Seeing underground: the experience of searching with ground penetrating radar. Determination of voids in the earth How to search for voids in the earth with a sound blow

, Military expert "Stripes"

There is a strong but completely erroneous belief in the Israeli military-political establishment that there are no reliable technical methods for detecting underground tunnels, and therefore the main way is to visually identify them.

The author has collected extensive technical information that convincingly shows the existence and widespread use of highly efficient physical and geophysical methods for identifying various natural and artificial underground voids (karst formations, bunkers, tunnels, tunnels, etc.). Some of the information was obtained directly from specialists with extensive experience in this field, some from published materials. Below is a brief overview of the collected data.

A brief overview of attempts to solve the problem

Renowned geophysicist Professor Myron Rapoport, who now lives in the USA, believes that each of the methods of exploration geophysics (electrical, magnetic, gravitational and seismic, etc.) has the technical potential and resolution for detecting underground tunnels.

Note that in 1993 South Korea turned to prof. Rapoport, who lived in Russia at that time, with a request to identify North Korean tunnels crossing the demarcation zone using geophysics. His conclusion was as follows: the search for tunnels is a fairly simple task for geophysics. Unfortunately, the then political situation in Russia did not allow him to carry out this work.

We are told that back in 2004, the army considered a number of measures to combat arms smuggling through the tunnels from Egypt, and that almost every Israeli geologist was brought in to consider possible ideas on this issue.

This is not true

1. Dr. Yossi Langotsky, a well-known Israeli geologist, winner of the State Prize of Israel eight years ago sent his proposals to the ministers and high-ranking officers of the IDF to search for tunnels by geophysical methods. Its archive contains about 80 letters to several defense ministers and chiefs of the general staff that remained unanswered. But Langotsky, a retired IDF colonel, held responsible positions, incl. He was the Technology Security Advisor to the Secretary of Defense.

20 years ago, he proposed a method for detecting terrorist underground passages by installing special sensors along the border with Egypt to signal soil vibrations while digging tunnels. However, the Ministry of Defense considered this method imperfect. The military said that these sensors are only able to detect tunnels under construction, but are ineffective against already laid ones.

Then the MO decided that the best option would be the absence of both this and any other method. They returned to it only three years ago: the Elbit company took up the development of the tunnel detection system, but this happened after five Israeli soldiers died at the hands of Palestinian terrorists who had made their way into Israel in 2005, and in 2006 - m was kidnapped by Israeli Corporal Gilad Shalit.

At the end of May 2006, according to Haaretz's Amir Oren, "IDF engineering officers approached the Geophysical Institute. They expressed concern, suggesting that in the area of ​​the Sufa checkpoint on the border with the Gaza Strip, terrorists may be digging tunnels towards the Israeli border, both for short-term penetration and for the future. The officers asked the institute's experts to help identify tunnels that the IDF failed to identify.

The scientists expressed their readiness to provide assistance, but asked to make an official request, as it should be. The request was not followed, and Hamas militants carried out a successful operation against the IDF stronghold at the Sufa checkpoint.

2. Here is a letter received the other day from my colleague in San Francisco: “Recently I met with a scientist from Silicon Valley. He graduated from the Physics and Technology Institute in Moscow, was the head of the lab at the Academy of Sciences. Now in America, he is engaged in mathematical modeling (electromagnetic and seismic) in geophysics to decipher responses from underground structures, including both the search for oil, gas, water, minerals in the deep layers, and the search for near-surface voids (karst caves, tunnels).

He said the following: “Already a few years ago, we were able to adapt our models to find tunnels very efficiently. Realizing the importance of this for Israel, they sent through friends the justification of the method through several channels, including Sharansky, naively assuming that the Israeli government was not indifferent to such methods. However, no response was received at all. No one even asked for more information or arranged a meeting.” I told him something about the well-known Israeli bureaucracy, to which he replied that it was more like a parable about the tenth Jew.”

3. One more example. An alternative technique for finding tunnels was proposed by the construction contractor Doron Altar. In the early 2000s, he offered it to the Deputy Chief of the General Staff of the Israeli Army, Major General Dan Halutz.

