COMPARATIVE STUDY OF DIFFERENT STOREY BUILDINGS FOR SEISMIC FORCES
Introduction:
ETABS is a specialized engineering software designed for the comprehensive analysis and design of multi-story buildings. The acronym "ETABS" stands for "Extended Three-Dimensional Analysis of Building System."
Aim/Objective:
1. Utilize ETABS software to extract various seismic responses of a structure and manipulate specific properties.
2. Understand the elements that impact the dynamic characteristics of a building.
3. Comprehend the factors that affect the natural period of a building.
4. Gain insights into the factors influencing the mode shapes of oscillations.
> Now, let's discuss the provided data.
Procedure:
Steps to implement the provided data.
1. Access the ETABS main page.
2. Navigate to File -> New Model and apply the following configuration.
3. Press the "OK" button.
For BUILDING A:
4. Grid spacing and story data:
5. In the new model quick template, provide the specified choices for grid and story dimensions as demonstrated below.
6. Select "Edit Grid Data".
7. Select "Edit story Data".
8. Press "OK".
9. The subsequent screen will appear.
10. To define material properties for rebars, follow these steps:
i. Click on "Define."
ii. Select "Material Properties."
iii. Choose "Add New Material."
i. Click on "Define."
ii. Select "Material Properties."
iii. Choose "Add New Material."
11. Press "OK" and then choose the option to select a new material for concrete.
12. To define section properties for beams, follow these steps:
i. Click on "Define."
ii. Choose "Section Properties."
iii. Select "Frame Section."
iv. Opt for "Add New Property."
v. Specify the shape as a rectangle.
i. Click on "Define."
ii. Choose "Section Properties."
iii. Select "Frame Section."
iv. Opt for "Add New Property."
v. Specify the shape as a rectangle.
13. To add a beam size of B300x400, and for reinforcing details of the beam, follow these steps:
i. Add a beam with the size B300x400.
ii. To provide reinforcement details for the beam, click on the "Modify/Show Rebars" button. Input the following data.
i. Add a beam with the size B300x400.
ii. To provide reinforcement details for the beam, click on the "Modify/Show Rebars" button. Input the following data.
14. Press "OK".
15. For columns, click on "Add New Property".
15. For columns, click on "Add New Property".
16. Choose the shape as a rectangle.
17. To provide reinforcement details for the column, click on the "Modify/Show Rebars" button and input the following data.
17. To provide reinforcement details for the column, click on the "Modify/Show Rebars" button and input the following data.
18. Press "OK".
19. For slabs, navigate to "Define" -> "Section Property" -> "Slab Section" -> "Add New Property".
19. For slabs, navigate to "Define" -> "Section Property" -> "Slab Section" -> "Add New Property".
20. Click "OK".
21. To define load patterns, navigate to "Define" -> "Load Patterns".
22. enter additional loads and apply the provided data, follow these steps:
i. Click on "Add New Load" after entering the relevant data.
ii.Then, select "Modify Lateral Load" for both seismic types as specified.
i. Click on "Add New Load" after entering the relevant data.
ii.Then, select "Modify Lateral Load" for both seismic types as specified.
23. Press "OK".
24. To define the mass source, go to "Define" -> "Mass Source" -> "Modify/Show Mass Source".
24. To define the mass source, go to "Define" -> "Mass Source" -> "Modify/Show Mass Source".
25. Include the mass multiplier for the load pattern as previously instructed, and then click "OK".
26. To review the load cases, navigate to "Define" -> "Load Cases".
26. To review the load cases, navigate to "Define" -> "Load Cases".
27. To generate a load combination, follow these steps:
i. Go to "Define" -> "Load Combination".
ii. Select "Add Default Design Combination".
i. Go to "Define" -> "Load Combination".
ii. Select "Add Default Design Combination".
28. PRESS OK
29.The combination has been successfully created.
30. MODELLING
31. To model a column, proceed with the following steps:
30. MODELLING
31. To model a column, proceed with the following steps:
i. Click on the Quick Draw Column icon located in the panel.
ii. Choose the column property type as C400X400.
iii. Select the "All Story" option in the bottom right corner.
iv. Position the cursor on the grid and click to create the column as demonstrated below.
ii. Choose the column property type as C400X400.
iii. Select the "All Story" option in the bottom right corner.
iv. Position the cursor on the grid and click to create the column as demonstrated below.
