1980s Concrete Fallout Shelter Construction Manual and Plan

Introduction

Building a fallout shelter is a serious undertaking, but it can provide invaluable protection in the event of a disaster. This guide will walk you through the process of constructing a 10ft x 12ft x 8ft shelter with reinforced concrete walls and roof. The shelter must withstand 5psi overpressure and provide a protection factor of 40 for six adults. Follow these steps carefully to ensure your shelter meets all necessary safety standards.

Excavation and Structural Requirements

Excavation

Start by digging a 10ft deep chamber with 45-degree sloped sides for stability. This angle helps distribute the soil pressure evenly, reducing the risk of collapse. Use a backhoe or excavator to dig the hole, and make sure the sides are smooth and straight.

Soil Pressure Calculation

To ensure the stability of your shelter, you need to calculate the soil pressure using Terzaghi’s formula. This formula helps you determine the load-bearing capacity of the soil. Measure the soil’s density and angle of internal friction to plug into the formula. This calculation is crucial for reinforcing the structure properly.

Reinforcement

Reinforce the walls and roof with 12-inch thick walls and an 8-inch roof. Use 4,000 psi concrete that meets AISC standards. The walls and roof must be able to withstand 10,000 psi stress. Build concrete forms for the walls and roof, ensuring they are level and plumb. Pour the concrete in layers, compacting each layer to eliminate air pockets.

Modifications and Materials

Options

You have several options for building your fallout shelter. You can attach it to an existing basement, use CMU blocks, or build it into a hillside. Each option has its advantages and disadvantages, so choose the one that best fits your needs and resources.

Materials

For this project, you will need 12 tons of concrete, 1,500 lbs of rebar, 400 sq ft of waterproofing material, and 200 ft of steel piping. Gather all the necessary materials before you start construction to avoid delays.

Excavation Techniques

Different soil types require different excavation techniques. Clay soils, for example, require careful digging to prevent collapse. Sandy soils may require additional reinforcement to prevent erosion. Always consult a soil engineer to determine the best excavation method for your site.

Waterproofing

Waterproofing is crucial to prevent water damage and ensure the longevity of your shelter. Apply two layers of 60# felt and asphalt mastic, followed by a 20mil polyethylene sheeting. Use asphalt-based coatings to seal any cracks or seams. This multi-layer approach provides a robust barrier against water infiltration.

Construction Process

Step-by-Step Guide

Excavate the Chamber: Dig a 10ft deep chamber with 45-degree sloped sides. Ensure the sides are smooth and straight.
Build Concrete Forms: Construct concrete forms for the walls and roof. Use plywood or metal forms to create the desired shape.
Apply Waterproofing Layers: Apply two layers of 60# felt and asphalt mastic, followed by a 20mil polyethylene sheeting. Use asphalt-based coatings to seal any cracks or seams.
Install Ventilation System: Install a ventilation system with 4-inch diameter steel pipes (600 CFM capacity) and 200 mesh screens. Add charcoal filters to remove radioactive particles from the air.
Reinforce with Rebar and Steel Components: Embed rebar and steel components into the concrete to reinforce the structure. Ensure the steel components can withstand 10,000 psi stress.
Final Waterproofing: Use asphalt mastic and polyethylene sheeting to waterproof the interior of the shelter. This step ensures the shelter remains dry and structurally sound.

Conclusion

Building a fallout shelter requires careful planning and execution. Follow these steps to construct a safe and effective shelter that can protect you and your family in the event of a disaster. Remember to consult a licensed engineer for actual construction to ensure compliance with local building codes and safety standards.