According to Altar, Halutz did not even listen to him, saying that he was interested in "investing in planes and helicopters, not excavators." As Israeli journalist Pasit Rabin writes, similar disregard for proposals to combat "underground terrorism" was demonstrated by all military officials - from the former general director of the Ministry of Defense Amos Yaron to the head of the engineering service of the Southern District, General Moti Almoz. Currently, Almoz is the head of the army press service.

Who should set the task and coordinate the efforts of various institutions on this issue?

To coordinate work and develop tasks, there is a special structure - "Administration of Research, Development of Weapons and Technological Infrastructure MAFAT (Mafat - מפא"ת)".

IAFAT coordinates research and development programs on security issues for the Israeli Ministry of Defense, organizes cooperation between participants, including the IDF, the Ministry of Defense, various branches of the defense industry (Rafael, IAI, IMI, Elbit Systems, Institute for Biological Research), etc.
The head of the MAFAT is part of the General Staff ...

It must be admitted that in dealing with the most important problems, MAFAT cannot boast of effectiveness in the field of search and destruction of tunnels.

What has been done in the world today?

1. Tunnel detection in infrared

American satellites, equipped with special high-resolution infrared technology, see the tunnels. The fact is that the ground above the tunnel heats up and cools down more slowly, and therefore is visible in the IR range. The Americans reported that, according to their data from satellites, about 60 tunnels were revealed on the border between Israel and the Gaza Strip.

“Israel may be underestimating the number of tunnels on its southern border,” said Steven Emerson, an expert on national security, terrorism and “ Islamic extremism”, in an exclusive interview on 20.07 JPOST.

"This information," he said, "seems to contradict Israeli estimates of the remaining tunnels." Emerson suggested that Israel did not purchase this equipment due to the belief that the tunnels could be found without such equipment.

The American defense company Raytheon, one of America's top five defense contractors in the global defense electronics market, has won a tender to develop technology for detecting underground structures.

Laser system for detecting hidden tunnels and bunkers (photo: Raytheon Company)

The essence of the method is as follows. Explosions of special explosive devices are made on the surface of the area under study, and a remote laser meter measures the resulting low levels of vibration of the earth's surface. One laser vibration meter can simultaneously measure levels at 600 different points on the test surface. The received data are compared with the reference values ​​in the database. Based on the results of these calculations, a three-dimensional model is built, on which all underground voids, structures and equipment are shown with sufficient accuracy.

3. Solution from EnTech Engineering, Inc, St. Louis, MO, USA

EnTech Engineering offers equipment for underground diagnostics, including hidden tunnels.
Detection of underground tunnels begins with infrared analysis in suspicious places. Analysis systems detect specific energy patterns created by underground tunnels and other underground structures.

If suspicious areas are found, infrared examination for large areas can be supplemented with the help of "laser radars" (LIDAR). With this method it is possible to survey large areas in a short period of time (acquisition of data up to 100 linear kilometers of data per day) and mark areas requiring further study.

A more detailed study of the terrain can be made using a second generation microwave radar (GPR), which provides a three-dimensional image of the results.

EnTech Engineering offers to contact by e-mail for more information [email protected] or tel. 636-207-0200 .

The new development is called the Look-Ahead Sensor, or LAS. It locates bunkers and tunnels by measuring the echo emitted in response to sound waves. A device the size of a car steering wheel emits sound waves into the ground for about 8 seconds. Then special software processes the reflected signal. The presence of a tunnel causes a drop in the level of the reflected signal. "LAS is ideal for detecting tunnels and underground areas when used in the field," said laboratory engineer Phillip West.

6. Solution from IEEE

The IEEE, the world's largest association of technicians, considers radio frequency (RF) tomography to be the most promising field for detecting underground cavities, such as tunnels or shelters.

Tomography requires a set of inexpensive transmitters and receivers, placed randomly on the ground, or slightly recessed. Using the principles of backscattering and diffraction, tomography detects and localizes underground objects and hidden targets. The method is most suitable for conditions where the physical presence of a human operator is dangerous.

7. There are more solutions

The innovative company Geoscanners AB (Sweden) offers ground penetrating radars designed to search for mines, the location of underground tunnels, mines and warehouses. Good results are shown by complex devices using georadar and induction technologies, the so-called "METAL-RADAR". METALL-RADAR devices can be both portable and can be mounted on unmanned aircraft.

Kellyco of Florida offers the GPL 200 Soil Penetrator Locator. According to the company GPL 200 allows you to find caves or tunnels by electrometric methods.

