Editor | On 06, Oct 2008

By Abram Teplitskiy

The author worked in the Ukraine in the construction industry, initially developing tools for testing the quality of soil compaction. During this time, the Ukraine was home to an increased volume of reconstructive construction works and a laboratory of reconstruction was “attached” to the author’s laboratory.

Electro-hydraulic Effects

One of the initial challenges in this area was the destruction of large stones, pieces of structures, hard soil monoliths, etc. to begin construction. It was necessary to develop new destruction methods, some of which were based on serendipity. Well-known Moscow scientist and engineer Mikhail Khasin tells the following story: A friend, a teacher, was actively making different radio devices at home. The friend combined the making of the devices with eating. Occasionally two ends of electrical scheme got in a bowl of his soup. As a result, the soup became a heap of fragments. Being an inventor (in addition to a teacher), this man thought about how to use this sporadically achieved effect; the answer was a new construction technology tool – electro-hydraulic effect.

Russian Federation Patent #2,163,295, “Methods of Electro-hydraulically Destroying Solid Bodieselectro-hydraulic” shows electrohydraulic destruction of solid bodies (matter) by boring holes in stone-like materials, filling the holes with water, conveying them some distance and putting electrodes in the holes to provide electrical discharge impulses. (Figure 1) Each such shock wave includes pre-determined time intervals between pulses.

Figure 1: Electro-hydraulic Effect Russian Federation Patent #2,163,295

The result of electro-hydraulic electrohydraulic effect is the destruction of the material by shock discharges; the material is impacted by time impulses. The technical effect of this process is the splitting of stones into smaller pieces. Not only does this clear the way for new construction, but the resulting fragments can also be used for this – or other – new construction.

Wedge

The simplest tool for destroying monolithic structures is a wedge, which people have used for solving different problems since prehistoric times. For this purpose, blast holes should be drilled in the large monolithic material, which should be filled with a mixture of a non-Newtonian liquid (for example, a mixture of clay with used grease – a lubricant) and loose material. Wedges can be placed in the mixture, resulting in their cracking and splitting.

The simplest tool for destroying monolithic structures is a wedge, which people have used for solving different problems since prehistoric times. For this purpose, blast holes should be drilled in the large monolithic material, which should be filled with a mixture of a non-Newtonian liquid (for example, a mixture of clay with used grease – a lubricant) and loose material. Wedges can be placed in the mixture, resulting in their cracking and splitting under the wedging force. (Figure 2)

Figure 2: Wedge System 1 – monolithic material; 2 – mixture of clay with grease lubricant;3 – granular soil; 4 – different materials Russian Federation Patent #2,131,032

Another technological option for destroying monolithic construction materials is based on the application of explosive materials (Russian Federation Patent #2,300,730). A device contains explosive materials in a shell or casing of elongated form with metal. In a separate groove, metal foil and a blast initiator are placed. This invention allows for an increased effectiveness of destroying monolithic materials using less explosive materials – due to the careful placement of the components.

Modeling the Destruction of Monolithic Materials

It is desirable to model the process of destroying monolithic materials. The author, along with a group of Ukrainian specialists, developed a special stand that is shown in Figure 3.

Figure 3: Stand for DeterminingForces Acting in Blast Hole SU Patent #1,745,928

This stand, used to determine the forces acting inside a blast hole, include a power-disassembled frame (body) in which a force sensor-transmitter is placed. To develop an adequate model, a sample of the material to be destroyed should be placed in a heavy-duty holder.

Summary

These new, inventive methods for destroying construction materials have proved useful in the Ukraine and should be useful in other locations as well.