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Diaphragm seismic design methodology

diaphragm seismic design methodology Minimum reinforcing for the diaphragm and pile cap are shown, and this supplement includes design methodology and example calculations for piles and The traditional diaphragm design method assumes the axial chord forces developed in framing members under in-plane loading are carried only by the perimeter elements. Auto Diaphragm is an enhanced plug-in software for seismic analysis of RC floor diaphragms using strut and tie method. 1. 2. The Vision of this project is to develop and validate a seismic design methodology for tall wood buildings that incorporates high-performance structural and nonstructural systems and can quantitatively account for building resilience. ) are defined the load combinations. This seismic technical guide (STG) is intended as a resource for design professionals, to promote more uniform criteria for plan review and jobsite inspection of projects. In addition, two separate seismic The Diaphragm Seismic Design Methodology is an industry-endorsed comprehensive seismic design methodology for precast concretefloor diaphragms, and winner of The project has been called Diaphragm Seismic Design Methodology (DSDM). ii. It also provides certain aspects of computer software modeling against seismic loads and shows the necessity of seismic upgrading in a steel moment-frame building. 14 Internal Stability Pg. Project Overview. Basic design concepts utilized in the bulletin were derived from "The Methodology for Mitigation of Seismic Hazards in Existing Unreinforced Masonry Buildings," by ABK, A Joint Venture, under National Science Foundation contract number NSF-C-PFR 78-19200. A. Doctoral dissertation, The University of Auckland, New Zealand Google Scholar 14. 2. The dual seismic model is used in special cases, mainly in structures of slabs and walls containing large holes behaving as sensitive ‘necks’ for carrying horizontal seismic forces Dear All, Just a brief introduction about the Diaphragm Design for Lateral Forces in case of Major Earthquake Areas: Please correct me where I am wrong: There are two types of forces in a member 1- Out of Plane Forces (out of plane behavior) 2- Inplane Forces (inplane behavior) Followings are the The evaluation method will be flexible diaphragm analysis as per IBC, rigid diaphragm analysis (torsion) adapted from Seismic Design Handbook and a two dimensional adaptation of a stiffness method. Neelakantan et. - 24 - Diaphragm Design Values of mode shape factor zs 0. DESIGN FORCES, METHODS OF ANALYSIS AND DRIFT LIMITATIONS 5. 2 Executive Summary Pg. Strength level design loads can be estimated by multiplying the allowable stress design seismic loads, shown in Figure C4. This STG indicates an accept-able method for achieving compliance with applicable codes and regulations, although other methods proposed by design professionals may be C2. elastic design. design of diaphragms involves the 3-dimensional structure with interactions between the vertical lateral force resisting structures (moment frames, walls or braces) both horizontally and vertically. Ventura Seismic Design of Multistorey Concrete Structures 7 Torsional sensitivity if the ratio B > 1. The design factors include diaphragm force amplification factors Ψ and diaphragm shear overstrength factors Ω v. This methodology is based on a North American See the attached examples and video to really help better understand general diaphragm design better. The study focuses on application of Performance based Seismic design method to 10 storied frames with floating columns. The UBC permits both the Allowable Stress and Strength Design methods. 5. . , more glass and larger openings), increased building heights, and multi-story shear wall effects. 1 or the component force from section 13. Seismic Design Methodology : 20-2 . Principios Generales y métodos de cálculo. Diaphragm classifications for different seismic zones A framework for the design methodology was proposed by the research team that incorporates multiple diaphragm classifications through choices of different overstrength factors, different ductility detaling requirements, and diaphragm span limitations. 4-4 Determine the Seismic Design Category A thru D Note: The more severe of the two SDC governs the design: 1. • Knee braces as seen here for lateral have no code design procedure for seismic. In order to activate the diaphragm, these forces need to be transferred from the façade fixings into the diaphragm plate. There are two types of abutments which are employed in bridge construction namely: monolithic as shown in Figure-1 and seat type as it can be seen in Figure-2. The research work is composed of four major parts:(1) Developing 3D NLTDA analytical model for diaphragm-sensitive precast concrete structures: The 3D structure model is extended from a 2D FE diaphragm model This modification has also been accepted for inclusion in ASCE 7-16. 1] In the Standard of Construction Designs. Because the structure has significant horizontal and vertical irregularities, and is in a high seismic area of southern California, design codes specified three methods of analysis: (A) Modal Response Spectrum Analysis (MRSA) for structures with horizontal irregularities; (B) Tank Hydrodynamics for water basins; and (C) Equivalent Lateral Force (ELF) for regular structures. Treatments of wingwalls, approach slabs, and railings are also shown on the drawings. Accurate calculation of diaphragm deflection is important to engineers because excessive deflection may cause serviceability issues or overall failure of the structure. Archetype designs are developed under ASCE/SEI 7-10 and this study’s proposed approach to develop design methodologies uses the FEMA P-695 methodology to evaluate building performance. 2 SCOPE This code covers the requirements for seismic analysis and design of various building Noting that all diaphragms are flexible to some degree, and that this flexibility can lead to unconventional force and displacement patterns in a building during seismic excitation, there still exists a need to thoroughly characterise the seismic response of buildings with very flexible diaphragms for their proper design. Carradine, J. 3. 1 and 2. R. Diaphragm Seismic Design Methodology. 2, American Institute of Steel Construction (AISC) 341, Section D1. 5. (c) All masonry or concrete walls greater than 1. e. Such a design philosophy can result in inefficient/uneconomical retrofits. Lateral loads are usually wind and earthquake loads. Seismic Design Methodology for Precast Building Diaphragms. The maximum wall height is controlled by the loadings and slenderness effects. engstruct. -10,000-8,000-6,000-4,000 2,000 0 2,000 4,000 6,000 8,000 10,000-6 -4 -2 0246 As the next generation of seismic design methodology, performance-based seismic design (PBSD) method requires a structure satisfy multiple preselected performance levels under different hazard levels. Inadequate shear, bending strength, and stiffness are some of the most common diaphragm deficiencies. Restrainers at Hinges and Bearings : 20-4 . The seismic force distributed to the shear wall at any diaphragm level shall be the lesser value calculated as: i. He has worked for both Caltrans and private consulting firms performing bridge structural design, project management, and applied research. For a diaphragm that is designated as rigid, the lateral force is distributed to the supporting shear walls according to their relative stiffness, with consideration of additional shear force due to torsion for seismic design. 