Settlement of Rectangular Spreader Mat Calculator

Settlement Formula:

\[ S_{mat} = S_{plate} \times \left( \frac{B_{mat} \times L_{mat}}{D_{plate}^2} \right)^{0.5} \]

Settlement Observed in Plate Load Test:

Width of Rectangular Spreader Mat:

Length of Rectangular Spreader Mat:

Diameter of Circular Plate:

Settlement of Spreader Mat:

1. What is Settlement of Rectangular Spreader Mat?

Definition: This calculator estimates the settlement of a rectangular spreader mat based on plate load test results and dimensional relationships.

Purpose: It helps geotechnical engineers and construction professionals predict ground settlement under spreader mats used for load distribution.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ S_{mat} = S_{plate} \times \left( \frac{B_{mat} \times L_{mat}}{D_{plate}^2} \right)^{0.5} \]

Where:

\( S_{mat} \) — Settlement of the spreader mat (meters)
\( S_{plate} \) — Settlement observed in plate load test (meters)
\( B_{mat} \) — Width of rectangular spreader mat (meters)
\( L_{mat} \) — Length of rectangular spreader mat (meters)
\( D_{plate} \) — Diameter of circular plate used in test (meters)

Explanation: The formula scales the plate test settlement according to the area ratio between the spreader mat and test plate.

3. Importance of Settlement Calculation

Details: Accurate settlement prediction ensures structural stability, prevents excessive deformation, and helps design appropriate foundations.

4. Using the Calculator

Tips: Enter all dimensions in meters. Results include ±5% tolerance to account for soil variability. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is there a ±5% tolerance?
A: Soil properties can vary, and this accounts for potential differences between test conditions and actual field conditions.

Q2: What's a typical plate diameter for load tests?
A: Common diameters are 300mm (0.3m) or 600mm (0.6m), but any size can be used if properly documented.

Q3: When would I need a spreader mat?
A: Spreader mats are used when you need to distribute concentrated loads over a larger soil area to reduce settlement.

Q4: How accurate is this calculation?
A: It provides a reasonable estimate, but actual settlement may vary due to soil heterogeneity and other factors.

Q5: Can I use this for non-rectangular mats?
A: No, this formula is specifically for rectangular mats. Different formulas apply to other shapes.