The Effect of Lateral Loading on Civil Structures

868 Words4 Pages
Most civil structures will be subjected to some form of lateral loading during the span of their lifetime. Loads produced by earthquakes, wind, or blast explosions, mainly induce lateral displacement on structures. The effect of gravity loads acting through the structure’s lateral displacement has been called the P-∆ effect. This effect can initiate a pernicious circle against structural systems because the influence of gravity loads increase as the lateral displacement grows while at the same time, the lateral displacement is magnified as a consequence of gravity loads acting on them. From this short description, the nonlinear character of the problem is clear. Additionally, the possible incursion of structures into the realm of inelastic deformation further increases the complexity of this already difficult problem. 1.1. Historical perspective For many years, the P-∆ effect has been a subject of study and concern to structural engineers. In 1934 Ruge [1] made what was probably the first examination of the effects of gravity on the response of simple elastic structures. He was able to estimate the change in period and deflection of a vertical cantilever beam supporting a weight. In 1968, Jennings and Husid [2], also working with Single-Degree-Of-Freedom (SDOF) systems, were the first to report on the effects of gravity on inelastic structural response. They conclude that gravity increases the amount of plastic drift significantly over that found when gravity is neglected, leading in many cases to the collapse of the system. They also determined the critical value of the post-yield slope of the force-deformation backbone curve of the SDOF system above which collapse will not occur. Studies on the response ... ... middle of paper ... ... stability coefficient (θ), does not accurately represent inelastic P-∆ effects [9]. Increasing evidence shows that the use of elastic stiffness in determining theoretical P-∆ response of highly inelastic systems is unconservative [9]. Several researchers [6, 10, 11, 12] believe that the stability coefficient calculated based on the initial elastic stiffness is aimed to check the static stability of elastic or slightly inelastic structures only. Any procedure based on θ would be unable to capture inelastic response because the effective post-yield stiffness is underestimated [10]. For the usual design case of structures expected to respond beyond their elastic limit, Bernal [11] and Adam et al. [10] have suggested the use of two stability coefficients: one initial or elastic stability coefficient (θe ) and one inelastic stability coefficient (θi ).
Show More
Related

  • PREDICTION OF ASAPHALT PAVEMENT RUTTING USING FINITE ELEMENT THEORY

    2325 Words  | 10 Pages

    PREDICTION OF ASAPHALT PAVEMENT RUTTING USING FINITE ELEMENT THEORY Department of Civil Engineering, Faculty of Engineering Universiti Kebangsaan Malaysia, 43600 UKM Bangi Selangor, Malaysia. ABSTRACT The finite element method is capable of simulating the observed rutting of pavements subjected to axle load. Finite element modeling of pavements can be used directly to estimate primary response parameters without resorting to potentially costly field experiments. The

    Read More

  • Structural Reliability for the Design of Exceptional Structures

    1144 Words  | 5 Pages

    boundary layer. Vortex shedding appear as oscillating flow from opposite sides of a structure and engender fluctuating load perpendicular to the wind direction. Structural vibrations may occur due to resonance effect when the frequency of vortex shedding matches the natural frequency of the structure. Therefore, the Eurocode 1991-1-4 should not be used for buildings taller than 200m and very slender or unusual structures because it does not provide regulation on the following aspects: wind actions

    Read More

  • Anthony Hunt Case

    1659 Words  | 7 Pages

    University of Sheffield (Module: CIV1200: Introduction to civil and structural engineering design) The Work of Anthony Hunt Associates By: Nikhil Chaudhary 130153823 Content Introduction 1 Education and Training 2 Case Study

    Read More

  • Advantages Of Formwork

    9611 Words  | 39 Pages

    CHAPTER I 1.1 Introduction Formwork is defined as temporary structure whose purpose is to provide support and containment for fresh concrete until it can support itself. It moulds the concrete to the desired shape and size and controls its position and alignment. The development of formworks is parallel with the growth of concrete construction throughout the 20th century. The advancement of technology, increase of population and the space limitation lead the way to construct high-rise buildings.

    Read More

  • Reasons of the Failure of Tacoma Narrows Bridge

    2359 Words  | 10 Pages

    collapse of the Tacoma Narrows Bridge, all the static and dynamic strains should have been taken into account which would have involved proper consideration of effects of environmental conditions, building materials and design. I. Environmental conditions A. Effects and behavior of winds 1. Moderate winds, large oscillations 2. Wind effects on bridges 3. Transfer of wind 4. Vortices 5. Vortex streets 6. Vortex shredding 7. Frequency II. Building materials A. Properties of materials

    Read More

More about The Effect of Lateral Loading on Civil Structures

Open Document