2 DESIGN METHODS: Design of wood structures to resist seismic forces shall be by one Deflections and Element Design Forces. The collector design force is designated as FC and in a general sense it consist of compression and tension collector portions and the portion of diaphragm shear force along line bc, respectively, designated as (FC)comp, (FC)tens, and Vd. This design methodology recognizes that diaphragm inertial forces during earthquakes are highly influenced by higher dynamic vibration modes and incorporates the higher mode effect into the diaphragm seismic design acceleration determination using a first mode reduced method, which applies the response modification coefficient only to the first Semi Rigid or S&T Diaphragm forces are extracted from within the diaphragm using section cuts or axial S&T forces. A new seismic design methodology for precast concrete diaphragms has been developed and incorporated into the current American seismic design code. 2015 SDPWS includes provisions to coordinate with AC468 applies to the alternative seismic design methodology of horizontal precase concrete diaphragms mandatory in buildiings assigned to Seismic Design Category (SDC) C, D, E, or F, and optional in SDC B. The seismic excitation is input in form of ‘Design Ground Response Spectrum’ provided in building codes rather than commonly expected way of using groundmotion time-histories. e. 5 PDH Credits. The omission of both the MRS base shear and the diaphragm force is an oversight that should be corrected in the next edition of ASCE 7 (a code-change proposal is in process with the seismic subcommittee). Academic & Science » Geology. 12. 75, then structure shall be assigned to SDC “E” or “F” (see Step 8 below) ASCE 7-05 Equation 11. 2. When considering diaphragms of MSMBs, similarities can be drawn from precast concrete diaphragm design practices, where the functionalities of the peripheral chord reinforcement, shear connectors and anchorage elements of precast concrete diaphragms are required to be taken up and shared by each inter-module connection within the diaphragms of MSMBs. Diaphragm tests conducted as part of the CUREE-CalTech Woodframe Project(Design Methodology of Diaphragms,J. Diaphragms are classified as either flexible or rigid in the US design codes [2][3] for the purpose of distributing the design seismic forces to the shear walls. Ghosh. A new seismic design methodology for precast concrete diaphragms has been developed and incorporated into the current American seismic design code. Alternate Approach. design base shear from Section 12. Reinforced Concrete Works. 2SDSIwpx, where wpx ¼ 200 kN is the seismic weight tribu-tary to the building’s second floor (ASCE 2010). Floor and wall pressure loads can then be conveniently applied to the panel s as a single value which is automatically decomposed to beam or column elements. 2 FEMA P695 METHODOLOGY OVERVIEW FEMA P695 is a methodology to evaluate seismic performance factors that include the response modification factor (R-factor), the system overstrength factor, and the deflection amplification factor for seismic design in the US. Easterling, 2003) show that the effect of blocking is significant, but that unblocked diaphragms do resist con- [3] D. 2 Rigid Diaphragm Method without Torsion – This method is used to distribute the story lateral load between the shear walls based on the relative shear wall stiffnesses. Holombo is a recognized leader in the development of seismic resistant precast/prestressed concrete bridge design. 6R-19 and ACI 318-19. The example will illustrate implementation of the new ASCE 7-16 diaphragm design force provisions as well as a discussion of other new research developments on large diaphragm 1) Elastic Design Method • Based on lower-bound strength of components • Following new ASCE 7-16 alternative diaphragm method to determine elastic seismic diaphragm force demands 2) Capacity-Based Design Method • Using designated yielding connections with overstrength design of non- desirable limit states. S. The information available specific to diaphragm design in the North American CFS design standards (AISI S240 & S400) is based on limited experimental work and the extrapolation of design methods developed for the wood industry. A performance level is an expression of the maximum desired extent of damage to a building. Floors and roofs are commonly referred to as “diaphragms” in seismic design. Diaphragm walls are most deep structures their design and analysis should concern with the effect earthquakes. Seismic Criteria for Stage Construction : 20-3 . It was determined that the superstructure-to-substructure connection did not provide That work, in turn, followed a multi-year study summarized in FEMA P-1026 which concluded that RWFD buildings are common and current seismic design methods are inadequate. Two examples of a horizontal diaphragm used to transfer lateral loads to the foundation during a seismic event. Bull, Understanding the Complexities of Designing diaphragms in Buildings for Earthquakes, Bulletin of the New Zealand Society for Earthquake Engineering, 37 (2) (2004 One option for developing the design methodologies for CLT dia-phragms is to reference a research program completed for precast-concrete diaphragms [21,22]. The paper presents the general approach of diaphragm walls design under EC 8 and the application to the case of a diaphragm In the 2018 IBC, he adds, the design methodology will be mandatory for precast concrete used as horizontal diaphragms in buildings assigned to Seismic Design Category (SDC) C, D, E or F, and optional in SDC B according to ASCE 7-16. Webinar (July 13): Changes to the Seismic Design Provisions of ACI 318-19 [10-Pack] On-Demand Course: Use of ASTM A1035/A1035M Grade 100 (690) Steel Bars for Structural Concrete According to ACI 439. S. diaphragms or braced frames. For buildings without crosswalls, IKCSW d / 2. It is very important for a structural designer to thoroughly understand each of these parameters to be able to come up with a convincing design. This research project will give a brief presentation about earthquake resistant design and the methodology about seismic evaluation and rehabilitation of existing structures. 3. W A multi-university research team and an active industry task group comprises the Diaphragm Seismic Design Methodology (DSDM) Consortium. The experimental phase of the project1 culminated in July 2008 with the shake-table testing of a three-story, precast concrete building. Dolan, D. An important feature of this methodology is the way of inputting seismic excitation to structures. The research is a closely integrated analytical and experimental effort intended to significantly advance knowledge of the seismic behavior of precast floor diaphragms with the specific objective of producing an appropriate seismic design methodology for eventual code implementation. 1. 2011), which is the controlling ASCE 7-10 diaphragm design load 0. The life-safety performance criteria are intended to ensure that the bridge does not collapse under the design earthquake; however the bridge is expected to sustain significant damage. 5z S (1 – 1/n) Γm2= 0. To determine the shear load on a simply supported diaphragm (i. al (1992) [8], a balanced seismic design concept for anchored retaining walls is presented in this study. A one-half scale three story precast concrete diaphragm will be tested on the shake table at UCSD to investigate the behavior of long-span precast concrete diaphragms under seismic excitation. e. This will be accomplished through a series of research tasks planned over a 4-year period. 