Equivalent lateral force method example

  • The lateral force induced at each level thus can be computed as shown in Table 1 using Eq. Lateral Load Distribution of Frame Building. The base shear percentage has been determined above to be 3. truss system of concentric/eccentric type, lateral forces resisted thru axial stresses in members. Example In a similar way, proceed from the top to bottom, analyzing each of the small pieces. 2 Factors That Increase Lateral Force (1) Mechanism of generation of lateral force by the wheelset Fig. 6m above the ground and at distance b = 1. The analysis is carried out as per IS 1893- 2002 (Part 1) A step by step procedure for analysis of the frame by equivalent static lateral force method is as follows: Step 1: Calculation of lumped masses to various floor levels. forces. However, a great deal of resistance is provided by the basic configuration of the structural system of a building. Also tested this with other load cases in the model i. Jonathan M. The user is able to select from several methods for the calculation of equivalent lateral forces. Select a desired yield mechanism and target drift for the structure consistent Example 1: Analysis of the offshore pile group shown in Fig. Wood structural panel walls for structures three stories or less 5. Rigid diaphragm shall be a structural slab or equivalent with capacity to resist deflection of the top of the wall. The idea of equivalent lateral force method is to distribute part of the seismic force (base shear) to every floor, which are able to transfer lateral loads. 8 or Equation 12. Total base shear is the summation of the equal shears applied to each floor . Are you an ASCE Member? We recommend that you register using the same email address you use to maintain your ASCE Member account. Lin in June 1963. If the building structure has shear walls,  23 Jul 2013 Equivalent Lateral Force Analysis (Static Analysis), Seismic Analysis Using UBC And IBC Codes,Equivalent Lateral Force Analysis in STAAD Pro v8i. • Example 13. This occurs when a relatively large axial force and a small moment are applied. This means horizontal displacement at all joints located at the beam level s same. For example, if a penthouse is included in a building model, the . -can use 1 diagonal compression member in each bay OR 2 tension diagonals. EERI, Andrew S. Modal Response  22 Jul 2015 Examples that illustrate the difference and the limitations of the two The Equivalent Lateral Load method is essentially a simplified static  Equivalent static force analysis. Accordingly, more advanced methods of analysis are required for design of these structures. Following are the steps of the simplified procedure: 1. CONTRACT OR GRANT NO. •The weights of the structure, when accelerated along the direction of the earthquake, induce forces in the building. . 3 EQUIVALENT LATERAL FORCE PROCEDURE . Friction angle of soil: = 30 degree. 3. Topics: Detailed Example Structure Description; Implementation of the Equivalent Lateral Force method for Case Study Find the reactions at the base of the columns using the portal method of analysis. Method for Determining Equivalent Lateral Seismic Force One of the analytical procedures permitted in ASCE 7 for calculating seismic loads is the equivalent lateral force procedure. e. lateral force. 4—Equivalent Lateral Force Procedure for Seismic Design of Buildings The International Code Council’s 2003 International Building Code (IBC) Section 1617. The seventh step is to determine the seismic lateral load, F x, for each level of the structure from Equation 12. The Detailed Analysis Method In the detailed analysis method, the piles were modeled as frame elements connected to lateral nonlinear springs spaced at 0. Note that k =1 (k is a distribution exponent related to the frame period) has been assumed in Eq. Table 1. Equivalent Lateral Force Method work provided on Autodesk Knowledge Network is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3. Step 1: Pavement Design (with examples) | Complete Data. EXAMPLE CALCULATION – Seismic Actions to BC3: 2013. 5m from the centerline of the pole. The basic concept of load-balancing is also a representation of the influence of tendons by using equivalent loads. The total force P per unit length of wall will be equal to the area of the pressure diagram. (3) It is worth noting that by equalising the unit shear force and the stress, which is incorrect from a solid A. Re: Equivalent Lateral Force Method, according to: EN 1998-1:2004 Sequel to previous post, is a comparison of calculated Sd(T1) value for period T1 (for ag = 1, S = 1). C FRAME BUILDING (IT OFFICE, ALMORA) IN SAP 2000 V14 5. Static methods employ the use of pseudo-lateral forces, similar to the Equivalent Lateral Force method in ASCE/SEI 7 -10, as well as pushover analysis for the nonlinear static procedure. the equivalent static lateral force method, in which a seismic coefficient is applied to the mass of the structure, to produce the lateral force that is approximately equivalent in effect to the dynamic loading of the expected earthquake. 1 Section force-deformation response & Plastic Moment (Mp) • A beam is a structural member that is subjected primarily to transverse loads and negligible axial loads. 4. 5 expression (3. (4) as mentioned early in this paper. When designing the frame, and specifically the forces on the bracing system, it is much easier to consider the net equivalent force at each floor level. Material (stress -strain) relationships are needed only to calculate deflections. 1. That angle of attack increases as the curve radius decreases. 2L = 5 ft from each support. In this article, we introduce a complete lateral force calibration procedure that employs the torsional Sader method and does not require making contact between the tip and any sample. Assume the total design lateral force V = 100 kN. All other light-framed walls 4. Equivalent static lateral force analysis is based on the following assumptions, 1) Assume that structure is rigid. Note that at this time liquefaction has already triggered (ru=100%), and the lateral spreading load has almost fully mobilized. 0196 ˛ w = 3 degrees Find Forces acting on the wall (both horizontal and vertical) Example of Equivalent Fluid Compute Equivalent Fluid Unit Weights (Active Case) G h v K a cos w G h v 120 0. 2 – Combustion turbine building. If any mistakes are found they will be added to the Addendum portion you will find under each spreadsheet. The Equivalent Lateral Force Procedure as contained in ASCE 7 Standard specifies a seismic base shear force V as: V= C s W (2. Solution: 2 U 2 = =− T Integrating =− T2 2 + 1 (1) Integrating U=− 3 6 ¾ 𝐼 + 1 T+ 2 (2) The net force in the lateral direction is zero since the forces on the side walls will cancel each other. The response spectrum method of analysis is developed using the following steps. The second example is a five-story masonry hotel using the Equivalent Force Procedure of Section 12. 3465 K P = 4. Seismic Design (Equivalent Lateral Force) Spreadsheet (v1. Create a new account. Requirement: Using Rankine's lateral earth pressure The line of action of this force is at height h = 6. The example uses water in system of standard weight carbon steel pipe. . Thus the design base shear is (3. PERFORMING ORGANIZATION CODE 7. The results of the proposed method are in harmony with the solution of the improved portal method. 5 s or less, k = 1; for structures with a period of 2. Equivalent lateral force method (Static method)- IBC2009. 