Details:

Creators:
El Fattah, Ahmed Mohsen ABD ; Rasheed, Hayder ; Esmaeily, Asad
El Fattah, Ahmed Mohsen ABD ; Rasheed, Hayder ; Esmaeily, Asad Less -
Corporate Creators:
Kansas State University. Transportation Center
Corporate Contributors:
United States. Dept. of Transportation. Research and Innovative Technology Administration
Subject/TRT Terms:
[+]
Bridge Design Columns Compressive Strength Confined Concrete Ductility Load Factor Reinforced Concrete Bridges Software Structural Analysis
Publication/ Report Number:
K-TRAN: KSU-11-3
Resource Type:
Tech Report
Geographical Coverage:
Kansas
Corporate Publisher:
Kansas. Dept. of Transportation. Bureau of Materials & Research
NTL Classification:
NTL-HIGHWAY/ROAD TRANSPORTATION-Bridges and Structures;NTL-HIGHWAY/ROAD TRANSPORTATION-Design;
Abstract:
The analysis of concrete columns using unconfined concrete models is a well established practice. On the

other hand, prediction of the actual ultimate capacity of confined concrete columns requires specialized nonlinear

analysis. Modern codes and standards are introducing the need to perform extreme event analysis. There has been a

number of studies that focused on the analysis and testing of concentric columns or cylinders. This case has the highest

confinement utilization since the entire section is under confined compression. On the other hand, the augmentation of

compressive strength and ductility due to full axial confinement is not applicable to pure bending and combined

bending and axial load cases simply because the area of effective confined concrete in compression is reduced. The

higher eccentricity causes smaller confined concrete region in compression yielding smaller increase in strength and

ductility of concrete. Accordingly, the ultimate confined strength is gradually reduced from the fully confined value fcc

(at zero eccentricity) to the unconfined value f’c (at infinite eccentricity) as a function of the compression area to total

area ratio. The higher the eccentricity, the smaller the confined concrete compression zone. This paradigm is used to

implement adaptive eccentric model utilizing the well known Mander Model.

Generalization of the moment of area approach is utilized based on proportional loading, finite layer procedure and

the secant stiffness approach, in an iterative incremental numerical model to achieve equilibrium points of P- and M-

 response up to failure. This numerical analysis is adapted to assess the confining effect in rectangular columns

confined with conventional lateral steel. This model is validated against experimental data found in literature. The

comparison shows good correlation. Finally computer software is developed based on the non-linear numerical

analysis. The software is equipped with an elegant graphics interface that assimilates input data, detail drawings,

capacity diagrams and demand point mapping in a single sheet. Options for preliminary design, section and

reinforcement selection are seamlessly integrated as well. The software generates 3D failure surface for rectangular

columns and allows the user to determine the 2D interaction diagrams for any angle  between the x-axis and the

resultant moment. Improvements to KDOT Bridge Design Manual using this software with reference to AASHTO

LRFD are made. This study is limited to stub columns.


Format:
PDF
Funding:
C1880
Collection(s):
US Transportation Collection University Transportation Centers
Main Document Checksum:
[+]
urn:sha256:1ded8d1591d0c0875928cc5ae98ab3d0cd89c409d9c8bf1d67e7f0915d4565e5
Download URL:
https://rosap.ntl.bts.gov/view/dot/23323/dot_23323_DS1.pdf
File Type:

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