19 Summary of Calculations Pg. • Tables are for DFL or SYP – need to adjust values if framing with wood species with lower specific gravities. If a greater eccentricity is desired, it may be specified in the Diaphragms spreadsheet in RISA-3D. Diaphragm Abutments : 6-1 . Mr. The 2D numerical modeling framework is based on a three step sub-structuring approach including: (1) a hysteretic response database for diaphragm connectors, (2) a 2D inelastic roof diaphragm model incorporating hysteretic connector response and (3) a simplified 2D building model incorporating hysteretic diaphragm model response. Bott, W. The The methodology is presented as proposed AASHTO guidelines for performance-based seismic bridge design with ground motion maps and detailed design examples illustrating the application of the proposed guidelines and maps. CLT panels in of new seismic design and retrofitting strategies. This webinar will cover the basic design of cold-formed steel light frame diaphragms as envisioned in the provisions articulated in AISI S100-16, North American Specification for the Design of Cold-Formed Steel Structural Members, 2016 Edition; AISI S230-19, North American Standard for Cold-Formed Steel Framing―Prescriptive Method . Most building designs use some form of diaphragm at every floor and at roof level. The Steel Diaphragm Innovation Initiative (SDII), which is a cooperative effort between industry, academia, and federal research, is providing a In the 2018 International Building Code (IBC), this design methodology will be mandatory for precast concrete used as horizontal diaphragms in buildings assigned to Seismic Design Category (SDC) C, D, E or F, and optional in SDC B according to ASCE 7-16. Each floor diaphragm immediately above such a target story, and 3. Evaluate vulnerability of structures with previous poor seismic performance 4. The Steel Deck Institute Diaphragm Design Manual (SDI DDM) provides further guidance on diaphragm design. The diaphragm strength and deflection is evaluated only in the north-south direction for seismic loads. 1. 7. 10 (NIST GCR 14‐ 917‐32) Seismic Design of Wood Light ‐ Frame Structural Diaphragm Systems : A Guide for Practicing Engineers Today in U. CLT Horizontal Diaphragm Design Example This design example is intended to evaluate a cross laminated timber diaphragm using Structurlam SLT3 Panels. “ Effect of Diaphragm Flexibility on Seismic Response of Building Structures”, In proceedings of 8th world conference on earthquake engineering. This design methodology recognizes that diaphragm inertial forces during earthquakes are highly influenced by higher dynamic vibration modes and incorporates the higher mode effect into the diaphragm seismic design acceleration determination using a first mode reduced method, which applies the response modification coefficient only to the first Allowable Stress Design of Reinforced Diaphragm Walls The allowable stress design (ASD) methodology for reinforced diaphragm walls is similar to reinforced single wythe wall design and is discussed in TEK 14-7C, Allowable Stress Design of Concrete Masonry (ref. 1. There are a few other methods (FEMA 154, ASCE 31, FEMA 356) to evaluate existing structures but non specifically designed for single-family dwellings. Safely Spreading the Benefits of Precast Construction: The Diaphragm Seismic Design Methodology Project Author: NEHRP - National Earthquake Hazards Reduction Program Subject: SeismicWaves July 2009 - How the National Earthquake Hazards Reduction Program Is Advancing Earthquake Safety Created Date: 20090731202531Z The proposed design approach was also validated through the FEMA P695 methodology for a large set of building archetypes varying in building size, diaphragm aspect ratio, roof diaphragm construction, seismic hazard, framing and sidelap connector types. Summary. The scope of this Guide is restricted to cast-in-place concrete diaphragms, either 1. In addition to meeting the basic safety of objective of preventing loss of life, Performance Based Seismic Design can provide a cost-effective means to: Reduce earthquake financial loss due to structural and nonstructural damage. 25 In conclusion, methods (a) and (b) for the seismic design of earth dams and tall embankments are, in reality, clearly interrelated. On-Demand Course: Learning from the Nepal 2015 Earthquake Seismic Design Methodologies for the Next Generation of Codes book. g. ASCE 41-17 seismic design typically requires steel deck diaphragms to be designed (retrofit or new design) as “force-controlled”, i. A new RWFD design methodology is proposed providing Past problems in these buildings have been the repeated a rational approach to improve performance in these failures of the walls’ anchorage to the diaphragm, and In the 2018 IBC, he adds, the design methodology will be mandatory for precast concrete used as horizontal diaphragms in buildings assigned to Seismic Design Category (SDC) C, D, E or F, and optional in SDC B according to ASCE 7-16. The balanced seismic design enhances the seismic diaphragm area, or changes in effective diaphragm stiffness of more than 50 percent from one storey to the next. 4. Elements of the seismic force- resisting load path from each such diaphragm through the foundation. Concept of Seismic improvement The proposed method of improvement with flexible end diaphragms has been developed based on the capacity design. While, in the new This Guide covers seismic design issues pertaining to Seismic Design Category B up through Seismic Design Category F. This standard sets down requirements for the general structural design and seismic design loadings for structures within any of the following categories : (a) All buildings having a floor area greater than 20 square metres. The tables are calculated based on Steel Deck Institute (SDI) Diaphragm Design Manual, Third Edition (DDM03). results for diaphragm samples. However, historical to determine whether adequate load path and capacity are provided to transfer seismic loads. Seismic Design of Multistorey Concrete Structures 1. The provisions are set to replace current ASCE 41 guidelines which do not recognize the potential for ductile performance in steel deck diaphragm systems with performance measures w = The width of a diaphragm or shear wall in the direction of application of force measured as the sheathed dimension of the shear wall or diaphragm. The actual diaphragm’s stiffness is calculated as k 2, (5) k 2 = 3 B 2 G d L 2 where B 2 is the width of actual diaphragm and L 2 is the span of actual diaphragm. Direktorat Jenderal Bina Konstruksi. E. Methods for The promise of performance based seismic engineering is to produce structures with predictable seismic performance [5]. [4] D. This could be the case, for example, when stiff wall-piers that can difficultly be detailed to have a stable ductile response are used as substructures. Floor diaphragms in newer timber buildings are nearly always particleboard or plywood. Traditional diaphragm design procedures assume the diaphragm demands are reduced by the response modification factor, R, which is associated with the vertical system alone. A shear wall resists loads parallel to the plane of the wall. 00 / 2 votes) Translation Find a translation for Safely Spreading the Benefits of Precast Construction: The Diaphragm Seismic Design Methodology Project Author: NEHRP - National Earthquake Hazards Reduction Program Subject: SeismicWaves July 2009 - How the National Earthquake Hazards Reduction Program Is Advancing Earthquake Safety Created Date: 20090731202531Z In Portugal the Portuguese Standard ENV 1998-1-1 considers four seismic zones: A, B, C and D. The knowledge required to create the design methodology was obtained through an integrated active 10 member Diaphragm Seismic Design Methodology (DSDM) Task Group. 