AULA 4 - FUNDAÇÕES (BEC - IFPB Cajazeiras)

Introduction

This tutorial provides a comprehensive guide on the design of associated footings (sapatas associadas) for up to two columns and continuous footings (sapatas corridas). It is based on the lecture by Prof. Lucas Pessoa from the Instituto Federal da Paraíba and aims to help civil engineering students and professionals understand the fundamental concepts and practical examples of foundation design.

Step 1: Understanding Footing Types

Begin by familiarizing yourself with the two main types of footings discussed in the lecture:

• Associated Footing: Designed for a maximum of two columns. It distributes the load from the columns to the ground effectively.
• Continuous Footing: Used for multiple columns in a line, providing a stable base across a longer span.

Practical Tips

• Ensure you know the loads applied by the columns to design the footings accordingly.
• Consider soil characteristics when choosing between associated and continuous footings.

Step 2: Determining Footing Dimensions

Calculate the dimensions for associated and continuous footings based on the load and soil bearing capacity.

For Associated Footings

1. Calculate Load: Determine the total load from the two columns.
2. Soil Bearing Capacity: Check the soil's bearing capacity (in kN/m²).
3. Footing Area Calculation:
   • Use the formula: [ \text{Area} = \frac{\text{Total Load}}{\text{Soil Bearing Capacity}} ]
4. Determine Dimensions: Choose dimensions that fit the calculated area and provide stability.

For Continuous Footings

1. Load Calculation: Similar to associated footings, calculate the total load from the columns.
2. Footing Width and Depth:
   • The width typically ranges from 1.2 to 2 times the depth based on structural requirements and load distribution.
3. Use of Reinforcement: Ensure proper reinforcement to prevent shear failure.

Step 3: Reinforcement Design

Design the reinforcement for both types of footings to ensure structural integrity.

Reinforcement Guidelines

• Follow local building codes for minimum reinforcement requirements.
• Use high-strength steel bars for better performance.
• Ensure proper spacing and cover to avoid corrosion.

Step 4: Practical Examples

The lecture presents three practical examples of footing design. Apply your knowledge by working through these examples or similar scenarios:

1. Example 1: Calculate the dimensions and reinforcement for an associated footing with two columns.
2. Example 2: Design a continuous footing for three columns with varying loads.
3. Example 3: Analyze a scenario where soil conditions change and adjust your designs accordingly.

Common Pitfalls to Avoid

• Neglecting local soil conditions can lead to inadequate footing design.
• Underestimating load requirements can compromise structural safety.
• Failing to check building codes can result in non-compliance.

Conclusion

Understanding the design and implementation of associated and continuous footings is crucial for any civil engineer. This tutorial provided foundational knowledge, practical calculations, and examples to apply in real-world situations. As the next steps, consider practicing more design calculations and exploring advanced topics in foundation engineering to deepen your understanding.