 in RC building. This is the C.G. Kunapuri, assistant professor, department of civil engineering, Walshchand Institute of Technology, Sulapuri. So, this is learning outcome for the students. Student will be able to apply the earthquake resistant measures in RC buildings. Now following are the measures which are shall be taken into RC buildings and which are discussed in this session. First is on hill slope, shear wall shall be provided for the building. Second thing while designing the frame members, especially columns and beam, the design of member shall be followed in this way that is strong column and weak beam. Third is buildings with soft story. So, the measure for soft story that is also explained in this third point. Fourth is avoid or avoiding short column effect in the frame members, how it is to be avoid what measure shall be taken that is discussed in this fourth. And last is provision for opening in shear wall. So, let us start one by one. Now this is the sketch which is showing you the building G plus 4 building and it is on hill slope and several times this practice is done as the height of the columns are required the columns are provided and because of the slope you can see here the height of the column is depth is very small and here it is little increasing. Finally, the height of column at this level is higher as compared to this. So, this what happens as the height of the column is increasing this lateral stiffness of the column is going to reduce. So, this building lateral stiffness for 3 these 4 columns is less. So, that is why your building is having lower having lower stiffness on this side and for this column the height is very small. So, short column effect may be also possible. So, what is to be done what is the remedial measure for this type of configuration that is provide shear walls for this side. So, the lateral stiffness of the building will increase. Now the second most important measure that we should take in the design of members is that we should provide column stronger than the beam. So, it does not mean that strong column weak beam it does not mean in this way actually whatever requirement of there for the section of the beam we should design that beam, but while designing the column the column section must be stronger than the beam this is the meaning of the strong column weak beam concept. What is the requirement of this concept always in this frame members column the shear lateral shears are acting on the columns and that column are filling in shear. So, the ductility or ductile failure column is not possible in this design approach beam failure is always filling in a flexure or it will go under deformations that is why it takes more energy more earthquake vibrations are required for that and that is why that failure is called as the local failure. So, weak beam and strong column design is desirable means what strong column if columns are filling your building will fail globally means and all the floors are coming down. Now third approach or third most important measure in RC building that we should take that is the building on soft first story. Now soft story what is mean by soft story or soft first story. So, this is ground story. So, the first story of building is this one G plus 1, 2, 3, 4 this building is shown here A what is shown here 1, 2, 3, 4 these four floors or four stories are with infill walls and brick masonry shown here. But basic concept is that the infill walls are used and at this ground story means the first story where infill walls are not present. So, what happens here? So, stiffness discontinuities observed here or this story is the lateral stiffness is very low as compared to the story above. What is the difference in this? If you observe this that these diagonal lines are shown means what this these infills are acting as the diagonal members. So, these diagonal members will generally add little stiffness or most stiffness in your building stories. So, that will help to reduce the drift and in ground story the infill walls are not there whose lateral stiffness is very low. So, sudden change in stiffness or stiffness discontinuities arising in this configuration. So, your build soft story will fail fast. Now, this B configuration is shown again the same guy is there G plus 1, 2, 3, 4, but at this intermediate of central level the shear wall is provided. But at ground story column or shear wall is not present. So, it is absent here. So, what happens? This story will be treated as soft story because shear wall or column is not present due to which the stiffness lateral stiffness of this story is low than the lateral stiffness of these 1, 2, 3, 4 story. So, again there is a problem of difference or discontinuity in the stiffness. So, this story is treated as the soft story. So, earthquake forces will hit this story and before you are this ground story will fail fast. You can see here this philosophical concept of the soft story. Building with soft story or soft first story behave as inverted pendulum during the earthquake. So, that inverted pendulum concept is very dangerous in earthquake. So, the entire thing is concentrated at the mass and that will vibrate that will shake severely which will increase the seismic response also. Large deformations in the ground floor columns has to be accommodated. The building collapses due to failure of first story and P delta unstable. P delta P is applied force delta is occurred deformation. Now, how the first story will fail? That is explained here the same sketch G plus 1, 2, 3, 4, 5 story building. Now, if the lateral stiffness of your first story is very low that will be treated as the soft story. So, due to that earthquake forces the plastic hinges are formed just bottom of the beam of column joint. So, columns are failing. So, all your story above will come down. So, your building will be subjected to global failure. Now, the question for all of you. What is the question? The story acts of story in a building due to there are four options A mass discontinuity, B strain discontinuity, C stiffness discontinuity and D low strength. What is the answer? You pause the video think on this story why it is act it will act as a soft story and give me the answer ok. The answer is C stiffness discontinuity because of stiffness discontinuity the story will act as a soft story ok. So, what is the remedial measure for this? Building is there especially in apartment buildings or ownership buildings the ground floor is kept for parking vacant for parking. For parking purpose the infill walls are not constructed at the ground level or the second one more approach is there the why the height of column or story is required as the story above. Height of the parking floor is always 2.5 meter 8 feet. So, the height of column is reducing lateral stiffness will reduce because of that the ground story will act as a soft story and there will be the damage. Now, what remedial measure is required for this? At corners of the building at least you provide wall it may be a shear wall RC shear wall. So, that makes your structure more stiff it may be infill walls at least you go for infill walls at this corner. So, it will add lateral stiffness into this story. So, failure is failure chances may be less and you can keep these four base vacant empty. So, that your movement is also possible. So, the model ground floor plan for building with parking that is shown here this is the remedial measure. Second thing is that your ground story is to be designed for 2.5 times the story shear. So, you calculate the lateral shear coming on this story and multiplied by 2.5 and then design your ground floor or this ground floor ground story for 2.5 times the story shear. Next feature or mixed are remedial measure is we should avoid the short column effect there are two examples very good examples are shown here. So, this is one story in which masonine floor is provided. So, that masonine floor ends the column here and this much column is a short column and the short column it is subjected for bursting or the crushing of the material. So, the masonine floor that will create the short column effect and the columns will fail in this locations ok. And in second sketch the opening is provided here the infill wall is there actually infill wall must be from one corner to another corner. So, that it will act as a diagonal member here that is not ensured. So, opening is provided that is why this much column will act as a short column and your column will fail here because infill wall is present up to this point to this point. So, after that for this column there is no any restraint provided. So, that is why this column will fail. So, let us avoid this types of short column effect by not providing this types of opening or masonine floors ok. Now, this is the provision for opening in the shear wall. This is shear wall and openings are there for the windows and these types of coupling beam beams are provided. This is the reinforcement arrangement which must be provided at the opening corners of the shear wall. So, it is explained well in next sketch ok. You can see here reinforcement in the coupling gears these are the horizontal bars and these are inclined bars with few ties and the vertical ties are also provided at these couplings. These must be provided at the openings ok. These are the references for the presentations or for this session. Thank you.