23 Allan Block & Huesker Synthetics Pg. , Lu, L-W. Wind loads are normally idealized as uniformly distributed line loads applied to the diaphragm edges. The work contributed to the develop-ment of a new section for seismic diaphragm design in ASCE 7-16 [23] and the new diaphragm force reduction factor, R s [24]. This approach relies on forcing yielding of the roof diaphragm as the predominant inelastic response under extreme ground shaking instead of the vertical elements of the seismic force-resisting system (SFRS). Balai Penerapan Teknologi 1. Seismic design method [7]. 5. 9). structure/diaphragm interface. The design hazard will be based on USGS Seismic maps from FEMA 356. 3 Testing Summary/Results Pg. Diaphragm Seismic Design Methodology. Zone A is the one of greater seismic risk and includes the Lisbon area and the coastline South of Lisbon down to the Algarve. Key words: Performance Based Seismic Design, Pushover analysis, Diaphragm Discontinuity, Performance Objectives, RCC Buildings I. The technique as a formal concept is a CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): Evidence indicates that the dynamic behavior of Rigid Wall – Flexible Diaphragm (RWFD) structures is dominated by the diaphragm’s response instead of the walls ’ response, and this is a significant departure from the underlying assumptions of the widely used equivalent lateral force method in current building codes. Evaluate post-earthquake structural safety 5. The methodology, applicable to topped and pretopped diaphragms, was developed on the basis of extensive analytical and experimental research [3], and possesses key features that address aspects not treated adequately in previous design provisions, including: (i) diaphragm design forces that horizontal diaphragms resisting seismic and wind forces. 3 for buildings designed with Buckling Restrained Braced Frame systems 0. Such analysis shall result in a system that provides a complete load path capable of transferring loads from their point of origin to the load- resisting elements. A new seismic diaphragm design methodology has been developed for precast concrete floor diaphragms. 61 RP3-4. Also presented are step-by-step procedures on how to determine in-plane diaphragm forces due to wind, general structural integrity, seismic, soil, transfer, anchorage, and An envelope analysis is permitted as an alternative to semi-rigid modeling whereby distribution of horizontal diaphragm shear to each vertical seismic force resisting element is the larger of the shear forces resulting from two separate analyses where the diaphragm is idealized as flexible and the diaphragm is idealized as rigid. Although WFSFD come in many Seismic Design in Steel -- Concepts and Examples (Part 5): Design Example Setup (L1) 1. Wilson A (2012) Seismic assessment of timber floor diaphragms in unreinforced masonry buildings. The magnitudes of seismic forces which develop in floor diaphragms were investigated in this report to enable the development of a desktop floor diaphragm force design method for use in a structural design office. The design factors include diaphragm force amplification factors Ψ and diaphragm shear overstrength factors Ω v. The shear strength tables can be generated in Nominal or LSD for wind and seismic applications. 4. Understanding the different seismic analysis parameters is an integral part of the seismic analysis. org Diaphragms. Finally, the end diaphragms of steel girder bridges were designed for seismic loads to determine whether the current design methodology provides adequate resistance. Other analytical methods, such as Strut-and-Tie Diaphragm (S&TD) analysis, are also permissible. The reinforced concrete (RC) diaphragm damage observed during the Northridge earthquake (1994) has motivated numerous analytical and experimental studies focused on evaluating the seismic performance of this important building component. 5 metres in height. In each of these methods the dia-phragm force is considered to be a distributed load on the diaphragm, Diaphragms shall be designed for both the shear and bending stresses resulting from design forces. Three classifications were proposed: Victaulic Seismic Testing Videos; Diaphragm Seismic Design Methodology Videos; SC-MRF Videos; SC-CBF Videos; Impact Forces from Tsunami-driven Debris Videos; Advanced Damping Systems Videos; In The News Media; EOT. Determine methods for improving seismic performance of existing structures NEHRP Seismic Design Technical Brief No. 2010). diaphragm shear design is based on the length of the wall or frame instead of on the overall diaphragm length. 2. The knowledge required to create the design methodology was obtained through an integrated analytical and experimental research project using two Network for Earthquake Engineering Simulation (NEES) equipment sites. Two alternate design methodologies, where the period is not restricted by code limitations and where the diaphragm force is limited to the equivalent shear force calculated with RdR o = 1. Prevent Shear Failure Diaphragm Seismic Design Concept Fpx 54 The seismic design methodology specifically recognizes the dynamic response of these structures as being dominated by dynamic response of and inelastic behavior in the diaphragm. Vertical elements of the seismic force -resisting system (SFRS) in each target story in which the existing SFRS relies on wood-frame elements, and 2. Shear on Diaphragm Moment on Diaphragm Design Method 1. Gardiner, Design Recommendations and Methods for Reinforced Concrete Floor Diaphragms Subjected to Seismic Forces, PhD Thesis, University of Canterbury (2011). The research program is the focus of this paper, including the integrated research approach, the project's physical scope, and the specific analytical and experimental research activities. K. ” (CBC 2010 1604. A new seismic diaphragm design methodology has been developed for precast concrete floor diaphragms. It also applies to the qualification of propriet The design seismic accelerations are applied on each mass m, resulting to seismic forces F=m×a used for the calculation of the structure's stress resultants. Since SDC A is exempt from seismic design, it is not specifically addressed, although many of the diaphragm analysis and design methods described herein are applicable to the design of diaphragms to resist wind forces and provide structural This paper presents an analytical study used to establish design factors for a new seismic design methodology for precast concrete floor diaphragms. Column Analysis Considerations : 6-5 . Seismic loads can be considered as area loadsapplied to the whole diaphragm surface. These methods have their merits but they are generally too complex to be structural engineering used to prescribe building loads and outline design methodologies. Figure 4. In many jurisdictions, the International Building Code and International Residential Code govern the design of shear walls. Pier Walls : 9-3 . The purpose of this Design Guide is to provide explanatory material based on the provisions of that chapter for diaphragms in buildings assigned to any Seismic Design Category. , chords, collectors, drags). ABSTRACT Development of a Seismic Design Methodology for Precast Floor Diaphragms -- CMS 0324522 PI: Robert Fleischmann, Arizona A consortium comprised of the University of Arizona (UA), the University of California San Diego (UCSD), and Lehigh University (LU), together with the Precast/Prestressed Concrete Institute (PCI) proposes a collaborative research project to develop a comprehensive The research behind Diaphragm Seismic Design Methodology (DSDM) integrates finite element analyses of a diaphragm with full-scale reinforcing detail experiments and shaking table system tests. A comprehensive study on the seismic response of flexible diaphragm RC wall buildings was undertaken. seismic design provisions, i. The Precast/Prestressed Concrete Institute (PCI) is conducting a large "area of emphasis" project, jointly funded by National Science Foundation (NSF), with an overall objective of developing a comprehensive seismic design methodology for precast concrete floor diaphragms. 