Design Earthquake Resistant Structures » structural Engineering http://articles.architectjaved.com/earthquake_resistant_structures Form follows function - that has been misunderstood. Form and function should be one, joined in a spiritual union - Frank Lloyd Wright Thu, 15 Dec 2011 20:11:23 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 Effects of Deformations in Structures http://articles.architectjaved.com/earthquake_resistant_structures/effects-of-deformations-in-structures/ http://articles.architectjaved.com/earthquake_resistant_structures/effects-of-deformations-in-structures/#comments Tue, 15 Jun 2010 00:13:06 +0000 Architect http://articles.architectjaved.com/earthquake_resistant_structures/?p=38 The inertia force experienced by the roof is transferred to the ground via the columns, causing forces in columns. These forces generated in the columns can also be understood in another way. During earthquake shaking, the columns undergo relative movement between their ends.

Deformation in a Structure

Deformation in a Structure

In the figure above, this movement is shown as quantity u between the roof and the ground. But, given a free option, columns would like to come back to the straight vertical position, i.e. columns resist deformations. In the straight vertical position, the columns carry no horizontal earthquake force through them. But, when forced to bend, they develop internal forces. The larger is the horizontal displacement u between the top and bottom of the column, the larger this internal force in columns. Also, the stiffer the columns are (i.e. bigger is the column size), larger is the force. For this reason, these internal forces in the columns are called stiffness forces. In fact, the stiffness force in the columns is the column stiffness times the relative displacement between its ends

]]> http://articles.architectjaved.com/earthquake_resistant_structures/effects-of-deformations-in-structures/feed/ 2 Earthquake Resistant Structures by Planning and Design Approach http://articles.architectjaved.com/earthquake_resistant_structures/earthquake-resistant-structures-by-planning-and-design-approach/ http://articles.architectjaved.com/earthquake_resistant_structures/earthquake-resistant-structures-by-planning-and-design-approach/#comments Tue, 15 Jun 2010 00:08:41 +0000 Architect http://articles.architectjaved.com/earthquake_resistant_structures/?p=57 Earthquakes have plagued man for millennia. It is a destructive force, which was once upon a time declared to be wrath of God for infidelity of human beings. But today, we understand what causes earthquakes, and can design effective mechanisms to mitigate the effects of earthquakes.

Haiti Earthquake 2010

Haiti Earthquake 2010

Basically, there is the Conventional approach to achieving earthquake resistance, then there is the basic approach, and nowadays, there are Active Control Devices which can counteract the effects of earthquakes on buildings.

Conventional Approach

Design depends upon providing the building with strength, stiffness and inelastic deformation capacity which are great enough to withstand a given level of earthquake-generated force.  This can be accomplished by selection of an appropriate structural configuration and careful detailing of structural members, such as beams and columns, and the connections between them.

Basic Approach

Design depends upon underlying more advanced techniques for earthquake resistance is not to strengthen the building, but to reduce the earthquake generated forces acting upon it. This can be accomplished by de-coupling the structure from seismic ground motion it is possible to reduce the earthquake induced forces in it by three ways.

  1. Increase natural period of structures by Base Isolation.
  2. Increase damping of system by Energy Dissipation Devices.
  3. Mitigate earthquake effects completely by using Active Control Devices.

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