capacity, drift ratio, axial load reduction in the column at high drift ratios, joint shear strength, ductility, shear deformation angle of the joint, and residual strength. Two levels of axial compressive column load were investigated to determine how this variable might influence the performance of the joint. Specific performance levels for this type of reinforced concrete joint were established and a comparison was made to current design and rehabilitation standards. A limit states model was established, which could be used for performance evaluation or seismic rehabilitation.
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Papers by Lawrence Reaveley