Earthquake

Why seismic tremor control is needed

Unlike the general image of earthquake, "collapse", we did not observe much damage to racks and rack-supported buildings that are designed in line with the safety and construction regulations. The major issues we observed are;

• Damage of stored loads due to fall-off from pallets
• Damage of material handling equipment due to fallen loads or pallets
• Difficulty of recovery work on collapsed loads at high position in the rack
• Collection and cleaning of goods scattered in the warehouse due to falls
• Loss from business interruption

To minimize such business risk, Daifuku sees it important to;

• Minimize rack sway
• Avoid load collapse from pallet
• Avoid pallet fall off from rack

Daifuku's seismic tremor control solutions

Business continuity planning (BCP) has become a must for companies that handle food, pharmaceuticals, and other products that must be provided even in an emergency. Daifuku offers varieties of seismic control solutions that can be applied alone or combined according to needs.

1. Stretch-wrapping & Binding

One of the effective ways to reduce the load turnover risk is to stabilize loads by stretch-wrapping or binding. Our experiments have shown that just wrapping the top of cases on a pallet has a certain effect when the entire surface wrapping is not possible due to operational reasons.

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  Stretch-wrapped pallet

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  Loads bound at the top

2. Fixed Stoppers at rack locations

The fixed stoppers installed in rack locations prevent pallets sliding into crane aisles during earthquakes. However, since the stoppers alone cannot prevent collapse of loads on pallets, they can be used in combination with stretch wrapping and binding to provide greater load stability. In addition, by attaching the stoppers with shock absorber and absorbing the shock when pallets and stoppers collide, the risk of load collapse on pallets can be further reduced.

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  Fixed stoppers are installed at each storage location to prevent protrusion into the crane aisle.

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  The stopper with shock-absorbing material absorbs the impact of collision between the pallet and stopper to prevent cargo collapse.

3. Quake-absorbing rack

The seismic damping components incorporated at the top of rack suppress the swaying by converting the collision energy to heat.

4. Seismically-isolated Rack

By making the AS/RS seismically isolated from the building, it will not be directly affected by the shaking of an earthquake. Since only the area where the automated warehouse is installed is seismically isolated, it can be installed at a lower cost than if the entire building were to be seismically isolated.

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  By installing the automated warehouse on the seismic isolation floor supported by the isolator (1), seismic force will not be transmitted to the automated warehouse. The oil damper (2) absorbs the seismic energy.

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  The damper at the top of rack converts the seismic energy to heat by repeating pulling and compressing.

5. Seismograph / Seismometer

When the seismograph detects a significant tremor, the equipment controller sends cycle stop signals to all equipment to reduce the potential for damage.

6. Optimizing storage location by load stability

Ordinary random storage management places pallets in any available location. This means that tall, unstable loads may be stored on higher levels where the impact of earthquakes is greater. With load stability information registered, WMS can limit location assignment for unstable loads to only lower levels, reducing the risk of loads falling during earthquakes.

Case Study

Nissin Pharmaceutical

Seismically isolated AS/RS strengthens steady supply of generic drugs.

• Japan
• GDP/HACCP
• Pharmaceutical