A hand-held earth scanner has been created in Novosibirsk. It shines through the ground to a depth of 10 m. The image is three-dimensional. Small-scale production of this device, an electromagnetic scanner for deep sounding of the soil, has already begun at the pilot plant. Orders for 2009 came from Italy and China.” This was announced by Grigory Panin, the leading engineer of the development laboratory. 10 meters - the depth is insufficient, but the main thing is that the device works, and the viewing depth can be increased.

It is interesting to note that Egypt uses a radar scanner similar to the above to detect tunnels in the Rafah region and, I must say, finds it.

In addition, georadar (GPR - Ground Penetrating Radar) are used by Sensors & Software "s, Canada

In the United States, in some prisons, to prevent escapes through underground passages, sensor systems are used to listen to extraneous noises underground (which was suggested by Doron Altar to Dan Halutz). This technology is also used by North Korea to prevent escapes to South Korea.

What to do?

First of all - do not wait for the wonderful "Iron Dome" to search for tunnels in Gaza. Prof. Miron Rapoport emphasized that “comprehensive (of many different methods) and continuous year-round monitoring should be carried out. All observational results should be combined into a single computer database and constitute a kind of underground gas model, where all changes, all differences from the previous state of the model will have to be verified (compared with previous measurement data), ensuring reliability through a variety of independent detection methods. The received data will have to be analyzed, compared with human intelligence data and issued in the form of recommendations in real time to neutralize the threat.

Ensuring the transfer of information to the data processing center, creating and promptly updating a computer model of underground Gaza, all this is a big, serious job that requires sufficient costs, but obviously less than the Iron Dome. All the necessary theory has been developed, there are samples of equipment on the market, and there are specialists in Israel and other countries, primarily in South Korea. All that's left is to do it."

Conclusion

Many states are engaged in the problem of tunnel detection, there is a large scientific base and various technical solutions. Statements that "There is no guaranteed system for detecting tunnels in the world" are only suitable to justify one's own inaction and incompetence.

True, some are inactive, while others die. They must be held accountable for their deaths. Let's hope that after the completion of the active phase of the operation in Gaza, the existing system with the discovery of tunnels will become the subject of investigation by a special commission.

There is an urgent need to monitor the existence of underground tunnels in the Gaza border areas on the basis of equipment and technologies already available on the market, and in parallel to develop more advanced detection methods and devices.

There is no doubt that Israeli engineers will find the best solution to the tunnel problem. This decision will be of interest to many countries, where the US is first on the list.


The dowsing frame is currently widely used in various fields of human activity. With its help, they search for groundwater, voids in the soil, unfavorable energy zones (geopathogenic) and much more.

Meanwhile, the first mention of "dowsing", as dowsing was called in the old days (the name is still preserved in English), refers to 2100 BC. e. This is the opinion of the researcher of the phenomenon A. O. Krasavin. Later, in different centuries, the concept could be found in Pliny the Elder, Paracelsus, A. Mesmer. In the dictionary of V. Dahl, the phenomenon is described by the word "rhabdomancy", which means "search with the help of a wand for sources, places for digging a well, precious metals, treasures."

The dowsing effect has been used and is still being used especially widely in the waterless regions of India to search for sources of moisture. In China, they did not start building a house at all until the dowser was convinced that the building site was free from "deep demons."

According to the UN Special Adviser on Geology, Dutch Professor S. Tromp, people were engaged in dowsing 7,000 years ago.

From the ancient Egyptians to the present day, some mystery surrounds the movements of the "twig". And now - both the dowsing frame and the pendulum. Science seeks explanations for the unknown force in several directions. One of them proceeds from the assumption of the existence of radiation, in addition to electromagnetic and photon radiation, which characterize protein-nucleic life forms and are captured by a dowser with the help of a radar. Another approach is described by the well-known researcher of the mental sphere, Professor L.P. Grimak. He believes that the phenomenon of dowsing consists in “revealing actualized in the human mind and extrasensory perceived information in the form of ideomotor reactions. They are detected through the movements of dowsing indicators held in the hands - flexible twigs, wire frames, pendulums.