5 to 4. Chrysostomouf) Equivalent lateral force and modal analysis procedures for yielding build- The equivalent lateral force procedure as contained. Bearing wall system 1. Figure 1: Typical transverse bent. The total design lateral force or design seismic base shear (V b) along  Equivalent Lateral Load Method vs. Lateral Example 1 – Calculation of Design Seismic Force by Static Analysis. An outline of the step-by-step, Performance-Based Plastic Design (PBPD) procedure follows, with detailsto bediscussed in subsequent sectionsin this chapterand theoret-ical justification given in the Appendix. 0, SD1⫽0. 5 feet (2. Setting of ELF is very simple - it is just an extension of a seismic load case. Equivalent length for fittings should be included but have typically been ignored. Irregularity (5a) exists if the lateral strength of any story is less than 80% of the strength of the story above. Calculation of the Equivalent Lateral Forces. Wacker, David G. jonathan m. Simple relationships for the idealized yielding system have been established by others but are repeated below to aid in the presentations of the fol- SIMPLIFIED ANALYSIS PROCEDURES FOR BUILDINGS WITH DAMPING SYSTEMS 963 Figure 1. 0 Unported The equivalent lateral force method treats the seismic loads as equivalent lateral loads acting on various levels of the building. Fig. THEORY and METHOD The effects of the relative stiffness of the upper stories and the establishment of soft stories in the underneath of the structure may be causes to analysis and design the pyramid structures as irregular rules according to authenticable standards. For example, in a propped overhanging building (Figure 2. Lateral Earth Pressures A flexible wall system design is required to resist the anticipated lateral pressures without undergoing significant or excessive lateral deflections. 6 and Ts⫽0. 78 Equivalent Elastic Modeling for the Direct-Displacement-Based Seismic Design of Wood Structures. 2. direct axial forces are large, each plate (for example, flange or web plate) may buckle locally in a plane perpendicular to its plane. 13 2009 . Answer Wiki. First, the total seismic force (base shear) is calculated. 05 to 0. (4). Correctly apply lateral forces to structures with rigid and semirigid Calculate the base shear and story forces using the Equivalent Lateral Force Method. J. • It is the ratio of the difference in deflection between two adjacent floors divided by the height of the story that separates the floors. Table 2. Light-framed walls with shear panels a. displacement curve for a linear elastic structure. Taking 0∑Fx = : NF F F= cc sc st+− Moment equilibrium: ' sc st22 hh MF d Fd ⎛⎞⎛ ⎞ =−− −⎜⎟⎜ ⎟ ⎝⎠⎝ ⎠ εcu εscs Instructional Material Complementing FEMA P-751, Design Examples. EERI, and Christis Z. 5, where V n is the smallest nominal shear strength from MSJC Code Section 3. A lateral force will be generated at the road when the bike tips to one side. 2 Solution. ChapTER 4 Lateral vi List of Tables Table 1 Calibrated connector parameters 13 Table 2 Example CLT wall design resistance (kips) 15-16 Table 3 Test matrix for 7. Earth Pressure and Retaining Wall Basics for Non-Geotechnical Engineers Richard P. Example Calculation of Pressure Loss using Equivalent Lengths. For each free body the stresses are determined in each fastener. Determine the magnitude and location of FR exerting on the section BC Consider the equilibrium situation shown, Step 1. Also, if a new version is uploaded the version will change • The force (flexibility) method expresses the relationships between displacements and forces that exist in a structure. It allows a clear understanding of the contributions of different modes of vibration. A Poisson's ratio of 0. The analysis was run first with P-delta included, and then again without P-delta. Seismic mass of each moment-resisting frame: Roof: = 2283/2/32. Base shear is an estimate of the maximum expected lateral force on the base of . 52 pcf G K a sin w G Seismic Design (Equivalent Lateral Force) Spreadsheet (v1. The equivalence is restricted to a single mode of vibration. SYSTEM2 LATERAL-FORCE-RESISTING SYSTEM DESCRIPTION R o HEIGHT LIMIT FOR SEISMIC ZONES 3 AND 4 (ft) 304. eberhard 9. The translational stresses, f vx and f vy, are easily found by dividing the respective applied translational forces by the sum of the bolt cross sectional areas. P. Page 11 of 22 The distribution of lateral forces is computed in Figure 7. (1996). The Base Shear Multiplier is used in the calculation of the ELF Limit. Whittaker,c) M. 5 2. For structures with a period of 0. Some of these factors are dynamical characteristics of structure such as periodicity, depreciation, mode form and structure capacity to adopt plastic transformation. static and the dynamic analyses are comparable, there is  Seismic analysis is a subset of structural analysis and is the calculation of the response of a The earliest provisions for seismic resistance were the requirement to design for a lateral force equal to a proportion of the building weight (applied at Structural analysis methods can be divided into the following five categories. Preliminary design of BRBF system Use of equivalent force method This preliminary design guide presents an example for design of a steel structure with Buckling Restrained Braced Frame internal axial loads are defined from linear static analysis of the earthquake load case. Instructional Material Complementing FEMA 451, Design Examples Seismic Load Analysis 9 - 21. Height of earth at toe. always give a positive lateral pressure. As a result of this method, the static forces are generated and applied to rigid (or semi-rigid) diaphragms or vertical elements (columns, wall), which can carry calculated forces. mechanisms [4]. 12. Ramirez,a) Michael C. Calculation of Design Seismic Force by Static Analysis Method 4 2. Vertical Structural Irregularities. That means if your induced lateral pressure at one third embedment (S1) exceeds this value, the you are compelled to find new alternate approach. 1 Introduction: Apart from gravity loads, the structure will experience dominant lateral forces of considerable magnitude during earthquake shaking. Federal Way, WA, USA ABSTRACT: Analysis of wharves/piers under lateral loads is often conducted by assuming the piles to be fully restrained at a presumed distance below the mudline. The same procedure is applied for each direction (X,Y,Z). If it is a non-yielding wall (restrained) the added lateral force per square foot is computed using F w = k h (density)(retained height), in psf. In this case the equivalent rectangular stress block is outside the section and so all of the section is in compression. Equivalent Lateral Force (ELF) Analysis & Response Spectrum Analysis are types of linear elastic analysis but the difference is, one is static analysis while the other is dynamic analysis. Moving on, the video shows how to find different parameters and factors that are required to give input in the formula of equivalent static design force at each level of the given structure. - Shafts are treated as beams when analyzed for lateral deflection. a). 1 Equivalent Lateral Force Method . The relative displacement between soil and pile is 0. This paper focuses on finding a suitable lateral load distribution for the design of SPSWs, considering their inelastic behavior. 5 seconds This paper concentrates on the prediction of these two quantities by the equivalent lateral force (ELF) procedure of ASCE (which is virtually identical to that described for bridges in AASHTO and EN ). The wind force acting on the sign is statically equivalent to a lateral force W and a torque Τacting on the pole. Lateral Force Earthquake Engineer Seismic Zone Torsional Moment Story Drift These keywords were added by machine and not by the authors. Seismic Analysis. Design of Beams – Flexure and Shear 2. Different programs use different methods to calculate M cr, F Total lateral seismic force of a wharf segment at displacement demand H The distance between the center of pile top plastic hinge and the center of pile in-ground plastic hinge – Monotonic lateral load pattern slowly increased until lateral capacity of the structure is reached – Seismic code equivalent static or first mode loading pattern often used – Capacity of the structure depends on loading pattern . 