32. To create a beam, follow these steps:
i. Click on the Quick Draw Beam icon in the panel.
ii. Choose the beam property type as B300X400.
iii. Select the "All Story" option in the bottom right corner.
iv. Position the cursor on the line between the grids and click to create the beam as illustrated below.
i. Click on the Quick Draw Beam icon in the panel.
ii. Choose the beam property type as B300X400.
iii. Select the "All Story" option in the bottom right corner.
iv. Position the cursor on the line between the grids and click to create the beam as illustrated below.
33. To create a slab, follow these steps:
i. Choose the "Similar Stories" option located in the bottom right corner.
ii. Click on the plan icon at the top of the panel.
iii. Select "Storey 1" from the options provided.
ii. Click on the plan icon at the top of the panel.
iii. Select "Storey 1" from the options provided.
34. To create slabs, perform the following steps:
i. Click on the Quick Draw Floor icon.
ii. Choose the slab property type as S150.
iii. Click inside the frame.
iv. The slabs will be generated in the similar stories.
i. Click on the Quick Draw Floor icon.
ii. Choose the slab property type as S150.
iii. Click inside the frame.
iv. The slabs will be generated in the similar stories.
35. To assign loads to specific elements, follow these steps:
36. For Beams:
i. Navigate to "Select" -> "Select" -> "Property" -> "Frame Section".
36. For Beams:
i. Navigate to "Select" -> "Select" -> "Property" -> "Frame Section".
37. To specify the beam type, follow these steps:
i. Choose the beam type.
ii. Go to "Assign" -> "Frame Loads" -> "Distributed".
i. Choose the beam type.
ii. Go to "Assign" -> "Frame Loads" -> "Distributed".
38. Provide the load pattern and load as indicated previously.
For slabs, select the slab property as S150.
For slabs, select the slab property as S150.
39. To select the slab section:
i. Navigate to "Select" -> "Select" -> "Property" -> "Slab Section".
ii. To assign uniform shell loads:
iii. Go to "Assign" -> "Shell Loads" -> "Uniform".
ii. To assign uniform shell loads:
iii. Go to "Assign" -> "Shell Loads" -> "Uniform".
40. Select the previously mentioned load pattern and load, then click "OK".
i. Next, go to "Select" -> "Select" -> "Property" -> "Slab Section".
ii. Select "Assign" -> "Shell" -> "Diaphragms" -> "D1".
41. Press "OK".
42. Save the model by following these steps:
i. Go to "File" in the menu bar.
ii. Select "Save As" to save the model with a chosen file name and location.
42. Save the model by following these steps:
i. Go to "File" in the menu bar.
ii. Select "Save As" to save the model with a chosen file name and location.
43. To perform the analysis:
i. Click on the "Run Analysis" button located in the top panel.
ii. After the analysis is complete, the deformed shape of the building will be displayed.
ii. After the analysis is complete, the deformed shape of the building will be displayed.
For BUILDING B
Save as:
44. Go to File -> Save as 'ETABS Project 1b'
Adding Stories:
45. To add extra stories, go to Edit -> Edit story and grid system -> Modify/ Show story data
46. Place the cursor on the arrow cell and right click -> add story -> keep existing story heights, and then give the below option in the dialog box.
47.Change similar to option to story 1.
48. Click refresh view.
48. Click refresh view.
Loads:
49. Click Display shell load assign icon in the panel, Change the load pattern to live and click apply and ok.
49. Click Display shell load assign icon in the panel, Change the load pattern to live and click apply and ok.
50. Click Display frame load assigns icon in the panel, Change the load pattern to wall and click apply and ok.
51. Select the slab S150 and assign it as diaphragm as mentioned in earlier steps.
Analysis:
52. Click run analysis icon.
For BUILDING C
Save as:
53. Click File -> Save as -> ETABS Project 1c
53. Click File -> Save as -> ETABS Project 1c
54. Changing column property:
55. Go to Define -> Section property -> Frame section
55. Go to Define -> Section property -> Frame section
56. Select the column and click Modify/ show property
57. Change the column size to 550X300.
58. Click ok
58. Click ok
59. Changing Column orientation in X- direction:
60. Click Select -> Properties -> Frame section
61. And select the column which created now and click Select.
62. Click Assign -> Frame -> Local axes.
60. Click Select -> Properties -> Frame section
61. And select the column which created now and click Select.
62. Click Assign -> Frame -> Local axes.
63. Give Orientational degree as 90.
64. Select the slab and assign it as diaphragm.
Analysis:
64. Click run analysis icon.
64. Click run analysis icon.
For BUILDING D
Save as:
65. Click File -> Save as -> ETABS Project 1d
66. Changing Column orientation in Y- direction:
67. Click Select -> Properties -> Frame section68. And select the column which created now and click Select.
69. Click Assign -> Frame -> Local axes.
70. Change angle to 0.
71. Select the slab and assign it as diaphragm.
Analysis:
72. Click run analysis icon.
For BUILDING E:
Save as:
73. Click File -> Save as -> ETABS Project 1e
Adding stories:
74. To add extra stories, go to Edit -> Edit story and grid system -> Modify/ Show story data.
74. To add extra stories, go to Edit -> Edit story and grid system -> Modify/ Show story data.
75. Place the cursor on the arrow cell and right click -> add story -> keep existing story heights, and then give the below option in the dialog box.
76. Change similar to option as story 1.
77. Click refresh.
78. Check the loading as mentioned in the earlier steps.
79. Changing column size:
80. Click Define -> Section property -> Frame section
80. Click Define -> Section property -> Frame section
80. Click column and select Modify/ show property.
81. Click ok
82. Click Add New property to create another column type C400x400
83. Changing top 5 floors column size:
84. Click Set display option, uncheck Beams and Floors option.
84. Click Set display option, uncheck Beams and Floors option.
85. Click ok.
86. Only column is visible.
86. Only column is visible.
87. Go to View -> Set building view limits
88. Select all columns.
89. Go to Assign -> Frame -> Section propert
90. Top 5 floor columns are changed to C400X400
91. Make Beams and floors visible again.
92. Select the slab and assign it to diaphragm.
92. Select the slab and assign it to diaphragm.
Analysis:
93. Click run analysis icon.
For BUILDING F:
Save as:
94. Click File -> Save as -> ETABS Project 1f
95. Changing column size:
96. Changing all column size to C600X600.
97. Click set display option and uncheck beams and floors
96. Changing all column size to C600X600.
97. Click set display option and uncheck beams and floors
98. Go to view -> Set building view limits, have option as follow.
99. Click ok.
100. Go to Assign -> Frame -> Section property and select C600X600.
100. Go to Assign -> Frame -> Section property and select C600X600.
101. Change the view to Base to story 10.
102. Select the slab and assign it to diaphragms.
102. Select the slab and assign it to diaphragms.
Analysis:
103. Click run analysis icon.
103. Click run analysis icon.
For BUILDING G:
Save as:
104. Click File -> Save as -> ETABS Project 1g
105. To add extra stories, go to Edit -> Edit story and grid system -> Modify/ Show story data.
106. Place the cursor on the arrow cell and right click -> add story -> keep existing story heights, and then give the below option in the dialog box.