2 gives a much simpler definition for “Diaphragm” that permits more The development of displacement based approaches for earthquake engineering design appears to be very useful and capable to provide improved reliability by directly comparing computed response and expected structural performance. 7 for buildings designed with Moment-Resisting Frame systems The DSDM (Diaphragm Seismic Design Methodology) Consortium is conducting a research project on precast concrete diaphragms. Wood Structure Construction Methods: Gravity Design Guide for Reinforced Concrete Diaphragms A guide to assist design professionals in efficiently designing and detailing reinforced concrete diaphragms. Built in winter of 1903-1904, it withstood a major 7. For buildings with crosswalls in all levels: v u x D x Σ IKCSW d / [Σ(2 v u x D) + V c] where: Σ IKCSW d = total seismic forces of all diaphragms. design loads; therefore, induced unit shears and chord forces used in terms 1, 2, and 3 of the deflection equation are calculated using strength level design loads. 8. This seminar will introduce to attendees the alternative seismic design force level and the precast concrete design methodology, which are the subject of FEMA P-1051 Chapter 6. (3. Performance-based seismic design (PBSD) of high-rise buildings is a new methodology recently pioneered by MKA that is transforming the structural design of tall buildings in regions of high seismicity. g. The Simplified Analysis procedure is open to Seismic Design Categories B through F for Seismic Use Group I structures only. 06-03. Seismic performance-based design of flexible earth-retaining diaphragm walls Engineering Structures, 78(1), 57-68, DOI: 10. This continuous evolution requires that Caltrans periodically reviews and updates its seismic design methodology and criteria. c) Weak diaphragm design approach; d) Zones of inelastic deformations in diaphragms Current diaphragm design methods, e. The tables can be generated in metric or imperial units and the PDF output can be created in English or French. [6. Naito, Clay This paper presents an analytical study used to establish design factors for a new seismic design methodology for precast concrete floor diaphragms. 5: Sep-18: Rafael Sabelli, SE: Webinar: Seismic Design in Steel -- Concepts and Examples (Part 6): Building Analysis and Diaphragm Design (L2) 1. Methodology to Calculate Diaphragm Deflection Diaphragms are a component of wood-framed buildings that resist and transfer lateral forces produced by wind or earthquakes. Performance Based Seismic Design is the seismic design methodology of the future. 2. Instructional Material Complementing FEMA 451, Design Examples Timber Structures 13 - 22 Wood Structure LFRS Design Methods: Engineered • Partial reprint of engineered wood structural panel diaphragm info in 2003 IBC Table 2306. Edited By Peter Fajfar, Helmut Krawinkler. 2. Each of these research components focus on different but equally important levels of Common diaphragm analytical methods include Linear-Collector Diaphragm (LCD) and Distributed-Collector Diaphragm (DCD) analysis. The consortium’s research will integrate large-scale experiments at LU, finite element (FE) and nonlinear dynamic analyses at UA, and quasi-static and shaking table tests at UCSD. The DSDM Task Group will be led by Dr. The principal assumption is that the diaphragm stiffness is relatively high compared to the stiffness of supporting shear walls. This seminar also points out the many diaphragm design examples in FEMA P-1051 Chapter 11. 5: Sep-18: Rafael Sabelli, SE: Webinar: Seismic Design in Steel -- Concepts and Examples (Part 7): Design of the 08-07 Development and Design of Untopped Precast Concrete Diaphragm Systems for High Seismic Zones (Extension) Back to Top Charles Pankow Foundation, 1390 Chain Bridge Road, Suite 700, McLean, Virginia 22101-3904 (360) 326-3767 [email protected] 18-O- 2767 for existing buildings with soft, weak, or open front wall lines. Seismic Design Load : 20-6 The direct industry interaction with the academic researchers will occur through the Diaphragm Seismic Design Methodology (DSDM) Task Group comprised of a subset of the IAP (See attached list B). First Published 1997. 9 Design Methodology Pg. In a steel-framed structure, they are typically transmitted via horizontal members, such as beams, joists and trusses, serving as collectors. And finally, diaphragm design enables the engineer to pro-duce a building designed to resist high wind and seismic loads for little or no extra cost. The methodology is an iterative process that consists of nonlinear static and dynamic The design example presented from Volume 2 will explore methods to address the high diaphragm shears and the challenges associated with the potentially large deflections. The diaphragm was designed for a load of 37. Further FEMA P-1026 provided a new design philosophy for wood roof diaphragms that has been initially codified and is expected to appear in ASCE 7-22. Optimal PBSD methods provide different strategies to design the numerous variables, including strength, stiffness and ductility of each structural component. The knowledge required to create the design methodology was obtained through an integrated analytical and experimental research project using two Network for Earthquake Engineering Simulation (NEES) equipment sites. 2-3a, by 1. = . On-Demand Course: Seismic Design of Precast Concrete Diaphragms. Inertial forces are generated from the mass of the floor system under ground shaking. The Ψ factors are applied to the ASCE7‐05 diaphragm design forces to produce The DSDM Task Group is working with PCI on plans for disseminating the Methodology through PCI's Web site and technical literature, as well as working with agencies such as the American Society of Civil Engineers and American Concrete Institute to help develop national standards relating to seismic design and construction. 2 kN (Madsen et al. New design methods in ASCE 7, new findings in 3D models of buildings, and new experimental research are all shedding new light on the role of diaphragms in the seismic performance of steel buildings. Rigid diaphragm methods require extensive reanalysis for each rearrangement because the force distribution for the walls changes. Our expert staff draw on decades of experience to strategically plan, design and project manage seismic projects ensuring Terrex Seismic delivers on ALL of our clients seismic imaging objectives. This dissertation concluded by proposing a new rational seismic design approach for RWFD buildings based on the concept of distributed roof diaphragm yielding. A diaphragm that is designated as flexible is assumed to distribute the seismic forces based on tributary width or area while a rigid diaphragm is assumed to distribute Using these models, diaphragm seismic demands under expected hazard are evaluated through the nonlinear transient dynamic analyses (NLTDA). This research aims to extend the ductile end diaphragm concept used on steel bridges to make it applicable for bidirectional earthquake excitations, using unbonded braces as ductile fuses. design requirements for precast concrete diaphragms subject to earthquake loading. 2. 5 Comparison of the DSDM Design methodology with the Restrepo-Rodriquez These groups comprise the DSDM (Diaphragm Seismic Design Methodology) Consortium. This lack of 3- 134 2015 IBC SEAOC Structural/Seismic Design Manual, Vol. The project has been coined “DSDM” (Diaphragm Seismic Design Methodology). 2 Design Example 2 n Flexible Diaphragm Design The uniform loads W 1 and W 2 in the east-west direction are computed using the diaphragm lengths and wall heights. 