Definition

An underground bunker is a specially constructed subterranean structure designed to protect personnel, supplies, or equipment from external threats, such as artillery attacks in warfare or natural disasters. By leveraging the natural protective properties of underground soil layers, it provides a relatively safe environment inside.

Structural Features

• ​Robust Construction Materials: Typically built using high strength materials such as reinforced concrete and steel for walls and ceilings to withstand external impacts and pressure. For example, thick reinforced concrete walls can effectively disperse and absorb energy from bomb explosions, ensuring the safety of the bunker is interior.
• ​Rational Space Layout: The interior is designed according to its intended use, potentially including living quarters, storage areas, and equipment zones. Living quarters are equipped with basic amenities like beds, tables, and chairs to accommodate prolonged stays; storage areas hold supplies such as food, water, and medicine; and equipment zones house critical systems like power generators and ventilation units to maintain bunker operations.
• ​Excellent Sealing: To prevent the ingress of toxic gases, radioactive substances, and other hazards, underground bunkers feature superior sealing. Doors and windows use specialized sealing materials to ensure effective isolation from harmful external elements in emergencies.

Functional Uses

• ​Military Defense: During wartime, underground bunkers serve as vital defensive installations for military forces. Soldiers can take shelter from artillery fire, airstrikes, and other attacks, while bunkers may also function as command centers or ammunition depots. For instance, some military bunkers are equipped with advanced communication systems, allowing commanders to direct operations from within.
• ​Disaster Shelter: In the event of natural disasters such as earthquakes, hurricanes, or volcanic eruptions, underground bunkers provide a safe refuge. They can withstand seismic shocks, hurricane force winds, and other hazards, safeguarding lives. Additionally, in incidents like nuclear radiation leaks, bunkers can serve as temporary protective spaces to minimize radiation exposure.
• ​Material Storage: For critical supplies such as cultural relics or strategic reserves, underground bunkers offer a stable storage environment. The relatively constant temperature and humidity underground help mitigate external environmental factors, extending the preservation period of stored items.

Construction Requirements

• ​Site Selection: Locations must have stable geological conditions, higher elevation, and good drainage. Avoid areas prone to landslides, mudflows, or high groundwater levels to ensure the bunkeris safety and stability.
• ​Ventilation and Drainage Systems: A reliable ventilation system is essential for maintaining fresh air and occupant health. Ventilation ducts and equipment introduce fresh air while expelling stale air. Meanwhile, a well designed drainage system prevents rainwater and groundwater infiltration, avoiding issues like flooding and dampness.
• ​Emergency Exits: At least two secure exits must be provided to ensure rapid evacuation in emergencies. Exits should remain unobstructed and be equipped with emergency lighting and directional signage.