Analysis & Design of RCC shear walls in the model using ETABS

Analysis & Design of RCC shear walls in the model using ETABS:

ANSWER:

AIM:

To Run the analysis and design the RCC shear walls (show in the etabs model). The following challenge deals specifically with the shear wall of size 300x1500 at grid A-11 in the structural model.

• Extract values of longitudinal steel ratio, boundary element length and shear reinforcing ratio from the design results.
• Provide cross sectional steel arrangement of the shear wall from its base up to terrace, in compliance with provisions of IS 13920 – 2016. AutoCAD application can be used for this exercise. Alternatively, it can be drawn by hand as well.
• Provide elevation drawings of the reinforcement details of the shear wall from base up to terrace.

INTRODUTION:

In this challenge we are detailing the rinforcement for shear walls of size 300x1500 at grid A-11 in the structural model. A shear wall consists of detailing of reinforcemnt like vertical and horizontal reinforcement-web and boundary elements. These are subjected to alternative lateral loads (eq).

hence we are design the details of shear walls as per below codal provisions.

• Classification of shear wall as per the clause 10.1.4 of IS 13920:2016.
• Minimum vertical reinforcement within the boundary element from table 1 of section (iii)- as per IS 13920:2016.
• Horizontal reinforcement in the shear wall as per codal provision IS 13920:2016 of table 1-section(iii).
• The providing of maximum dia of rebar of shear wall as per clause 10.1.8 of IS 13920:2016.
• Confining reinforcement spacing for boundary element as per clause 10.4.4 of IS 13920:2016.
• Confining reinforcement Within boundary element as per clause 10.4.4 IS 13920:2016.
• minimum reinforcement in Rc shear wall as per clause 10.1.6 of IS 13920:2016.

PROCEDURE:

• Initially open the ETABS software.
• open the given etabs file.
• the go to the Analysis model.check if there is any errors.
  
• After that run analysis the model.
• then Go to the Shear wall design in the etabs provided at the top.
• Now select the .and go to the view- view select objects only.
• Then visible of selected columns only.
  
• Then done the shaer wall design in the etabs provided at the top right corner.
• shaer wall design-design preferences.
• 
• then change the elevation to A then it visible the both the columns .
• Longtudinal reinforcement:
  for A-11 shear wall
  
  
  
• NOw shear reinforcement:
• For A-11 shear wall
  
• reinforcement deatils for pier egde or boundary width of shear wall.
  
• Now we have Find the longitudinal and shear or transverse reinforcement details for the A-11 shear wall and drawn in the auto cad file as shown in the below figure.

Design summary for the shear wall.

DESIGN CRITERIA:

1. Classification of shear wall type as per the clause 10.1.4 of IS 13920:2016.
   `h_w/l_w= 21000/1500=14>2`
   From the above we can say as the Type of shear wall as slenderwall.
2. Longitudinal Reinforcement:
   1. From the etab results it shows the maximum longitudinal or vertical reinforcement=`13128 mm^2`
      now we are providing the 25mm Dia of bar with ast=`490mm^2`
      henece to find the no.of bars `13128/490= 28`bars+2bars forsupport of confinement reinforcement.totally 30nos of bars are provided.
      Total provided for longitudinal reinforcement=`13720mm^2`
   2. Vertical reinforcement in boundary region=`0.008*1500*300=3600mm^2`
      we provided at left side region=`5390mm^2`
      we provided at right side region=`4410mm^2`hence safe at boundary zones.
   3. Vertical reinforcement in web region=`0.0025*1500*300=1125mm^2`
      But we provided is3920mm^2 hence safe.
3. Shear / Horizontal reinforcement:
   1. From the etabs results we should provide `750mm^2`
      But we provided 8mm`phi`@ 100mm c/c.So AST provided =`1000mm^2`
      
   2. Shear reinforcement for boundary edges as per clause10.4.4 of IS 13920:2016.From the given formulae.
      `A_(sh)=0.05 *s_v*h*f_(ck)/f_y`
      Where `s_v=100mm`
      h=600-80=`520mm`
      `f_(ck)=25n/(mm^2)`
      `f_(y)=500n/(mm^2)`
      Hence obatined
   3. For left side =`ash=0.05*100*520*25/415 =156mm^2`2 legged.
      So provided 10mm dia of bars @ 100mm c/c.
      
   4. For Right side =`ash=0.05*100*370*25/415 =111mm^2`2 legged.
      So provided 8mm dia of bars @ 100mm c/c.

Now showing the detailing of reinforcement of shear wall A-11 in auto cad drafting.

RESULT:

• The given etabs model is checked and anaylsed by using the etabs software.
• For the given model we have carried out the shaer wall design.
• stuided the maximum area of steel required for lognitudnal and shear reinforcements at confinement zone for A-11 shear wall.
• we have provoded the sufficient area of steel as per their codal provisions of IS 13920:2016.
• For the details we have also draft the drawing in the auto cad.

REPORT:

Calculations are shown above.

DETAILS	SHEAR WALL	REQUIREMENT	PROVOIDED	SAFE
longitudinal/ vertical reinforcment	A-11
1.total area of steel required.		`13128 mm^2`	`13720mm^2`	ok
2.confinement zone @ right		`3600mm^2`	`4410mm^2`	ok
3.confinement zone @ left			`5390mm^2`	ok
4. @ web zone		`1125mm^2`	`3920mm^2`	ok
Shear / horizontal reinforcement.	A-11
1.shear reinforcement		`750mm^2`	`1000mm^2`	ok
2.confinement zone @ right		`156mm^2`	So provided 8mm dia of bars @ 100mm c/c.	ok
3.confinement zone @ left		`111mm^2`	So provided 10mm dia of bars @ 100mm c/c	ok