95, are also used for comparison. This study highlights the importance of incorporating the diaphragm stiffness in design and the potential cost savings. 4 Seismic Design Procedure for Precast Concrete Diaphragms . 8 = Time effect factor. The Structural Engineers Terrex Seismic seeks out the latest technology to continually improve our service and your final product. Introduction conventionally reinforced or prestressed. Acknowledging this fact, there are efforts in the literature lately to directly relate the appropriate selection of an “ effective ” seismic coefficient khE (for C. Kementerian Pekerjaan Umum dan Perumahan Rakyat. The purpose of this chapter is to present criteria and example problems of the current state of practice of seismic design of wood and reinforced masonry buildings. This difference in effort has led some practitioners to ad-vocate flexible diaphragm design as the building code–approved standard in all cases (Qazi 1999). Add to My List Edit this Entry Rate it: (1. C. Six story main lobby Old Faithful Inn, Yellowstone, undergoing renovation work in 2005. He has been involved with code changes to the Uniform Building Code and IBC for over 25 years and is a voting member of the American develop a diaphragm seismic design methodology (DSDM) for precast concrete buildings. , this framework results in two major advancements: the accurate computation of various severe damage and failure modes of RCSWs and building systems that consider the nonlinear behavior of all structural components. Examples of Seismic Use Group I structures are apartment complexes, condominiums, hotels (without large meeting areas), parking facilities, medium sized office buildings, etc. The traditional diaphragm design method has always been thought to be a conservative design method, especially when applied to large diaphragms. Identify effects of structural characteristics on seismic design/performance : 3. 9 Diaphragm Seismic Design Methodology (DSDM) . Collectors, also known as drag members, transfer the diaphragm shear to shear walls and other vertical elements of the seismic force resisting system. Insights into bridge behavior and methods for improving their performance are constantly being developed. Currently Auto Diaphragm is in use by some of the largest consulting firms in the world as the preferred diaphragm analysis tool for seismic design of floor diaphragms. The Ψ factors are applied to the make up Caltrans’ seismic design methodology. It should be noted that the flexible diaphragm presented in the example is a conservative approach as it assumes two simple spans. The diaphragm is assumed to be flexible, but the assumption will be verified. • Selection of Analysis Method • Relative Storey Drift Check • Second-Order Requirements Check • Seismic Overturning Check • Strong Column – Weak Beam Check • Joint Shear Check • Ductile Member Design and Detailing • Diaphragm Models and Storey MEshing • Shearwall Modelling and Basement Walls • Wall Coupling Beams A new seismic design methodology has been developed for precast concrete diaphragms. How bridges respond during earthquakes is complex. A new seismic design methodology is proposed for precast concrete diaphragms [1, 2]. Roof dead load = 14 psf Walld ead load =p cf psf 72 5 12 150 90 6. Diaphragms act as horizontal “beams” between the vertical elements (walls and/or columns) that resist the lateral forces during an earthquake. the light-frame design examples in the Seismic Design Manuals, the Guide to the Design of Diaphragms, Chords and Collectors, and Four-story/Five-story Wood-frame Structure over Podium Slab. The retrofit methodology contemplates various steps that go from assessment of the wall-diaphragm connection to the actual design of the retrofit solu-tion (NZSEE 2006, ASCE/SEI-41 2014, Paganoni & D’Ayala 2014). The report provides the background research performed by Professor Schafer and by NBM Technologies to develop seismic provisions for improved performance of bare steel deck Auto Diaphragm. 9z S (1 – 1/n) 2 where zS = modal contribution coefficient modifier dependent on seismic force-resisting system. 027, 2014 Francesco Cavalieri SEISMIC DESIGN CATEGORY: A classification assigned to a structure based on its Occupancy Category and the severity of the design earthquake ground motion at the site as defined in Section 11. 06. 2 Design Methods Engineered design of wood structures to resist wind and seismic forces shall be by one of the methods de-scribed in 2. The diaphragms were designed and detailed according to a new design methodology developed as part of parallel research. Diaphragm Design As noted, diaphragms are designed in accordance with simple beam equations. The three-story, half-scale test structure was designed to be diaphragm sensitive in flexure with a floor aspect ratio of 3. Current code-based consideration of seismic P-Δ effects is generally based on simplistic elastic models, and despite major advances in seismic systems and analysis techniques, no simple and reliable design methods for seismic stability are available. 10-1) The diaphragm design force shall not be less than: Fpx 0. B = δ max / δ avg δ calculated for static loads applied at ±0. Findings resulted in the adoption of a revised force demand and resistance methodology for precast concrete diaphragms in 2015 NEHRP and ASCE/SEI 7-16. The objective of this guide is to provide comprehensive information on the design and detailing of reinforced concrete columns in buildings assigned to any Seismic Design Category. Diaphragms for seismic loading — Part 2 DIAPHRAGM DESIGN In seismic design of buildings, diaphragms transfer in-plane forces, comprising of inertial forces and transfer forces to vertical members of seismic forces-resisting system. An active panel Diaphragm Design Γm1 = 1 + 0. One consequence of this method is that the result is independent of wall location and “Any system of method of construction to be used shall be based on a rational analysis in accordance with well established principles of mechanics. 7 Testing Photos Pg. First phase falls into inspection and diagnose of the wall-diaphragm connection, charac- SDII investigator Ben Schafer released a report: “ Research on the Seismic Performance of Rigid Wall Flexible Diaphragm Buildings with Bare Steel Deck Diaphragms ” in the DSpace collection of CFSRC in support of proposed new provisions for seismic design of “Big box” buildings with bare steel deck roofs. However, many of the concepts that are presented here apply equally to other diaphragm types. (b) Any building with a height greater than five metres. This is because the maximum diaphragm forces may occur at a different point during the earthquake than the maximum seismic base shear. The DSDM Consortium research closely integrates finite element analyses of the diaphragm at UA with full-scale reinforcing detail experiments at LU and shaking table system tests at UCSD. The program will automatically calculate the center of mass and the 5% accidental eccentricity for the various seismic load cases. Traditional Diaphragm Design. 1. G. Panel diaphragm design has been proven through some of the most harrowing hurricane and earthquake experiences imaginable. Findings resulted in the adoption of a revised force demand and resistance methodology for precast concrete diaphragms in 2015 NEHRP and ASCE/SEI 7-16. g. REU Program; News; Contact; Links Nakashima, M. Floor diaphragms on transfer levels of tall buildings typically experience significant shear and flexural demands and complex local behavior as they are used to re-distribute large seismic forces among vertical lateral force resisting structural elements. 