 This is the learning outcome. At the end of this session, the student will be able to demonstrate the earthquake resistant conceptual design features in the structure. Design features. What are the levels of good design features? First is the integrity of the structure or building stability. Then the good design feature is the proper proportioning of the members and proper selection of the materials. Now, let us see the first is the structural integrity. Now, all the structural and non-structural element should be well connected so that they must behave as a integral building, integral structure. Now, structural element means slab which is sharing the load, transferring to the load to the beam. Beam is transferring the load at the ends through the column. Then columns are transferring the load at the column minute. So, these are the structural elements. Non-structural elements like infill walls, plaster components, then parapet walls. So, the structural component means load sharing components or elements, non-structural elements which are not sharing the loads. Though both must be connected in a proper manner so that they must behave as a integral or once a single box type action they must offer. Second is structural stability. So, in case of structural stability, first requirement is structural part should be available for effective transfer of forces to the foundation. Structural part means as I explained in integral integrity concept. The load of slab must be taken by the beam immediately. Load of beam must be transferred to the column beneath, the column must transferred to the column beneath and the columns final or the column at the plinth layer must transferred to the foundation. The effective load transfer means the load is transferred must be transferred in a systematic way so that there should be a proper transfer of the load for a good load part diagram. Second is the local geological conditions must be critically studied for the prefection settlement. So, major problem in earthquake is the differential settlement which will create or generate the additional moments at the beam column joints. So, that the differential moment settlement shall be avoided. For that purpose the soil must be studied geological condition must be critically studied and one more phenomena is there that is soil liquefaction. So, in earthquake liquefaction of soil is possible. So, those are geological condition must be tested so that the liquefaction of soil can be avoided. Now, next is structural members in which the first point is the proportioning. So, column and weak beam it does not mean that the beam must be weak it actually means columns are stronger than the beams while designing or while proportioning the structural members especially in portal frames columns must be always stronger than beams. Second is large cantilever portions should be avoided. Now, various times cantilevers are required cantilever portions like galleries, balconies sometimes porches also. One end is fixed another end is free in which deformations are more deflections are more and in case of earthquake these deflections are magnified. So, the deformation is the major problem in the earthquake excessive deformation that will strike the stability to the stability of the building so that large cantilever must be avoided. Next is the material what material we should select for the building the structure. Now, in case of earthquake whatever vibrations are induced those vibrations are to and flow vibration both direction. So, in that case stresses or nature of the stress will not be constant or same compressive zone may transfer into the tensile zone or tensile zone may transfer into the compression zone. So, the members stress reversible is possible. So, material must be used which must sustain the stress reversible just generally in case of brace beams of ESRs the stress reversal is possible although we cannot say that the compression is always at top and tensile tension is at bottom. So, this because of earthquake the tension may be at top and compression at bottom also. Second is it must deform structure or material must deform deformations are expect accepted even expected also in the earthquake resistant design without deformation of the energy cannot be dissipated, but during the deformation there should not be any failure or the deformation must be ductile type of failure better mode is not expected in the earthquake. So, material must deform without failure. Now, let us see this is the basic theme of this presentation. You can see here the frame in first case you can see the plastic hinges are formed in the columns only. Now, during vibration the inelastic deformation may occur at this plastic hinges mechanism may form and the column may separate into pieces. So, this is also called as columns way mechanism whenever columns are separated in the pieces means where plastic hinges are formed first in the column. So, in that case column will fail and the story or floor which is supported by these columns will come down. This is global type of failure. So, when beams and columns are designed which are having equal section or beams are stronger than the columns means columns are weaker than the beams the first plastic hinges will form into the columns column will fail first and failure of the column is the goal of global failure for that frame. So, the story which is supported on that column will come down. In the second figure or second part of this figure you can see here columns are stronger than the beams in this design. So, in whenever the columns are stronger than the beams plastic hinges are formed first in beams then after that the plastic engine will form into the column at one location you can see here. So, these are the plastic hinges which are formed in the beams. So, beams are stronger in flexure as well as in deformation also deformation capacity of the beam is more. So, large deformations are required to fail the beams and even when beams are failed. So, that much portion may fail which is called as a local failure of that frame instead of column first beam must fail and beam failure is considered or known as local failure for that we must design our columns stronger than the beams. So, this diagram also give us desired frame behavior which is expected in the earthquake. Now, after this entire discussion I will ask one question to you and that question is what type of failure is ensured by strong column weak beam design? You pause the video and just write down the answer may you can explain that answer in a system of manner also. Now, answer for this is the type of failure by strong column weak beam is local failure. Why local failure? Because this approach of strong column weak beam will give us the desired frame action frame behavior in which plastic hinges will form in the beams. So, that failure of the beams will be called as local failure and that failure of beams will be designated as the local failure for the frame also. Now, next term or next theme is the appropriate stiffness. Why appropriate stiffness? Approve stiffness must not be more or even the lower stiffness that will be also dangerous in the earthquake. Appropriate stiffness why it is so? So, which will reduce or minimize resonance effect? Resonance effect means the matching of frequency of earthquake and building or the structure if the frequency matches then the structure will not come at rest until and unless an external efforts are applied. Second is to achieve the functional requirement. So, appropriate stiffness means that if you provide higher sections for the beam probably your height of the building will reduce. If you provide very higher sections for the columns your carpet area of the building may restrict. So, that proper or appropriate stiffness will give us a proper functional requirement also. Third is the control of deformations. Stiffness is required for the controlling deformation not to restrict the deformation ok. Deformations are expected accepted in the earthquake, but those deformations must be controlled that is only possible by appropriate stiffness and fourth is to influence the failure modes. Now, what failure mode means the structure must behave ductile and failure mode of the structure must be ductile also. So, to influence that appropriate stiffness is required higher stiffness will attract more forces. So, that failure may be brittle failure. So, appropriate stiffness may give you the ductile type of failure. Now, this is one comparison again for the flexible structure and stiff structure. So, this is also called as the stiffness versus flexibility approach. Now, advantages are also listed and the disadvantages are also listed. You can see here flexible structures. So, it is suitable for short period and disadvantages though for long period these are very giving higher response. Second is ductility is easier to achieve and the flexible structures are more amenable to analyze. The disadvantages are flexible structures are difficult to reinforce. If you want to make the flexible structure, flexible sections are small and reinforcement is providing reinforcement is very difficult. And in case of stiff structure these are suitable for long period sites, but very higher response is expected on short period sites. Now, whatever lacunas are there in the flexible structure disadvantages these are actually advantages in case of stiff structures you can see here. Now, in case of stiff structures easier to reinforce stiff reinforced concrete walls means stiff structure means generally basically building the shear walls or reinforcement is quite simple in the shear walls. But appropriate ductility is not easy to achieve in case of stiff structures. And last is non-structural remains are easier to detail means other structural remain non-structural remains their diagrams their detailing is very simple and stiff structures are less amenable to analysis. This is the reference for this video. Thank you.