107. Change similar to option as story 1.
108. Click refresh view.
109. Creating new column size:
110. Go to Define -> Section properties -> Frame section.
109. Creating new column size:
110. Go to Define -> Section properties -> Frame section.
111. Select C600X600 and click Modify/ Show property
112. Create a column size C800X800.
113. Select Add new property to create a new column size C600X600.
114. Assigning these column sizes to its respective floors:
115. Go to set display option and uncheck beams and floors.
115. Go to set display option and uncheck beams and floors.
116. Go to view -> set building view limits and give the settings
117. For top 5 Stories :.
117. For top 5 Stories :.
118. Select as a whole and assign C400X400 to it.
119. For middle 10 stories:
120. Follow the above procedure.
120. Follow the above procedure.
121. Select as a whole and assign C600x600 to it.
122. For bottom 10 stories:
123. It is already assigned as C800X800 in the beginning.
124. Check the loads in all the stories and also ensuring the diaphragms properties.
123. It is already assigned as C800X800 in the beginning.
124. Check the loads in all the stories and also ensuring the diaphragms properties.
Analysis:
125. Click run analysis icon.
125. Click run analysis icon.
For BUILDING H:
Save as:
126. Click File -> Save as -> ETABS Project 1h
127. Changing column size:
128. Click Set display option icon and uncheck beams and slabs.
128. Click Set display option icon and uncheck beams and slabs.
129. Select the column as a whole.
130. Click Assign -> Frame -> Section property
130. Click Assign -> Frame -> Section property
131. Click set display option and check beams and columns.
Analysis:
131. Click run analysis icon.
131. Click run analysis icon.
For BUILDING J:
Save as:
132. Click File -> Save as -> ETABS Project 1j
133. To increase 10% mass:
134. Click Select -> Select -> Properties -> Slab section.
135. Select S150 and click select.
134. Click Select -> Select -> Properties -> Slab section.
135. Select S150 and click select.
136. Click Assign -> Shell loads -> Uniform
137. Give load as 3.3 and select replace existing loads.
137. Give load as 3.3 and select replace existing loads.
138. Click ok.
139. Ensure the diaphragms properties
Analysis:
140. Click run analysis icon.
140. Click run analysis icon.
For BUILDING K:
Save as:
141. Click File -> Save as -> ETABS Project 1k
141. Click File -> Save as -> ETABS Project 1k
142. To increase 20% mass:
143. Click Select -> Select -> Properties -> Slab section.
144. Select S150 and click select.
145. Click Assign -> Shell loads -> Uniform
146. Give load as 3.6 and select replace existing loads.
146. Give load as 3.6 and select replace existing loads.
147. Click ok.
148. Ensure the diaphragms properties
Analysis:
148. Click run analysis icon.
148. Click run analysis icon.
RESULTS:
* The results have been taken from the Tables from respective building models.
149. Click Tables -> Analysis Results -> Structural output -> Model Information -> Model periods and Frequencies-> Show table
150. Click File -> Open, for respective building model.
BUILDING E:
BUILDING F:
BUILDING G:
BUILDING H:
* The results have been taken from the Tables from respective building models.
BUILDING H:
BUILDING J:
BUILDING K:
* The results have been taken from the Tables from respective building models.
BUILDING A:
BUILDING B:
BUILDING F:
BUILDING H:
* The results have been taken from the Tables from respective building models.
BUILDING B:
BUILDING C:
BUILDING D:
* Maximum storey displacement in X and Y direction:
BUILDING B (EQX):
B (EQY):
BUILDING C (EQX):
C (EQY):
BUILDING D (EQX):
D (EQY):
* The results have been taken from the Tables from respective building models.
Save as:
151. Open the file B and save as -> EATBS Project 1b zero
152. Defining the beam:
153. Click Define -> Section properties -> Frame section.
154. Select the existing beam and click modify.
153. Click Define -> Section properties -> Frame section.
154. Select the existing beam and click modify.
155. Change the below properties
156. Click ok.
Analysis:
157. Click Run analysis
Analysis:
157. Click Run analysis
* The results have been taken from the Tables from respective building models.
158. Open the Building H.
159. Click File -> Save as -> ETABS Project 1h zero
159. Click File -> Save as -> ETABS Project 1h zero
160. Click Define -> Section properties -> Frame section
161.Select C800x800
162. Give the above changes
Analysis:
163. Click Run analysis icon
163. Click Run analysis icon
* The results have been taken from the Tables from respective building models.
164. Open Building B
165. open file -> Save as -> ETABS Project 1b fixed
165. open file -> Save as -> ETABS Project 1b fixed
166. Go to plan view select base
167. Select all the joints at the base
168. Click Assign -> Joints -> Restraints
169. Change it to fixed
168. Click Assign -> Joints -> Restraints
169. Change it to fixed
170. Analysis:
171. Click run analysis
171. Click run analysis
