Civil and Architectural Engineering Department-College of Engineering-Sultan Qaboos University
Comparison between Required and Provided Reinforcement in Villa Design at
Muscat Area during the Period 2000-2005
Khoula Moosa Al-Mazrui
Abstract
A comparison between required and provided reinforcement in villa design at Muscat area during
the period 2000-2005 was conducted in this research. The comparison included structural redesign of 20 villas using the same geometry and material strengths provided in the drawings
approved by Municipality drawings. The only variable was the amount of reinforcement. The aim
was to investigate the possibility of over-design structures in villa design in Muscat area,
Sultanate of Oman. The 20 villas were designed using STAAD-Pro software and the Reinforced
Concrete Council Design Spread sheets to BS8110:97.
The reinforcement found in the drawings was called the provided reinforcement while the
reinforcement resulted from the redesign process was called the required. The selected villas for
redesign were scattered in different locations in Muscat area and were designed by different
consultants of small to medium size offices. All drawings were approved for construction during
the period 2000-2005. The slabs and footings were designed using RCC spread sheets while the
frame analysis and design of beams and columns were done using STAAD-Pro commercial
structural design software. The weight of the required and provided reinforcement was calculated
for twenty villas using an in-house Spread Sheet Program developed by Dr. Ali S. Alnuaimi.
A clear case of over-design was found in all villas. Some individual members were underdesigned indicating inconsistency in the use of the code or improper structural design. There was
no clear trend or reduction in the differences between the required and provided reinforcement
over the time which indicates almost no improvement in the design process over the years from
2000 to 2005. The percentages in differences between the required and provided reinforcement in
the total amount of reinforcement of the whole villa ranged from 26 to 105 %. The percentages in
differences in the total amount of reinforcement for slabs of each villa ranged from 27 to 136 %.
The percentages in differences in the total amount of reinforcement for beams of each villa ranged
from 26 to 103 %.
The percentages in differences in the total amount of reinforcement for columns of each villa
ranged from 3 to 78 %. The percentages in differences in the total amount of reinforcement for
footings of each villa ranged from 20 to 124 %.