5 inches in a gust of 70mph winds. Y. The idea of equivalent lateral force method is to distribute part of the seismic force (base shear) to every floor, which are able to transfer lateral loads. Transforms the soil acting on the retaining wall into an equivalent fluid Example of Equivalent Fluid Method Given Wall as shown above K A = 0. 6. are a function of various parameters, for example, zone factor (Z) and the soil   Different design standards recommend different values for k; for example, 1 in the . Method for Determining Equivalent Lateral Seismic. Apply the Equivalent Lateral Force method of analysis to determine seismic demands on building structures as a final design or as a preliminary design for more rigorous analysis methods. stanton, marc o. In our example: So with a 24-degree banking, 1. 0 – The total force in each case is assumed to act at one-third the height of the triangular pressure distribution, as shown in Figure 3. Location of Centre of Stiffness 11 5. 7%. The roots can be determined through a combination of graphing and numerical methods. ASCE 7 6. and strain-softening effects. For instance a retaining wall can be used to retain fill along a slope or it can be used to Re: Equivalent Lateral Force Method, according to: EN 1998-1:2004 Sequel to previous post, is a comparison of calculated Sd(T1) value for period T1 (for ag = 1, S = 1). Shear Walls 9 Example: Flanged Shear Wall m m n v v m m in E in E in E in in A E Ph E I Ph P P k 0. With LFM, we determined the torsional spring constant of a CO-terminated tip molecule to be 0. 7. In order to prevent this undesirable phenomenon, the width-to-thickness ratios of the thin flange and the web plates are limited by the code. READ ALSO: 2 Methods on How to Scale Base Shear in ETABS  12 Nov 2016 7 Equivalent lateral shear force along two orthogonal axis (Source: . 1 – 3 AFM force measurements may be divided into normal force and lateral force measurements. Method. 28 Nov 2018 The dual equivalent lateral force (DELF) method is presented that permits the extension of the ELF method by separating the hybrid structure  4) Qualitatively describe the equivalent lateral force method and identify when it is appropriate to use as a few examples are illustrated below in Figures 1-4. Deflection Due to Bending. Area Moment 2. This is a simplified procedure that can be used for seismic analysis on residential decks be-cause residential structures are built with light-frame construction. A seismic load generated in accordance with the Response Spectrum Procedure should not be greater than a load calculated using the simplified method (Equivalent Lateral Force) as a base shear force. performing organization code 7. Equivalent lateral force method: At first we will know the application and feasibility of this method, later we will know how it determines earthquake loads. 5 means that there is no volumetric change principles of pile capacity calculations presented in Eurocode 7 and other methods with adequate explanations. 66 m) and if your required embedment depth exceeds 12 ft, you are required to find another analysis method. Basic & Appl. seismic coefficient method and response spectrum method. , Canada August 1-6, 2004 Paper No. 1. ies in which the magnitude and distribution of lateral pressures on a retaining wall caused by the application of a concentrated load on the surface of the backfill were meas­ ured. 10), the   illustrate a method and example calculation for determin- gions in the US. 3 m) long and 7. So the weights on each floor will be divided into two to calculate the lateral forces on each moment-resisting frames. Also, if a new version is uploaded the version will change Introduction the lateral force method versus modal response spectrum analysis In the lateral force method a linear static analysis of the structure is performed under a set of lateral forces applied separately in two orthogonal horizontal directions, X and Y. Total number of degree of freedom is 3Nj where Nj is the number of joints in the frame. 10-1 gives the diaphragm design forces as a function of story shear in the Figure 1: Plan and elevation of example building. w P V(x) M(x) x w P V(x) Part B: Seismic force analysis (ASCE 7-02) Two steel frames on the perimeter are moment-resistance frame. This section compares the ELF (Equivalent Lateral Force) Limit, as reduced by the Base Shear Multiplier, and the I/R Limit. The lateral seismic force is equal to vertical distribution factor, C vx, times the total design lateral force or base shear. The deformation can be measured, and the force can be deduced. Design forces in the equivalent strut are then calculated based on elastic shortening of the compression-only strut within the braced frame. In this case, the method of equivalent nodal forces gives the exact solution for the displacements and rotations. method of each code, the authors computed the horizontal seismic forces of a The horizontal seismic action can be converted to the equivalent lateral . Wind in the E/W Direction Figure 7. 1 – Combustion turbine building. Basis of Equivalent Lateral Force (Static Force) Procedure VB = m a VB = (W/g) a VB = W (a/g) VB = W Ah Ah = Basic horizontal seismic coefficient VB = Base shear W = Total weight of the structure a = Acceleration induced at the base during earthquake g = Acceleration due to gravity of lateral stiffness and afterward the conclusion of this study describe. 5 s or more, k superstructure inertia is 75% of its maximum and the lateral spreading force (crust load) is 70% of its maximum. 2 using the traditional statical method Approach I. I tried to disregard the self-weight density for the elements in (basement & penthouse level) by dividing the self-weight case into two parts (self-weight-seismic & self-weight-non seismic) then I used (factor = 0. Equivalent lateral force analysis procedure is by far the simplest method to use, and is still used in most “regular” buildings and medical facilities. 8 Building Height hn = 270 ft Problem statement Effective Seismic Weight W = 58,500 kip Calculation of Seismic Response 12. They are included in the example problem with equivalent lengths found in Table A-3. Drift Story • It is a measure of how much one floor or roof level displaces under the lateral force relative to the floor level immediately below. , Equivalent Static Lateral Load Method and Response Spectrum Method as per suggested by the Indian Standard Seismic Code (IS 1893: 2002 Example: The beam shown has constant cross-section and it is made from homogeneous isotropic material. defines the shape of the equivalent lateral force pattern, and depends on the period of the structure. (25 mm); or, the smallest nominal shear 13th World Conference on Earthquake Engineering Vancouver, B. The pile group is acted upon by a ver- tical force P = 444. Generalized Procedure. Equivalent lateral force for an earthquake is defined as a set of lateral force which will produce the same peak response as that obtained by dynamic analysis of structures . However, the complex nature of the lateral torsional buckling phenomenon makes it hard to embrace all the affecting factors and assumptions. Equivalent Lateral Force Procedure 12. Hieber, John F. A significant revision to this procedure, which more closely reflects the ground motion Re: Equivalent Lateral Force Method. 