Sandbag

Sand bags are used both for flood control and dike defense, as well as to the construction of simple dwellings or entire building complexes. One can use them to build sandbag dikes, increase existing dikes, dike foot - backups, build source Kaden or protect buildings. Sandbags are also used in the military field. There they serve as cover against shrapnel and bullet holes. Compared to a fixed coverage, they have the advantage that there is no Abprallschüsse. Sandbag dams can also be used to collect contaminated water used for extinguishing.

Statics

Walls or barriers of sandbags are in principle subject to the laws of gravity walls. You can very reach great heights, but are always wider at the bottom than execute above. The stronger tendency should thereby on the side facing the water are to exploit their own weight to stabilize. However, it is logistically hardly feasible to build large structures made ​​of sandbags, even if it is technically possible. Due to the dynamic load sandbags are as flood protection at sea less common than in rivers.

Material

Sand bags are made of natural fibers (eg, jute) or plastic (eg polypropylene). For flood protection they are filled to 2 /3 full with sand. Bags, plastic, have the disadvantage that they slip much lighter than natural fiber bags. Come natural fiber bags in contact with water, they soak and swell. Thus, the sandbag dike is additionally sealed. In addition, the decay of natural fibers when bags are left in the dike or were swept away by the river.

Plastic bags are preferable when filled bags should be stored on storage a long time. This is regularly the case with dike protection organizations in flood-prone areas.

Usually the bags are sealed with tape or tie wire. But they can also sew with special bag sewing machines. This has the advantage of a more rigid closure sheeting better and safer and more efficient transportation. When the time for closing does not exist, but they can also be used openly. The opening is folded and placed under the bag. The weight of the sand is so on the opening. When fitting the bags is also making sure that there are no gaps. To achieve this, the lying sacks are trodden by foot.

Filling

The filling of the sandbags can be completely manually but also done by machine with a Sandsackfüllmaschine.

Improvised sandbag filling ( Upside down traffic cone )

Manual filling of sandbags with a sand silo

Manual filling with conveyor belt and 10 - port manifold

Ro Sandsackfüllmaschine ( AB SaSaFü )

Transportation of sandbags in flood

The transport of the filled bags to the operation site can usually not be carried out completely by truck, boat or helicopter. This is due to soggy dikes or impassable bridges. Therefore, the transport to the installation site is done almost exclusively via a human chain.

The helpers only sees some distance towards ( zipper). The distance should be chosen so that the sandbags are comfortable enough without being moved. Sandbags should not be thrown, as this is too exhausting to be permanent and can lead to injury if the scavenging helper is not ready yet.

Application

When building a sandbag dike must be taken with each other primarily on a tight bond and a clean installation technique of sandbags. This will ensure that a waterproof and stable dam created.

• A bag of sand at the foot is moved along the water
• In the second position the sandbags are laid across
• Width at least equal to twice the height

Alternative systems

From various providers Quick dike systems are offered.

As a substitute and supplement for sand bags big bags (usually 1 m ) are used. These have the advantage that in any future transportation by helicopter or wheel loader rapid deployment is possible. Especially with a complete dike breach can be a first aid. For an increase of an existing dam these are due to the high cost of transport used rarely. The high individual mass is advantageous in emergency situations these great bags are used when the installation of small sandbags is no longer possible.

Use for house building

The German architect Gernot Minke developed was a design concept, were used in the pumice -filled sandbags to build load-bearing walls. He is director of the Research Laboratory for Experimental Building at Kassel University.

The Iranian architect Nader Khalili developed the so-called Earthbag architecture, which filled with soil and other materials sandbags are used primarily for the construction of houses in the Third World. He is the founder of the Cal - Earth Institute in California, which deals with the dissemination and advancement of this technology.