Civil Engineering Principles and Practices

Retaining Walls and Structural Safety

• Retaining walls must resist applied earth pressure structurally.
• Designs should prevent overturning from lateral pressures.
• Safety measures are essential against sliding.
• Weep holes are typically placed near the bottom, not the top, to drain retained water.

PSDP and PERT Terms

• PSDP: Public Sector Development Programme.
• PERT stands for Project Evaluation Review Technique.

Procurement Regulatory Authorities

• PPRA: Public Procurement Regulatory Authority.

Civil Engineering Principles

• Pre-qualification aims to shortlist relevant firms and reduce project costs.
• Inertia force to elastic force ratio is referred to as the Mach number.
• Successful bidders are determined by the lowest evaluated responsive bidder (LERB).

Fluid Mechanics and Concrete

• The total energy of a particle in perfect incompressible fluid remains constant in continuous streams.
• Plain cement concrete has different strengths in compression and tension.
• Fineness modulus indicates relative sizes of coarse and fine aggregates.
• For a 1:2:4 concrete mix, approximately 0.574 m³ of coarse aggregate is needed per cubic meter.

Engineering Materials and Specifications

• Froude number is vital in analyzing fluid flow scenarios involving gravity and wave making.
• An RCC column is considered long if its slenderness ratio exceeds 12.
• Liquid waste pipes specifically designed for human excreta are termed soil pipes.
• Modular ratio affects the depth of a critical neutral axis in beams.

Structural Analysis

• Maximum deflection in a cantilever beam occurs at the free end.
• Propped cantilever beams have one end fixed and the other end supported.

Safety and Building Standards

• Factor of safety is calculated as ultimate stress to working stress.
• Compressive strength of mortar according to BCOP should not be less than 500 Psi.
• Ground acceleration values vary by seismic zone classifications.

Miscellaneous Topics

• Inspection of bridges in rainy seasons is categorized as routine survey.
• Special surveys focus on condition assessments conducted periodically.

Construction Practices

• ASTM code C-94 specifies standards for ready-mix concrete.
• The moment of inertia for a rectangular section is given by ( \frac{bh^3}{12} ).