4 includes some provisions for the special wind regions indicated, near mountainous terrain, and near gorges. y Special method using equilibrium of fluid Q. Static Nonlinear Analysis Methods . , and Hago, A. methods, i. applied +1 conversion factor: m increases (ok, expected) . Kircher,d) M. As discussed above, the nominal shear capacity is determined as the least of: the capacity infill corner crushing; the horizon-tal component of the force in the equivalent strut at a racking displacement of 1 in. ƒ The building is square in plan with five 28-ft bays totaling 142 ft – 3 inches out to out in each direction. Eberhard 9. Fx = Lateral force at level x Cvx = Vertical distribution factor V = total design lateral force or shear at the base of the building wx and wi = the portions of W assigned to levels x and i hx and hi = heights to levels x and i k = a distribution exponent related to the building period as follows: k = 1 for buildings with T less than or equal to 0. The shearing force suffers sudden changes when passing through a load point. or Coulomb formula. A: In the presentation an example was presented of a structure analyzed using a response spectra analysis. method that splits vertically the whole frames into separated simple frames, each one containing only one bay subjected to lateral loads which is calculated from the dimensions of all the bays. Find the deflection, slope and the location and value of maximum slope. 45 kips-sec 2/ft The subscript is an integer index. So if your lateral load has an arm to it, you are forced to abandon this equation. These methods are typically a conservative approximation of the behavior of the structure during a seismic event. 4 defines the pressures (with the exception of the lateral/side wall pressures) that need to be computed for wind loading from the E/W direction. Frame Structures with Lateral Loads: Cantilever Method the entire frame acts similar to cantilever beam sticking out of the ground. beams are all examples of compression elements. Stanton, Marc O. How is Equivalent Lateral Force abbreviated? ELF stands for Equivalent Lateral Force. 45 m) long and 7. The Newton-Rhapson method is an example of an appropriate numerical method. In practice, beams carry very small axial force and undergo negligible axial deformation. wacker, david g. The actual equivalent lateral stiffness, a. the lateral load resistance) attracts higher. 49 2. Determine the force main diameter. 1) Take the stiff lower structure on its own, taking no account of the presence of the flexible upper structure. Example 1: Intermediate moment resisting frames lateral force resisting system. 0 m beyond the upper 9. SEISMIC LOAD . Some examples have been made to compare the latter method with linear analysis. ” The basic idea of the proposed innovative method was developed through the force method to obtain the lateral deformation and stiffness of 2D building structures. Equivalent static lateral force method and Response spectrum method. 3 Algorithm for ASCE 7-05 Seismic Loads. Force. • If sliding resistant force(R) is less then 1. An Example Problem. hieber, john f. Seismic Analysis Using UBC And IBC Codes,Equivalent Lateral Force Analysis in STAAD Pro v8i. 6 . 8? Maximum diaphragm deflection Envelope Method Allowed for semi -rigid modelling Is diaphragm untopped steel decking or Wood Structural Panels Idealize as flexible Is span to depth ratio ≤ 3 and having no horizontal irregularities ? Is diaphragm concrete slab or concrete filled steel deck ? The lateral tire force estimation scheme has been designed, and it consists of the following three steps: the yaw moment estimation based on a disturbance observer, the sum of the lateral tire force of two front tires and two rear tires estimation based on a least-square method, and individual lateral tire force estimation based on a heuristic method. The two most common methods are to use a combination of structural ductility applied to short period structures and equal displacement to long period ones, with  2. There is no type of force that is a lateral force but there are lateral forces possible on a body with a directional coordinate system. 1 shows the lateral pressure diagram on a wall of height H retaining water. Equivalent static lateral force analysis is based on the following Response spectrum method and Time history method. The roots of equation (D-41) are summarized in Table D- 1, as taken from Reference 1. The fundamental assumptions underlying the lateral force procedure are that: Clause 4. Then, the mentioned procedure was expanded into 3D building structures. The equivalent lateral force at the base of the structure, Ve , is calculated. EERI, Martin W. AISC classifies cross-sectional shapes as compact, noncompact The “two feet additional soil” as machinery loading will increase lateral pressure on wall by : No increase to lateral pressure due to “bridge” effect. WORK UNIT NO. 5 m along the upper 9. Structural requirements • Horizontal force (P) to wall push wall for sliding. It is very simple and quick method. However, Method for Determining Equivalent Lateral Seismic Force One of the analytical procedures permitted in ASCE 7 for calculating seismic loads is the equivalent lateral force procedure. It is essential to estimate and specify these lateral forces 2. The analytic methods of analysis and design of earthquake resistant structures are complex, even with the equivalent lateral force method allowed by the IBC. 4 refers to the American Society of Civil Engineers’ Minimum Design Loads for Buildings and Other Structures (ASCE 7-02) Section 9. Detailed Example Structure Description; Implementation of the Equivalent Lateral   10 May 2015 BUILDING USING EQUIVALENT STATIC METHOD” submitted by Mr. 9) Where C s seismic response coefficient as defined below W the total dead load and 25% of live loads in storage areas and permanent equipment The following expression is The Parallel Force Method In the parallel force method, sometimes referred to as the component method (Figure 2), the reactions of the gusset at the beam and column interfaces are assumed to act parallel to the brace force. Received: 01/08/2014 Accepted: 11/10/2014 the calculated horizontal component of the force in the equivalent strut at a horizontal racking displacement of 1. redundants. This lateral force distribution is expressed as 19 Performance-Based Plastic Design (PBPD) Procedure Figure 3-1 (continued) Analysis of Tall Buildings Using A “Moment-Force Transformation Method" As a Simplified Method of Analysis Maaz Siddig Ibrahim and Abdelrahman Elzubair Mohamed 2Department of Civil Engineering, College of Engineering, Sudan University of Science and Technology. A foundation bolt placement template may be used to locate and support the foundation bolts during fabrication of the foundation and to further secure the frame foundation interface. Lateral Forces on Retaining WallsENCE 454 ©Assakkaf Level Backfill (cont’d) – Where is the height of earth and Kp is the coefficient of passive earth pressure: – Note that Kp usually varies from 2. 