Publication details
Implementation of geological exploration works in the environment of rocks mass with strong tectonics disturbance in the area of Červený vrch/Bořislavka station on the new metro line V.A in Prague
| Authors | |
|---|---|
| Year of publication | 2013 |
| Type | Article in Proceedings |
| Conference | 12th International Conference Underground construction Prague 2013, Proceedings |
| MU Faculty or unit | |
| Citation | |
| Field | Geology and mineralogy |
| Keywords | underground construction; geotechnics; geological exploration |
| Description | Červený Vrch/Bořislavka station is located on the new metro line V.A in Prague and was designed as one-vault mined station with a length of 193 m and cross section about 224 m2. The station with a total overburden of 15 - 22 m is situated under a busy street Evropská with central tram lane and many high buildings in close surrounding. In a short time before the scheduled start of the excava-tion additional exploration works in the area of the station were carried out. These exploration works, together with the results of the access adit geological mapping, discovered diametrically different geo-logical conditions than originally anticipated. Instead of the expected massive quartzites throughout the area of the station an occurrence of shales of varying degree of weathering and intensive tectonic disturbance with only rare quartzite layers was found out. Newly detected significantly less favourable geotechnical conditions led to a need to modify the project to ensure the stability of the underground excavation, to adaptation of excavation process and design of a number of other construction-technical measures. Evaluation of the results of comprehensive geotechnical monitoring and geological mapping of progressive excavation of the station enabled retrospectively evaluate the findings of the exploratory works in the form of structure-geological model of the rock mass and determination of its geotechnical parameters. The issue of project preparation and excavation process of Červený Vrch/Bořislavka sta-tion well illustrates the need to follow the basic rules for implementing of geological exploration works, especially to perform surveys in several successive stages in an adequate scale and sufficiently in ad-vance before the start of the construction. |