The practical applications of the dowsing effect are essentially limitless. In the north of Russia, the Saami of the Khibiny tundra have long used a twig to navigate the terrain, without a compass accurately determining the desired direction. Nowadays, operators from the Association of Engineering Dowsing, created by V. Pluzhnikov, have been successfully helping builders, geologists, rescuers and people in need of help for many years, finding water and minerals, missing people and lost things, underground voids with the help of dowsing frames. in cities.

And of course, with the help of dowsing, deviations in human health, the presence of unfavorable zones in an apartment or house, and extraneous energy-informational influence are determined.

So, what is a dowsing indicator? This is a special frame or pendulum. Frames are single-handed or two-handed (the interaction of two frames). Made of steel, aluminum, copper or brass wire, the frame can be L-shaped, additionally have a small lower bar at a right angle at the lower end of the handle or two equal bars at the top and bottom of the handle. The latter usually has a length of 9 to 12 centimeters, and the planks extending from it at a right angle are twice as long.

Usually, one frame is used for work, but much depends on the conditions of use of the biolocator. So, when working on the ground, when you need to explore an extended section of the surface, two frames are used to obtain a clearer result.

The operator holds the frame in a loosely compressed palm, while the arm is bent at the elbow. If there are two frames, they are held parallel to each other at a distance of 25-30 centimeters. As a result of energy-informational interaction with the object under study, an involuntary reaction of the operator's muscular system appears and the frame deviates from its original position. In this case, three types of movements are observed: rotation (inward or outward), rotation (clockwise or counterclockwise), vibrations, as a result of which the frame takes an unstable position that differs from the original one. If there are two frames, then they can cross, diverge to the sides or rotate.

Now - about the most important thing in working with a biolocator. By themselves, the movement of the frame does not mean anything. A certain code is needed, using which it would be possible to decipher the information obtained during the experiment. In other words, a mental contract is concluded with the frame, according to which each of its movements will mean a certain result. Most often, the "contract" takes the following form: turning the frame, say, inward will mean a positive answer to the question posed, and outward - a negative one. Unstable equilibrium - the absence of an answer to a question. In some cases, the strength of the reaction is also evaluated. The task of the biolocator can also be set in another form. For example, if you are looking for water in your summer cottage, the mental setting might be: "Let the frame turn outward when I pass over a place with a good underground source."

The so-called "witnesses" significantly increase the accuracy of the required forecasts. This word in dowsing is understood as material objects and mental manifestations that can better set up both the operator and the indicator for obtaining the result. Material objects include any items belonging to the wanted person, photographs or drawings that will be used to diagnose the disease, etc. Mental evidence is the operator's mental images associated with the object of research. They are created both as a result of personal communication with a specific person, and during a survey of third parties who were familiar with him.

Another ancient predictive tool is the pendulum. From time immemorial, it was considered a divine attribute, and those who knew how to use it were wise. There was a whole tradition of making pendulums. They were made in compliance with certain magical rituals, individually for the exact astrological indicators of the operator, and also taking into account his position in society.

The pendulum was brought to Europe from India by a professor at the University of Strasbourg Gerboin. Then, in 1799, the Paris Academy created a special commission to study the phenomenon of the pendulum, with the help of which the Indians successfully engaged in dowsing in search of groundwater, deposits of precious metals and stones. For some unknown reason, pundits made an unfavorable conclusion about the use of the pendulum, and interest in it was renewed only towards the end of the 19th century.

The essence of the phenomenon is similar to the effect of using a frame. Only in this case, the operator holds a small load on the suspension in his fingers. Spontaneous movements of the pendulum occur when a person concentrates on receiving certain information. They take the form of a weight rotating clockwise or counterclockwise. The body of a pendulum is usually spherical and weighs between 10 and 120 grams. In office conditions, a load of up to 30 grams is used, while a heavier pendulum is needed to work in open areas. The ball must be of correct shape and well balanced. The cord is made 8-10 centimeters long. It must ensure the free movement of the working body of the pendulum. Fluffy material is not allowed. The cord must not be black. You need to know that as the length of the cord increases, the sensitivity of the pendulum decreases. The same thing happens when the weight is too heavy.

The pendulum is usually held by the thumb and forefinger of the right hand. The upper phalanxes of the fingers are directed vertically downwards and form the anchor point of suspension.

The rest of the technique is the same as when using the frame. The “communication code” with the pendulum is also set and the reactions of movement in one direction or another are monitored.