3 m) high walls 28 Table 5 Test matrix for two story assemblies and tall walls 28 The vertical component of the force in the equivalent strut is added to the design shear for the bounding beam or slab. 2. Since the forces are parallel, they obvi-ously do not intersect at a common point, as is the case with the UFM. the equivalent lateral force (ELF) procedure. The requirement for a suitable lateral force distribution for the displacement-based design of SPSW systems, in general, is the primary motivation for the work presented here. Figure 1. ƒ Story heights are 23 ft from the first to second floors and 13 feet for the remaining 19 stories; the overall building height is 270 feet. 6 kN (8 kips). The Equivalent Lateral force method is a static method where the base shear and the corresponding distribution of the pseudo-static force is based on only the Fundamental mode. story levels. • The number of redundants is. 12. with current code distributions; 2) this force distribution also gives a very good esti-mateof maximumcolumn momentdemandswhen the structures are responding to se-vere ground motions and deform into the inelastic range; 3) higher mode effects are well reflected in the proposed design lateral force distribution. Concrete 4. 3 m) high walls 27 Table 4 Test matrix for 11. -like a truss, depends on diagonal members to provide load path for lateral forces from each element to foundation. Shear walls a. Other factors such as soil type and seismicity also have a role on earthquake effects. 8-2) For T ≤ TL Cs = SD1 /T[R/I] = 0. (25 mm) V n /1. A magnitude of prestressing force is selected to “balance” or counteract some portion of the load. Equivalent Load 3. The torque is then distributed to each shear wall in relation to its relative stiffness and its distance from the stiffness centroid. Heinrich Muller-Breslau, the force method was one of the first methods available for analysis of statically indeterminate structures. The example EOC is assumed to be located in Oakland, California, a region of very high seismicity Of the recognized three dimensional standard methods of seismic analysis of multistory structures are the Equivalent Lateral Load method and the more sophisticated Response Spectrum Method. method involves the seismic design of a SPSW system considering a certain . Lateral Load Analysis of Waterfront Structures Supported on Plumb Piles J. 2 is similar in its basic concept to SEAOC recommendations in 1968, 1973, and 1974, but several improved features have been incorporated. 2- Eqn. For this purpose, the design example in Chapter 7 of FEMA P752,  1 Oct 2014 both force-based and displacement-based design methods, and Example of a Liquefaction Triggering Analysis for a Single SPT Boring (Idriss and simple lateral force was applied to the structure equal to a specified  19 Feb 2014 determined using either the Equivalent Lateral Force Procedure of Section 12. PERFORMING ORGANIZATION REPORT NO. Build and analyze a computational model in accordance with the Equivalent Lateral Force Method to determine force and drift demands under seismic loads. In this configuration, shear walls resist forces by allowing the sheathing panel to rotate, essentially racking Lateral force microscopy (LFM) can probe lateral stiffnesses that are not accessible to normal-force AFM, resulting in higher spatial resolution. This chapter presents an example in which an equivalent lateral force (ELF) analysis is performed for a five-story reinforced concrete building with intermediate moment frames resisting load in one direction and shear walls resisting the load in the other direction. These methods are in compliance with EN 1998 and ASCE 7-10 standards. Example 2 :  The user is able to select from several methods for the calculation of equivalent lateral forces. 5. According to 5. Two main methods are presented: α – method used to calculate the short-term load capacity of piles in cohesive soils and β – method used to calculate the long- term load capacity of piles in both cohesive and cohesionless soils. As compatibility is the basis for this method, it is sometimes also called as compatibility method or the method of consistent displacements. List and define the conformance checks required of all the analysis methods. Example 1: Analysis of the offshore pile group shown in Fig. 6 Lateral force method of analysis 6. , modified equivalent lateral force procedure (ELF) and The two examples demonstrate that the relative seismic weight between the lower. For seismic lateral force calculation, Equivalent Static Force Method is most commonly . In normal force measurements, the cantilever is moved normally to the surface. • Primary objective of the force method is to determine the chosen set of excess unknown forces and/or couples –. Examples that illustrate the difference and the limitations of the two prime methods are presented in addition to the study of  1 Oct 2018 The upper portion is analyzed with the equivalent lateral force or modal are based on analysis methods where the diaphragm is modeled as  The Equivalent Static Analysis method commonly performance of a building using the method of inertial forces, method of maximum energy and For example, the new edition to the. In a curve, an angle of attack is generated in relation to the outer wheels to the rail. The theoretical bases of the equivalent lateral force and the response-spectrum analysis procedures of the 2000 NEHRP Provisions for damping or energy dissipation systems were presented in the paper. 4 kN·m (240 ft-kips), and a horizontal force H = 35. Elastic analyses using the equivalent lateral force (ELF) procedure and the continuous medium method (CMM) are utilized to establish initial proportions for the CCW system, and to determine the design forces and moments. A method is proposed, and used, to generate geometryless, force-matched stimuli to compare the role of lateral force during active and passive touch, while minimizing other cues. 8 for mm 1. Apply a dummy force to the top of the upper structure, calculate the resulting deflection at the level of the applied force, and work out k = F/d. k eq , of the building at the target displacement, ∆t, can be determined from the results of a static pushover analysis. No near-field or soft-soil histories were included in the set of 20 histories. Columns and Banking a turn allows some of the G-forces created in the turn to increase the weight on the tires, increasing the traction. these equations represent vertical loads. 2(7) the equivalent horizontal forces have the design value of φ N Ed at the top and bottom of each column, where N Ed is the force in each column; the forces at each end are in opposite directions. lateral torsional buckling. Isolate the section of fluid (Section ABC with a unit perpendicular length) Step 2. This force is friction. The hand solution from EFM is also used for a detailed comparison with the analysis and design results of the equivalent cross sectional area of the diagonal numerically equals the diagonal length, l: 22 A l h b ef . BRIDGE CONSTRUCTION IN SEISMIC REGIONS 6. 8 kN (100 kips), a moment M = 325. Yeliz Firat 2 1,2: Berger/Abam Engineering, Inc. PERFORMING ORGANIZATION NAME AND ADDRESS 10. Equivalent Lateral Force and Modal Analysis Procedures for Buildings with Damping Systems Oscar M. 8-11 of ASCE 7-10. 2 Two Stage Analysis Procedure A two-stage equivalent lateral force procedure is permitted to be used for structures having a flexible upper portion above a rigid lower portion, provided the design of the structure complies with all of the following: a. Calculation of Design Seismic Force by Dynamic Analysis Method 7 3. Calculate the wind pressure: . This method is by far the most convenient method and recommended by PTI. 4. Aust. Constantinou,b) M. C. A new lateral force distribution based on study of inelastic behavior is developed by using relative distribution of maximum story shears of a number of example structures subjected to a variety of earthquake ground motions. 8 65 b. For pure shear (ie, ignoring rotation), you'll do a similar procedure but using forces instead of moments/torque and ignore the contribution of the walls perpendicular to the force. 928 MODIFICATIONS ON EQUIVALENT LATERAL FORCE METHOD Where a flexible structure is placed atop a relatively rigid structure, ASCE permits the use of a two stage equivalent lateral force procedure. •When a building is subjected to an earthquake, it undergoes vibrations. 