DCOM Volume I Appendix D

Appendix D: Structural Design of Concrete

Concrete members used in water structures range from Walls, Slabs, Roofs and Floors. Design of Reinforced Concrete should ensure these structures have sufficient resistance to cracking, adequate strength and does not allow leakage. Three methods or approaches are available for structural design of concrete, these are described below:

Working Stress Method:

• Produces uneconomical section,
• Produces stable section.

Ultimate Load Method

• Produces cheaper section,
• Produces unstable section.

Limit State Method

• Produces economical section,
• Produces stable section.

For design of water structure it is recommended to use Limit State Design Method, design of structural members should consider two design limits;

Limit of Collapse Design:

• Take care of safety of structure
• Deals with all types of forces Shear Force, Bending Moment, Torsion Moment ,
• Design criteria is the resistance offered by structure should not be less than limit value set in design code
• The appropriate loading value in the structure is based on loading combination of Dead Loads, Live Loads, Wind Load and Earth Quake Load as provided in BS 8110 code.
  

Limit of serviceability Design:

• Take care of control, deflection, cracking, abrasion and corrosion,
• The calculated values of deflection shall be less than the permissible values of deflection,