Now, both in Russia and abroad, a lot of experience has been accumulated in dowsing in order to detect various objects, orientate in the area, and diagnose diseases. The techniques of such work are taught at the Russian School of Survival by the famous traveler Vitaly Sundakov. Modern dowsing is no longer a simple wandering around the area with a twig to determine the place of digging a well. In its study, the forces of the best physicists, psychologists-specialists in the field of the unconscious, highly qualified bioenergy therapists are concentrated. The scope of the method is unlimited, and who knows what new processes will soon be measured using a seemingly simple wire frame.

One of the negative engineering features of Moscow and the Moscow region is the predisposition of the local geological section to the emergence of karst cavities (underground void formations). Therefore, the determination of voids in the ground is one of the most important engineering and geological tasks that our company successfully solves.

Why is the definition of voids in the ground necessary?

Within the territory, which occupies approximately ten to twenty percent of the total area of ​​the Moscow region, construction is associated with the risk of sinkholes, which are formed due to the appearance of voids underground and can lead to the collapse of objects under construction or already commissioned. This danger is further increased under the influence of additional factors:

    an increase in natural seismic activity, recorded in recent years;

    high technogenic vibration load on soils;

    a large number of leaks from water supply and sewer communications (some of which are difficult to detect in a timely manner);

    rising groundwater levels.

Thanks to many years of exploration experience, the GeoGIS company accurately determines karst voids in the soil on the studied land plots and can give reasonable recommendations to prevent possible risks for the planned construction.

With what equipment and how to find the void underground?

Karst processes have long been comprehensively studied by engineering geology. As a result of many years of research, practical recommendations have been developed that facilitate the determination of voids in the ground; various devices have been invented and tested for this purpose. Our company has devoted a long time to a deep study of this issue, and now we can confidently guarantee that the survey methods used by our GeoGIS company are among the most effective. We search for voids underground during engineering and geological surveys using modern geophysical equipment:

    equipment for vertical electrical sounding and profiling of soil sections;

    devices for radio wave transillumination of geological horizons (ground penetrating radars);

    installations of seismic geological exploration.

Geodetic methods for determining karst voids in the ground, which we use, are based on significant differences between karst zones and the surrounding rocks in a number of physical indicators:

    specific electrical resistance;

    ability to absorb and reflect radio waves of certain ranges;

    the rate of transmission of elastic vibrations.

Important! The size of the geophysical anomaly above the areas of soil affected by karst directly depends on the size of the karst cavities and the depth of their location.

What are voids underground?

The complexity of the problem - how to find a void underground - is determined not only by the size of the karst cavity and the depth of its localization, but also by the conditions of occurrence of rocks in the study area. Underground voids can be represented by three types of karst, each of which has features that determine the form of its external manifestation and search methods during survey work:

    Open karst. Karst rocks lie directly under the soil layer. In this case, the search for voids underground is the simplest and does not require the use of a set of methods by our specialists. Electrical exploration alone is quite enough. The voids are easily contoured, and it is not difficult to determine the degree of fracture of the rock, the saturation of the voids with water. Karst formations can also be identified by external features of the terrain.

    Karst topped with permeable soils. The task - how to find a void underground - is greatly complicated by loose cover deposits (sands, light sandy loams). Knowledge of the principles of moisture distribution at the boundary of cover soils and karst zones helps us to identify underground voids in such conditions. A good search criterion (for an experienced observer) is a change in the water cut of the upper soil layer, accompanied by a corresponding change in its physical properties.

Increasingly, houses made in a monolithic way are becoming more common. Yes, and in private homes, the monolith is replacing concrete slabs

overlap. Yes, the method gives increased strength. Nobody argues. But…

- the advertising slogan of one of the firms sounds. How to believe? Rather, do not believe, but it is necessary to check. After all, when pouring concrete, a number of flaws can occur. Moreover, if some of the defects can only affect the appearance and they are removed in a cosmetic way. Then some defects are not amenable to visual inspection, while significantly affecting the strength of the structure, and in some cases directly threatening safety.

One of the types of such defects is the formation of voids in the thickness of concrete. Voids are formed due to the failure of concrete to pass in some separate area. Moreover, sometimes voids can be of such dimensions that it is possible to expose reinforcement or even through voids. Which cannot but affect the strength of the monolith.