3 base shear force and distribution of the horizontal forces along the elevation . Furthermore, it is mandatory to provide lateral bracing to achieve stability against lateral forces for example wind loads. The first example is a single-story masonry warehouse building with tall, slender walls. 6. Washington State Transportation Center (TRAC) University of Washington, Box 354802 11. • Since the beam is indeterminate to the second degree assume the location of two points of inflection to analyze by the equations of statics. apply -1 conversion factor: m stays the same (not ok, not expected) Equivalent static force analysis • The concept is a dynamic analysis into partly dynamic and partly static analyses for finding the maximum displacement. Response spectrum method is a linear dynamic analysis method. 6 second were used for the analysis. Scaling of the analysis results can be further understood by an example. For example, AFMs have been used to study the compliance, stiffness, adhesion, and frictional properties of biological and nonbiological samples. Equivalent Lateral Forces are applied as one concentrated force at the mass center of each storey of the building. 18 lateral force is resisted by the diagonal strut. AUTHOR(S) 8. The following list provides an acceptable geotechnical theory for the development of the lateral earth pressures and potential external loads Thus, the spring constant is: G=. (13) where is the lateral force at i-th storey and is the mass of i-th story. 5 shows how the various parts are separated. Force (Flexibility) Method Directly gives desired displacements and internal member forces • • Easy to program in a computer Additional steps are necessary to determine displacements and internal forces • Can be programmed into a computer, but human input is required to select primary structure and redundant forces. 93 Gs adds weight to the wheels. 8 160 3. The figure below shows the applied loads (F 1, F 2 Chapter 2. The lateral force, the yaw moment, and the longitudinal force obtained previously must, respectively, be equal to the total force of the tire lateral forces, the total yaw moment produced by the tire forces, and the total tire longitudinal forces. 080 (Eq. Example - Example 1. 48 2. • The transverse loads cause internal shear forces and bending moments in the beams as shown in Figure 1 below. 30, depending upon area seismicity. 2 =35. is also a representation of the influence of tendons by using equivalent loads. This method can be used in FLAC to establish the at-rest condition in the numerical model. The analysis also allows a calculation of the soil reactions ky. Moreover, internal pressures which caused by the behavior of liquid fresh concrete, is acted on vertical formworks. performing organization report no. The area of the strut used for that analysis is determined by multiplying the strut width from Equation 1 by the specified thickness of the infill. 214 (Eq. The A lateral force resisting system according to the present disclosure includes a metal lateral force resisting panel and holdowns. Paul Smith-Pardo 1 & G. • Assume points of inflection develop at a distance of 0. To figure out what portion of the Gs gets adds weight to the tires, you multiply the G-forces by the sine of the banking degree. 1617. For a short cylinder the coefficient of drag is 0. MODAL AND RESPONSE SPECTRUM (IS 1893:2002) ANALYSIS 0F R. • The Japanese engineer Toshikata Sano independently developed in Using the spin buttons you can vary the value in increments. Methods of Analysis include: 1. Use the Portal Method to calculate the corresponding (i) applied loads P 1 and P 2, (ii) column bending moments, (iii) beam axial forces. The bending Moment diagram is a series of straight lines between loads. and has a basic lateral and vertical seismic force-resisting system conforming to one of the types indicated. There is a new group related to this method. 8. Concrete Formwork Loads and Pressure Calculations. 2-49. The assumptions made to develop these procedures regarding the force-displacement response of yielding building frames were identified. 3 feet (3. The force main diameter is determined in Step 1, part B. The equivalent lateral force (ELF) procedure specified in Sec. The lateral force method of analysis. Many, if not all, of the walls separating the dwelling units are used as interior shear walls in the transverse direction. Calculation using the equivalent lateral force method. The Nonlinear Static Procedure in these documents, based on the capacity spectrum method, involves several approximations: The lateral force distribution for pushover analysis and conversion ofthese results to the capacity diagram are based only on the fundamental vibration mode ofthe elastic system. 5 shows the mechanism in which one wheelset generates . 64 65. most critical load combination defined by either Equation C-17 or C-18. couples their dynamic response. Problems on Lateral Load Analysis by Portal Method 1. The basic rating life of a bearing according to ISO 281 is where L10 = basic rating life (at 90% reliability), millions of revolutions C = basic dynamic load rating, kN P = equivalent dynamic bearing load, kN p = exponent for the life equation = 3 for ball bearings Example 15. This method is called the Neutral Earth Pressure Method and is covered in the text by Gregory Tschebotarioff. Describe the similarities and differences in Modal Response Spectrum Analysis and Linear Response History Analysis and explain how these methods can be formulated into a “unified” seismic analysis methodology. 24 newtons per meter. Conversely, dynamic methods use response spectrum analysis and time history Building codes such as the Uniform Building Code (UBC) or International Building Code (IBC) require the determination of Equivalent Static Lateral Forces in order to compute effect and to perform checks on the structural design. The method postulates that the dis- placement response of the structure for ground motion can be described with one (or both x', y' directions) mode shape. Download Staad File. with axial, lateral, and rotational stiff­ nesses that are a function of both the pile and the structural characteristics of the connection. Weber Course Content Content Section 1 Retaining walls are structures that support backfill and allow for a change of grade. 01 (Eq. (2) The equivalent modulus of elasticity of the diagonal E ef can be determined as 2 ef ef Gd l E hb. Problem . Introduction. 5. 7 Results Dynamic analysis has been carried out on the building by using two methods, i. A beam is considered to be unrestrained when its compression flange is free to displace laterally and rotate. The bounding frame design should also take into consideration the volumetric changes in the masonry infill material that may occur over time due to normal temperature and moisture variations. W. 4 meters A typical force vs. 8-5) 1 using rayleigh method . In this lateral force estimating method, the detected lateral acceleration, roll angle acceleration, yaw angular acceleration and a roll angle, and based on the stored position of the center of gravity of the vehicle, the ground position lateral acceleration is calculated. ” Examples include pipe racks. In addition to causing acceleration, forces cause objects to deform – for example, a force will stretch or compress a spring; or bend a beam. Whereas, in the Response Spectrum analysis, program solves the Eigen Solution to determine the other mode shapes and the corresponding natural frequencies. This process is experimental and the keywords may be updated as the learning algorithm improves. 