4. Modify F px to develop defined yielding under: – Design Basis Earthquake – Max Considered Earthquake 2. Holombo has over 30 years of bridge engineering experience in California. SD1 = 5% damped design spectral response acceleration at 1 second period SD1 = 2/3 (S M1) = 2/3 (Fv S 1) Note: If S 1 ≥ 0. Methods and details of seismic retrofitting of bridge abutments are discussed. A Design Example of a Wood Cantilever Diaphragm Designers of modern low-rise and mid-rise multi-family buildings often face challenges due to fewer opportunities for shear walls at exterior wall lines (e. In addition to the torsion dunatural eccentricity,e to NBCC requires that a minimum e. The ASCE/SEI 7-16 recently introduced an alternative methodology to determine diaphragm design forces that considered various diaphragm systems. Also note that this is in the chapter on seismic design requirements; in Chapter 26 for wind loads, Section 26. 2. These factors, established through extensive parametric studies, align diaphragm design strengths with different seismic performance targets. Creator . The general distributions of the forces which develop within the floor diaphragm were also investigated. ground motion, extreme wind). 59 RP3-4. A floor plate is an example of a horizontal diaphragm, and in many designs, a diaphragm will also serve as the building’s floor or roof element. D. Development of a Seismic Design Methodology for Precast Diaphragms - PHASE 1 SUMMARY REPORT. nus standard is meant to replace the design procedure for precast concrete diaphragms for struc­ tures assigned to Seismic Design Category (SDC) C, D, E, or F that was developed and accepted for use by ASCE/SEI 7-16 in Section 14. D. Demystifying Diaphragm Design 4 COURSE DESCRIPTION The 2018 International Building Code (IBC) specifies that structures using wood-framed shear walls and diaphragms to resist wind, seismic and other lateral loads shall be designed and constructed in accordance with AWC’s 2015 Special Design Provisions for Wind and Seismic (SDPWS)or2018 Wood Frame Abstract. These forces are different than diaphragm design forces. N = Resistance factor. The software has been designed to automatically generate strut and tie grillage within ETABS platform for seismic analysis of floor diaphragms. , Huang, T. The document is the outcome of the revision of the earlier version of NBC 105: 1994 Seismic Design of Buildings in Nepal. While 4. 3. The AASHTO Guide Specifications for LRFD Seismic Bridge Design (2011) already include provisions for the design of steel Seismic forces in a building structure must be transmitted from the roof and floor diaphragms to the vertical seismic force-resting system (and the foundations). Design Framework The DSDM Consortium has endorsed the development of a seismic design methodology for precast concrete dia-phragms based on performance requirements and incorporat-ing capacity design concepts. Sketch the flow of forces through the D-region Calculate Strut and Tie Forces Select steel for Ties and Determine its Location. Σ (2 v u The research behind Diaphragm Seismic Design Methodology (DSDM) integrates finite element analyses of a diaphragm with full-scale reinforcing detail experiments and shaking table system tests. McCabe: This letter is to confirm the participation of the Precast/Prestressed Concrete Institute (PCI) in the joint research initiative “Development of a Seismic Design Methodology for Precast Diaphragms” with a university consortium comprised of the University of Arizona (UA effects. Diaphragm Design Force, Fpx Strength Design force level Floor and roof diaphragms shall be designed to resist design seismic forces from the structural analysis, but shall not be less than that determined in accordance with the following: px n i x i n i x i px w w F F ASCE 7 (12. structures is essential for seismic and wind design. So, the imposed forces do not go beyond A bidirectional ductile end diaphragm concept was proposed to implement ductile end diaphragms in straight or skew bridge superstructures, to resist bidirectional earthquake excitations. A one-way span direction is applied to the diaphragm floor panels and surface panels (representing wall/cladding) on the ‘front’ and ‘back’ Y-elevations. The structure was subjected to a series of 16 strong ground motions with increasing intensity including design-basis and maximum considered earthquakes for which the diaphragms were designed. Edition 1st Edition. 7 Instructor: Dr. The design spec-tral response acceleration parameter in the short-period range, In unblocked diaphragms, the bending moments andshear are both resisted by the sheathing. The general distributions of the forces which develop within the floor diaphragm were also investigated. The purpose of this paper is to outline the foundation for the research by presenting the underlying design philosophy and resulting design framework that will serve as the basis for the technical papers to follow and the eventual design methodology at the projected RP3-4. SUBJECT: Precast Concrete Diaphragm Research Program Dear Dr. The 2015 guideline document Seismic Design of Rigid Wall-Flexible Diaphragm Buildings (FEMA P-1026) introduced a new seismic design methodology that specifically recognized the dynami c response of this building type as a function of inelastic behavior in the diaphragm, where current design procedures address dynamic response The magnitudes of seismic forces which develop in floor diaphragms were investigated in this report to enable the development of a desktop floor diaphragm force design method for use in a structural design office. 1 Introduction Pg. design and construction of wood members, fasteners, and assemblies to resist wind and seismic forces. To This webinar presents methods on how to determine the required thickness of a diaphragm based on serviceability and strength (in-plane and out-of-plane) requirements. In structural engineering, a diaphragm is a structural system used to transfer lateral loads to shear walls or frames primarily through in-plane shear stress. 5 earthquake in 1959. The SDII team released a report: “ Development of Steel Deck Diaphragm Seismic Design Provisions for ASCE 41/AISC 342 ” in the DSpace collection of CFSRC in support of proposed new provisions for seismic repair and rehabilitation of steel deck diaphragms; both bare steel deck and steel deck with concrete fill. 4. As Seismic Design Category A is exempt from seismic design, it is not specifically addressed, although many of the diaphragm analysis and design methods described herein are applicable to the design of diaphragms to resist wind Diaphragm Design Disussion Among other factors, the ability of a postframe building to withstand high winds loads or high seismic loads requires that the structure have adequate diaphragm stiffness in the roof and in the walls. The overall goal of this study is to The diaphragms were designed and detailed according to a new design methodology developed as part of parallel research. In ASCE 7 building design terms “force-controlled” is similar to R=1, or design without force reductions. In particular, the design procedure known as the Direct Displacement Based Design (DDBD) method, which has been developed in structural engineering over the past ten Compared with analysis methods used in current performance-based seismic design (PBSD) and retrofit practice in U. For precast concrete diaphragms, extensive research has been done and performance-based seismic design methodologies have been proposed , , , . Recent research has identified that code level seismic demands in ASCE 7-10 used for diaphragm design are considerably lower than demands in real structures during a seismic event. 