In some cases, voids can be identified by tapping the monolith with a hammer. In places of voids, the sound will be noticeably muffled. But, as a rule, it is used on small objects and small thicknesses of the monolith. Plus, voids can be detected if they are fairly close to the surface.

What to do if the thickness of the monolith differs fairly and / or the voids are located quite deep? In these cases, non-destructive testing devices (NC) are used. Ultrasound is mainly used for this purpose. Ultrasound is most suitable for end-to-end inspection. Device UK 1401. Quite easy to use, designed for both surface and through scanning of concrete. Gives a great picture. Through IR ports can transfer the image to the computer.

After voids are found, this defect should be immediately eliminated. To do this, the surface of the voids is cleaned from old loose concrete, washed with water. Fill the voids with concrete with a fine fraction, with careful vibration. To accelerate the maturation of concrete, steam and electric heating of the pouring place is used. In winter, it is recommended to use infrared lamps before and after pouring. When sealing voids, the presence of a laboratory assistant and foreman is mandatory. They check the thoroughness of the termination by vibrating or bayoneting.

Price: from 100 rubles/p.m.

To have full information about the site - its relief, hydrological conditions, geophysical characteristics (features and structure of the soil), means, with minimal time and finances, to carry out (or start) the necessary work. The geologists of our enterprise "Surveys of the MSC" carry out qualitative and qualified studies of the soil. We also solve more specific tasks, such as determining voids in the ground, searching for metal and non-metal pipelines, and searching for water veins.

Determination of voids in the ground of various origins is an important task

Cavities under the soil layer can occur for various reasons. Let's consider the most common.

  • Karst processes (washout and dissolution of limestone rocks by groundwater) caused the appearance of voids, a considerable part of which are found today in cities, often in built-up areas. To miss such an important feature of the territory means to expose the object to the danger of failures, subsidence and destruction. Turning to the services of specialists in time who know how to find a void in the ground means preventing deformation and destruction of the structure.
  • Voids underground can be formed as a result of man-made accidents. Failure to comply with pipeline laying technologies causes gusts and leaks that wash out cavities underground, asphalt or concrete pavement.
  • The determination of voids in the ground is also carried out by our specialists in the places of ancient buildings, where the ancient cultural layer is hidden under the earth and modern buildings. Old basements, cellars, which are not on any map of the city, can become an unpleasant "surprise" for the developer or owner of the site.

When is the determination of voids in the ground ordered?

from 100 rubles/p.m.

The most common goal pursued by the Customer, having ordered the search for underground voids in our company, is to protect future construction from landslide processes, the appearance of failures and subsidence of the soil. To do this, we conduct geological surveys, which include the determination of cavities in the soil. We also carry out the search for voids purposefully, without reference to complex studies.

Often, the determination of karst voids in the ground by our specialists occurs at the request of the Customer for an object in operation, when damage to structures, distortions of openings and cracks clearly indicate problems with the foundation or base of the building (structure).

ATTENTION! Timely detection of the problem, namely voids in the ground, and taking radical measures to eliminate it in terms of money will be much more profitable than saving the structure in emergency mode.

Our specialists also work on the orders of archaeologists, historical search expeditions, speleologists, whose workers do not have the necessary equipment and skills.

Photo 1. Determination of voids in the ground in Moscow and the region

How to find the void underground?

Each research work requires not only theoretical knowledge and great effort, the quality of research largely depends on the professionalism of our employees, who know from their own experience how to find the void underground. Using many years of research skills, we find cavities with great accuracy, using specialized instruments and techniques for studying the earth's depths:

  • devices, the principle of operation of which is to emit their own and receive reflected electromagnetic impulses;
  • seismoacoustic method;
  • using the principle of electrical resistance (vertical electrical sounding).

A modern high-resolution ground penetrating radar for subsurface radar sounding makes it possible to transmit continuous data about the studied profile to the receiving device. After being converted into a digital form and processed by special programs, the computer gives our specialists a detailed “picture” of the soil section:

  • the depth of the location of the void formation;
  • dimensions of the cavity in plan and vertical.
ATTENTION! We obtain accurate data by examining the earth's thickness up to 30 meters deep.

You can learn more about the service from our specialists using the feedback on the website or by calling our company.

 

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