1 Seismic Reponse Coefficient Cs = SDS /[R/I] = 0. Therefore, the employment of such a load pattern does not guarantee the optimum use of Beam Stiffness. Complete force calibration of the lateral signal in LFM requires measurement of the lateral signal deßection sensitivity as well. For both expressions in Equations C-17 and C-18, the total horizontal force is Ω 0QE. In this method, a Lateral Forces on Retaining WallsENCE 454 ©Assakkaf Level Backfill (cont’d) – Where is the height of earth and Kp is the coefficient of passive earth pressure: – Note that Kp usually varies from 2. EERI, Charles A. 4 distribution of the horizontal forces to individual frames Thus the lateral pressure on a vertical surface retaining water is equal to γw. • “Elastic First Mode” lateral load pattern is the lateral force that assigned to each story which is depended to the product of the magnitude of the elastic first mode and the mass in each story. 1 - NONBUILDING STRUCTURES VERSUS NONSTRUCTURAL COMPONENTS • Example 13. • As the wall moves towards (into) the soil backfill (right side of Figure 2), the passive condition develops and the lateral pressure against the wall increases with Force (Flexibility) Method For determinate structures, the force method allows us to find internal forces (using equilibrium i. “Mat hematical model for lateral stiffness of shear walls with openings. Instructional Material Complementing FEMA 451, Design Examples. In this method, the structure is represented by a single-degree-of-freedom system with stiffness equal to the secant or effective stiffness and viscous damping represented by the effective damping at the calculated displacement. 0 m below the mudline (top two layers of soil), and at 1. Basic principle. Fortunately, there are easier ways to measure forces. 3- Most soils reports limit lateral soil pressure to something like 2,500 psf/ft. It is then distributed to the storeys according to the selected method. Table D-1. 8 65 2. done by the equivalent lateral forces with the internal plastic work done at the. The line of action of this force is at height h = 6. AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation. Sliding resistance comes from the friction force generated by the total weight (W)(weight of wall plus any soil’s weight over the footing) and resistant force from soil the wall sliding into, if there is . Example 5 - Load Replacement. Plugging into the equation: 1. Standard . 0) Therefore it is important for everyone to do their due diligence to make sure that all works are complete and accurate. According to EN 1998 point 3. A comparison of both methods for earthquake multistory building presented here. Structural Analysis The Equivalent Lateral Force method and the. 3465 cos 3º G h 41. Lateral torsional buckling may occur in an unrestrained beam. w P V(x) M(x For example, let’s say you want to determine the wind load on an antenna that is 3 feet long with a diameter of 0. Equivalent static load earthquake force analysis method, Civil Engineering. Will add a vertical loading on top of wall and increase loading to wall footing, hence affect on the pressure the footing to the foundation soil (contact pressure). 25 lbs is the amount of wind load on the antenna. , Al-Oraimi, S. When an applied load causes both lateral displacement and twisting of a member lateral torsional buckling has occurred. As a nonbuilding structure, consideration of seis-mic effects on pipe racks should be in accordance with ASCE 7 Chapter 15, which refers to other chapters as applicable. These reactions can be checked against the allowable lateral pressures determined from theory and soil strength parameters @). so-called “handbook method” is used to calculate the basic rating life . Therefore, pseudostatic seismic forces generated in Robot are scaled so that the sum of reactions for the main seismic direction equals the base shear force. – Building supports four filter units connected in a fashion that . 157 305 0. The slope of the lines is equal to the shearing force between the loading points. It offers a simplified method for finding the design forces for structural members for earthquake. The two design procedures shown in ACI 318-14: Direct Design Method (DDM) and the Equivalent Frame Method (EFM) are illustrated in detail in this example. Masonry 4. work unit no. Response Spectrum Method of Analysis. Eurocode 8: Seismic Design of Buildings Worked examples 2. The equivalent lateral force method is allowed for all buildings in SDC B  Equivalent static method _ IS 1893 part ___explanatory examples . h where h = the height of water above the point considered. Key Words: Equivalent Lateral Force Method, Response Spectrum Method, IS 1893: 2002 (Part-I), modification factor, building especially for single story building so I have decided force reduction factor. The change is equal to the load. 3 – Lateral load calculation by modal analysis method (earthquake in X-direction)  5. 9) Where C s seismic response coefficient as defined below W the total dead load and 25% of live loads in storage areas and permanent equipment The following expression is Also, it is assumed that lateral load Vs is equal to the design lateral force that is given by Ve divided by R. Johnson,e) M. 3 m) high walls 28 Table 5 Test matrix for two story assemblies and tall walls 28 force; the direction of motion of the mass tells us the direction of the force. 13) is calculated incorrectly in RSAPRO both for Type 1 and Type 2 spectra. Exception: Basement walls may be designed using active pressure, provided the basement wall is 6-feet or less in height and is supported by a flexible floor system. If they were not then, for example someone brings in heavy equipment or  15 Sep 2018 Base shear is an estimate of the maximum expected lateral force that will the use of the equivalent static force procedure and a dynamic lateral force procedure. 26 Feb 2013 2. Such comparisons have been extremely hard to make because of the difficulty to meaningfully match the many factors involved [4-8]. •UBC and IBC provide a static method of solving for those values. Location of Centre of Mass 10 4. 4, calculated along a bed joint. Determined the basic wind speed, V, in accordance with ASCE 7 Figure 6-1 or IBC Figure 1609, assuming the wind can come from any direction. Columns are usually thought of as straight vertical members whose lengths are considerably greater than their cross-sectional dimensions. Common k h values range from 0. To obtain the global nodal forces, we will first define the product of Kd to be Fe, where Fe is called the effective global nodal forces. author(s) 8. 0 in. Load Balancing: Introduced by T. performing organization name and address 10. Computation Target Displacement: network is determined by using Table A-2. 0 Unported Two Stage Equivalent Lateral Force Procedure. F. The equivalent lateral force procedure as contained. 35 meters; 0. These values are explained in detail below. equal to the degree of static indeterminacy of the structure. Force Components of the Elastic Method. Typical floor plan and an elevation are shown in Figures 1 and 2. It provides a technique for performing an equivalent static lateral load analysis. design of precast concrete piers for rapid august 2005 bridge construction in seismic regions 6. • In this  involved the application of 10% of the building weight as a lateral force on the structure, There are examples in the new generation of earthquake loading . Traditional method of estimating lateral pressure due to surcharge load. 5a, 5b) Strength (Weak Story) Irregularity. buildings. An example of a three dimensional frame member is given in Figure 2. P 2. of two methods, an Equivalent Lateral Force and a performance based time history. 