1. Thesis Objectives by Rishabh Lala
Column Shortening in Tall Buildings Theory Validation and Designing Precepts
Thesis Objectives by Rishabh Lala

2. Phenomena Column Shortening Time Dependent Effects
Axial Shortening, creep, Shrinkage
Indian Standard Code Provisions

3. Estimation of Indian Scenario:
Objective I
Estimation of Indian Scenario:
In regards to provisions for column shortening, in Indian Standard Codes, and provisions that Indian Structural Designers are providing to accommodate this phenomena, in tall buildings.

4. Objective II Theory Validation:
Comparing the available theory as per Indian Codes (creep, shrinkage, elastic shortening), with results of column shortening obtained after detailed software analysis.

5. This is done in four steps:
Theory Validation
This is done in four steps:
Ds = Shortening between two columns
Ps1 and Ps2 = load coming on these columns
D1 and D2 Deflection manually calculated based on available theory, due to Ps1 and Ps2
l D1 - D2 l = Ds
=> Software Calculated Deflection = Manually Calculated Deflection
Theory Verified

6. Deflection Permissible:
Objective III
Deflection Permissible:
Permissible deflection (Dp) comes from ‘permissible slope’, which is obtained from literature review, especially Indian Standard Codes
To estimate, Permissible deflection (Dp) for Indian Scenario, using typical value of column spacing (L)
Using typical value of (L), Permissible loads (P1 and P2) to be determined, for typical column section.

7. Objective IV Relevant Height:
Height at which this phenomena becomes relevant, taking base as Indian Standard Provisions.
A height, for typical value of column spacing, in structure, after which it becomes compulsory to consider column shortening phenomena as a design consideration; is to be determined

8. Relevant Height
Building Model : 20 m, 40m, 60m, 80m, 100m, with typical column spacing
Loads : Dead, Live, Construction with FOS as per literature review
Analysis Type : Non Linear, construction Stage Analysis

9. Analysis Software MIDAS GEN 2015
One of the best software available for the analysis of column shortening, and construction stage analysis.

10. MIDAS GEN: 2015 Features: Manual Construction Stage Analysis
Enter Construction Stage specific Data
Check Results for Each Construction Stage
Check Column Shortening
Time Dependent Material Properties can be taken into account like Creep and Shrinkage
Burj Khalfa’s construction stage analysis was also done in Midas Gen 2010.