Case study: The Battle for Jezeří Chateau: Difference between revisions

The practical result was that, almost simultaneously, both the State Cultural Heritage Conservation and the general management of North Bohemian Mines commissioned Stavební geologie to perform a new, detailed, purpose-driven engineering geological survey of the Jezeří area. It was obvious beforehand that the survey was primarily meant to either confirm or refute his conclusions and interpretations made as part of the previous geological mapping. It was also evident that it would not succeed without unconventional and costly mining engineering methods, tunnels, shafts and deep core holes. It was not clear beforehand where to put them, what sizes to make them, who would design them, who would make them and how, and who would pay for them. A professional project design had to be made for each separate mining facility. In order to clarify those issues, Dr Marek spent the whole of 1977 making a detailed survey of the cellars and other underground spaces of the Jezeří Chateau grounds, and commissioned geophysical measurements in several points along the chateau buildings and the surrounding slopes where he had predicted the existence of tectonic fault zones. Only after that did he design subsequent, technically demanding works. He had his entire design reviewed by the most distinguished professionals, his old professors Quido Záruba and Vojtěch Mencl, the founders of the scientific discipline of engineering geology. They both came to Jezeří several times despite their advanced age of around 80 years.

A team of designers at Báňské projekty Teplice – the last ones who still knew how to design underground mining works in the North Bohemian Basin – were charged with drawing up the technical designs for the mining works. At the foot of the hill under the chateau, Dr Marek proposed a vertical shaft and two horizontal galleries under one another, dug towards the mountains; the bottom gallery was to be dug from the bottom of the shaft. Their purpose was to detect and cross the predicted tectonic fault zones. However, the mining engineers gave up on the job after a year spent designing it. There was no-one at hand who would be willing to carry out the designed work.

In the meantime, Jáchymov-based Výstavba dolů uranového průmyslu (VDUP – a uranium mining company) began digging a hydraulic tunnel in the mountainside above Jezeří to divert the Šramnický brook, and then another tunnel at Albrechtice to divert the Černický brook to the reservoir at Loupnice. Dr Marek and his team monitored the digging of both tunnels for over a year. They closely documented of the geological phenomena detected in depth within the crystalline complex to have enough background information for comparison for the planned survey under Jezeří. However, they were only able to do that at night, when the digging underground was halted for the day. To make even more work for themselves, they also took up documenting the new three-kilometre-long drainage tunnel in Jáchymov.

Thanks to co-operation with VDUP Jáchymov, they succeeded in convincing the company’s diggers to perform at least part of the planned mining work under Jezeří after the digging was completed. Most importantly, they managed to do the principal work: the horizontal gallery dug from the mountain base into the crystalline complex right under the chateau, 430 m long. They were documenting the gallery throughout the digging process; again, mostly at night. Deep core holes were bored in front of the gallery portal; an underground hole was bored inside the gallery, and an inclined core hole was bored under the chateau foundations. They documented all the rock formations around the chateau. They measured all the fissures, analysed the geodynamic phenomena and other facts. They found and documented the remains of medieval chambers for iron ore extraction and processing in old “salamander furnaces” discovered around the chateau. Dr Marek published the findings in the professional journal “Rudy” (“Ores”), which later resulted in their inclusion among protected national technical heritage sites.

The research around Jezeří took more than 4 years and was completed in 1981. It fully confirmed the findings and conclusions of the previous engineering geological mapping, which the North Bohemian Mines management would not accept in 1976. It confirmed the existence of massive tectonic fault zones at the mountain base and inside the massif, various anomalies in the positioning of the basin sediments along the seam edge and the groundwater conditions, and most importantly, it confirmed the unstable position of the promontory on which the chateau rests.