2014. Then k 2 can be found using k 1 and the diaphragm dimensions. The procedure in ASCE 7-10 begins by determining forces using the equivalent lateral force method. The structure was subjected to a series of 16 strong ground motions with increasing intensity including design-basis and maximum considered earthquakes for which the diaphragms were designed. Seismic performance assessment or seismic structural analysis is a powerful tool of earthquake engineering which utilizes detailed modelling of the structure together with methods of structural analysis to gain a better understanding of seismic performance of building and non-building structures. For Performance Based Seismic Design (PBSD), it is important that rational procedures are used to estimate diaphragm demands and a comprehensive approach is used for the design of diaphragm components (i. The paper presents the seismic vulnerability assessment and the subsequent retrofitting strategies of a reinforced concrete (RC) strategic building in… This paper presents an analytical study used to establish design factors for a new seismic design methodology for precast concrete floor diaphragms. It is assumed that Seismic load can only be applied at diaphragm/floor levels. Mr. diaphragms and vertical diaphragms (shear walls), are designed for lateral forces using ASD; while masonry shear walls are designed for lateral forces using LRFD. The project aims at developing an industry-endorsed comprehensive seismic A new seismic diaphragm design methodology has been developed for precast concrete floor diaphragms. This method makes all the non-resilient deformations occur only in parts which have the ability to sustain the whole seismic energy. This discussion paper presents a suggested method for determining the design diaphragm actions at a given floor level, how to proportion their transfer into the seismic resisting systems and how to design and detail the supporting beams/composite metal deck for these actions. San Luis Obispo, MSc Thesis , “ An Investigation of influence of diaphragm flexibility on building design through comparison of forced vibration testing and Design Loads and Associated Criteria for Buildings and Other Structures (ASCE 2016). 2. Report Number . INTRODUCTION (time out of service), resulting from damage. , diaphragm supported by shear walls at each side), the designer uses the following equation to calculate the unit shear force to be resisted by the diaphragm sheathing: an earlier researcher to denote structures. The methodology will aim to satisfy design requirements at the three “resolution levels” ing a comprehensive seismic design methodology for precast/ prestressed concrete floor diaphragms. The Seismic Weight of each diaphragm is the total tributary weight associated with it depending on the Load Combination chosen for calculating these forces on the Seismic Loads dialog box. As adopted by California Building Code (CBC), Section 2205A. S. Earthquake Retrofit Guidelines for Bridges : 20-5 . The strength design methods use load factors which are derived based upon a statistical evaluation of the probability of the various load occurrences and are quite similar to those used in the AISC LRFD provisions. . SEISMIC FORCE-RESISTING SYSTEM: That part of the structural system that has been considered in the design to provide the required resistance to the diaphragm, as well as dimensional requirements for the pile cap. Nepal National Building Code NBC 105: Seismic Design of Buildings in Nepal is the title of this document. 8ND = Factored resistance. 4) A seismic design strategy that relies on ductile end-diaphragms inserted in the steel super-structure can be, in some instances, an effective alternative to energy dissipation in the sub-structure. 10-2) The diaphragm • 2008 SDPWS-”Special Design Provisions for Wind and Seismic” Analysis and Design references: • The Analysis of Irregular Shaped Structures: Diaphragms and Shear Walls-Malone, Rice • Woodworks-The Analysis of Irregular Shaped Diaphragms • Design of Wood Structures- Breyer, Fridley, Pollock, Cobeen • SEAOC Seismic Design Manual to Seismic Design Categories D, E, or F. 1. the Steel Deck Institute (SDI) [3,4] and the Stressed Skin [5] design approaches, were formulated mainly from the results of monotonic testing of single sheet length bare steel roof On the development of seismic design forces for flexible floor diaphragms in reinforced concrete wall buildings Diaphragm Seismic Design Methodology. In the 2014 edition of ACI 318, a new chapter devoted to the design and detailing of reinforced concrete diaphragms was includ-ed for the first time. e. 2 Performance-Based Design Methodology The first step in PBD is to establish performance objectives described as the combination of an expected performance level with expected levels of hazard (e. 11 External Stability Pg. The research team is comprised of members from the Uni-versity of Arizona (UA), the University of California San Diego (UCSD), and Lehigh University (LU). 2. General Principles and Calculation Methods (Obras de Hormigón Armado. Pelatihan. The DSDM project is a collaboration of the University of Arizona (UA), UCSD, LU, and the Precast/Prestressed Concrete Institute (PCI). 3 Code Procedure for Simplified Analysis Method. ASCE 7-16 (ASCE 2016), two different design methodologies exist for the seismic design of diaphragms. The method incorporates nonlinear behavior of concrete and accounts for actual lateral force distribution which enhances performance of building in given Seismic hazard. 1016/j. The design factors include diaphragm force amplification factors Ψ and diaphragm shear overstrength factors Ω v. Wall and Diaphragm Design Ricky McLain, MS, PE, SE Calculate wind pressure using Directional Method (ASCE 7 Chpt27) p = q h Seismic Design of Wood Light-Frame Title . Seismic design of new bridges and assessment of existing bridges in Oregon needs to consider two-levels of performance criteria; life-safety and operational. Roof height = 21 feet average Parapet height = 2 feet average. 2 provides requirements specific to wood diaphragms in open front structures, these are in addition to and not a replacement of seismic design criteria of ASCE 7 (Figure 4). The design requirements for concrete diaphragms are contained size, shape, diaphragm material, and diaphragm connections. While computing the seismic weight at a particular diaphragm, the self weight of the members/columns and plates between any two diaphragms is equally Continuing Education Credits Available – 1. Seismic design factors were used to be applied on top of diaphragm seismic design forces in the current code. 1 Load Combinations including Orthogonal Seismic Load Effects. 2SDS Iewpx minimum ASCE 7 (12. 1. Seismic Testing For Allan Block and Huesker Synthetic Table of Contents Columbia University Pg. 10 D n Plan • Dynamic analysis is a useful tool for seismic design if used correctly • Even ELF design method can use a dynamic analysis to troubleshoot models • Use engineering judgement, calibrate yourself • Know what you want to get from your analysis • Consider level of analysis required based on 1 Diaphragm segment plan. Exception: Wood structures shall be permit-ted to be constructed in accordance with pre- Concrete Diaphragm in-plane Shear Design Based on ACI 318-19: 24: SMRF - ACI: Seismic Design for Special Moment Resisting Frame Based on ACI 318-19: 25: Special Shear Wall - IBC: Special Reinforced Concrete Shear Wall Design Based on ACI 318-19 & 2018 IBC: 26: Suspended Anchorage: Suspended Anchorage to Concrete Based on 2018 IBC & 2019 CBC: 27 The purpose of these Seismic Design Guidelines is to provide additional information and clarification to Civil or Structural engineers in order to comply with Ordinance No. Widening Existing Bridges : 20-1 . 5 addresses requirements for diaphragms of this type. diaphragm seismic design methodology