5 for the commonly used equivalent lateral force procedure. One of the analytical  For example, all shear wall buildings will have similar amou force whereas force distribution estimated by either of these methods is a set of equivalent. EFP refers to "Equivalent Fluid Pressure," where you can enter a lateral soil pressure in psf per foot of depth. 1 (1) the response is governed by the first translational mode in the horizontal direction in which the analysis is performed (2) a simple approximation of the shape of that mode is possible, The goal of this structural seismic design example is to calculate the seismic design force and seismic base shear for a reinforced concrete building structure. ELF⫽equivalent lateral force procedure; RSA⫽response-spectrum analysis earthquake histories that matched on average a 2000 NEHRP Provisions response spec- trum with parameters SDS⫽1. 4 112 3 86000 112 1 3 4 2 3 3 Shear Walls 10 Shear Walls with Openings Qamaruddin, M. Of the recognized three dimensional standard methods of seismic analysis of multistory structures are the Equivalent Lateral Load method and the more sophisticated Response Spectrum Method. Lateral Force Distribution as per Torsion Provisions of IS 1893-2002 (Part I) 12 6. This multiplier can be used to reduce the calculated (unscaled) base shear below the base shear value obtained by the Equivalent Lateral Force Method. Lateral forces (LFs) are experienced when a virtual or defines the shape of the equivalent lateral force pattern, and depends on the period of the structure. This comparative study is defined as the reviewing some of research reports on analysis of multi-story building using Equivalent Lateral Force Method and Response Spectrum Method. The total base shear is calculated and then distributed along the height of the building. Chapter 13 – Masonry presents the design of two common types of buildings using reinforced masonry walls as their lateral force resisting system. Lateral Pressure Method: Here you can choose between E. The lateral loads are independently resisted by shear walls. -efficient, rigid system. 7% x 582,973) = 21,570 kN. to analyze the given building in. We will use the equivalent lateral force procedure. The direction component of the stress is parallel to the applied force direction. Figure 4. For this purpose, were used the Equivalent Lateral Force (ELF) Method, Modal Failure BR-47, for example, cuts the state of Minas Gerais and has already  9 Aug 2010 Equivalent Lateral Force method in ASCE/SEI 7-10, as well as pushover . The deflection of beams is much larger than that of axially loaded elements, and thus the problem of bending is more critical in design than other types of deformation. ELF is defined as Equivalent Lateral Force somewhat frequently. 5 times of sliding Chapter 2. Lateral force resistance to wind and seismic loads in wood frame structures is provided by shear walls in the majority of homes (Shirazi and Pang 2012). Lateral force method The lateral force method called also Equivalent static load method, partly eliminates the disadvantages of the previous method with simplification in certain cases. 18-1 is limited to a depth of 12 ft (3. These methods are in compliance with EN 1998 and ASCE 7-10  Lateral Force Distribution as per Torsion Provisions of IS 1893-2002 (Part I). For instance, a bicycle is moving forward with the coordinate system aligned with the frame. based on Statics) irrespective of the material information. is the element displacement vector. Site- specific The example addresses these issues and illustrates that isolated structures. In the conventional seismic design methods, heightwise distribution of equivalent seismic loads seems to be related implicitly on the elastic vibration modes. This example demonstrates how to use the equivalent length method to calculate the pressure loss through simple pipe and fitting arrangement. 1 12. • Is restricted only to a single mode of vibration of the structure. View Full Document. It should be clear that the element stiffness matrix is of crucial importance it links – nodal forces to nodal displacements; it encapsulates how the element behaves under load. condition develops and the lateral pressure against the wall decreases with wall movement until the minimum active earth pressure force (Pa) is reached. (including all connections), other than the diagonal strap, should be designed based on these loads. This course only provides information concerning the Load Balancing method of analysis. Usual values for this vary from 1,000 psf to 4,000 psf or more. The lateral force resisting system for the flexible upper portion is typically built with wood-framed shear walls sheathed with wood structural panels (WSP). 3 EQUIVALENT LINEAR ANALYSIS Equivalent Lateral Force Method: 1. Lateral Force Tractive Force Aligning Torque Rolling Resistance and Overturning Moments Steering System Models Examples of Steering System Effects Steering Ratio Understeer Braking Stability Influence of Front-Wheel Drive Driveline Torque About the Steer Axis Influence of Tractive Force on Tire Cornering Stiffness Influence of Tractive Force on Aligning Moment Approximate Lateral Load Analysis by Portal Method Portal Frame Portal frames, used in several Civil Engineering structures like buildings, factories, bridges have the primary purpose of transferring horizontal loads applied at their tops to their foundations. moment frames in both directions as the lateral force resisting system. 15 May 2017 A Step-by-Step Summary of the Equivalent Lateral Force Procedure for the T, which is a function of the mass and stiffness of the structure. 5 s or more, k • “Equivalent lateral force (ELF)” proposed by Eurocode 8 CEN 2005( )is the force at any story which is dependent to the height of story and mass in that story: (15) where is the height of the i-th story above the base and k is equal to 1 for main period and k is equal to 2 for main period . • Example : BRIDGE CONSTRUCTION IN SEISMIC REGIONS 6. Nonbuilding Structures design examples • Example 13. Example 1: Rankine's lateral earth pressure with horizontal backfill (English units) Given: Height of earth at heel, H = 12 ft. 00001) for self-weight –non seismic. It can be calculated with analytical expressions, or more commonly, solved by structural design software. Draw a free-body diagram F1(F2): Pressure force on Horizontal (Vertical) plane Figure 1: Factors Affecting Lateral Behavior of Shear Walls . The basic theory of the cantilever moment distribution method and the application of this method to conduct the equivalent lateral force procedure for the seismic design of tall frames are discussed in detail. This section shall calculate an example for comparing the horizontal seismic action in. 0 m (Figure 4. Note that for this example we consider a flat system, with no elevation changes. 8 160 b. It also includes a check of the preliminary design using dynamic analysis as required by the Standard and a discussion of isolation system design and testing criteria. 8-3) Governs design > 0. The figure below shows the shear forces (kips) in the interior columns of a two-storied frame. Horizontal backfill, Unit weight of backfill soil: g = 115 lb/ft 3. An initially straight strut or column, compressed by gradually increasing equal and opposite axial forces at the ends is considered first. When modeling various types of structural systems, one of the goals of the analysis could be to come up with an effective value of stiffness and interpret its scope based on how we compute it from the structural problem at hand. equivalent lateral force method example

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