Stability of the Cachtice Underground Corridors

At the beginning of the 16th century, the original inhabitants of Cachtice built a large complex of tunnels and cellars under the village, today called the Cachtice underground. The underground protected people from war conflicts, most recently during World War II, as anti-aircraft shelters. Over time, the underground lost its significance. The corridors were walled up, covered with rubble, and collapsed due to construction work. Later, a part of the underground was repaired, and historical events occurred in such a preserved part. Due to a lawsuit, the Cachtice underground was eventually closed to the public, and it was necessary to test the stability of the walls of the Cachtice underground. A 3D model of the underground was created, and three areas were identified in which numerical calculations were performed in Plaxis 2D software. The whole underground is located in loess soil. The Cachtice underground is stable if the conditions do not change diametrically. The calculated factors of safety support this assumption.