2. CLASSIFICATION OF NEAR SURFACE CAVES

The cavities near the surface are divided into two groups according to their design: those with natural enclosure, ie without masonry, are called cavities; Both types are found in loamy loam soils and solid rock. The latter are characterized by the fact that their masonry is often hundreds of years old. Dangerous cavities on the surface may be shaped by their appearance - natural caverns - mine cuts - cavities formed during tunnel construction (eg metro) - artificial cavities, underground storage (built-in and carved cellars, storage) Natural caverns and caves in Hungary are protected by law. They are dangerous because their location is often unknown, and due to natural processes, their damage to the surface and possible rupture can occur unexpectedly. Such natural caves can be found, for example, in Budapest II. and III. perimeter. Investigating and remedying the damage caused by mine cuts is a special skill. Many settlements in Hungary are struggling with these problems. Unfortunately, it will take a long time for professionals to tackle the dangers of mining cuts, continuous slow field movement, or even a sudden, unexpected descent.

Building sinking over a mine cut

Surface damage management during tunnel construction is another profession, one of the most specialized in civil engineering. We had to deal with this problem in our country already in the 1950s, but it was really serious in the 1970s when the Budapest metro line 3 was built. By then many of the downtown buildings had collapsed, and the Deák Square Lutheran Church could only be rescued by immediate and significant intervention.

Budapest, Deák tér church

On this site I deal primarily with artificial (partly carved, to a lesser extent natural) caverns and cellars close to the surface, which were typically made in the old days by human labor and have become so critically neglected or neglected that they pose a threat to the surface. Their characteristic is that they extend below populated areas and that damage to the surface can therefore often lead to a major disaster ...