THE METRO CONTRUCTION DOES NOT JEOPARDIZE BUILDING „CH” OF THE TECHNICAL UNIVERSITY

The settlement of Building „CH” of the Technical University is lower than the threshold value expected by the experts based on the preliminary surveys. This statement has been confirmed by joint site visits of the parties carried out regularly since the start of the construction works. Settlement is the natural concomitant of civil engineering works carried out in the vicinity of old buildings and structures. In the case of the Technical University settlement has been reducing since the completion of work phases that impacted the building concerned, and subsidence has stabilized by now.

There were fractures and other symptoms indicating settlement revealed by survey conducted before the commencement of construction works, and construction obviously added to this impact. Nevertheless, this building is not jeopardized. Obviously the employer and the contractor will pay compensation for all damages caused by the construction of the 4th line of the metro such as cracks. These damages are less severe than expected.
The St. Gellért Square metro station is located under the Technical University Quay and Building „CH” of the University. Prior to the commencement of the metro construction the DBR carried out comprehensive surveys of the condition of buildings affected by the metro project, including geotechnical, geoengineering and hydrogeological expertises. The unambiguous conclusions made in the said reports concur in that Building „CH” of the University is classified as an object exposed to high risk; for this reason an independent structural analysis was carried out before bidding.
The bidders were aware of the above mentioned documents any they, including the winning bidder, submitted their respective bids and selected the technology of construction in the light of these reports. Prior to the commencement of works the winning bidder had to carry out an additional survey of the condition of this particularly endangered building, including the repeated structural survey. The preliminary and pre-construction surveys have both revealed cracks on the façade of the building, intensive moistening of the walls and crumbling of the mortar in various locations and poor condition of tile-covered walls. The surveys also reported on cracks along the corridor running in parallel with river Danube indicating settlement.
The DBR Metro Project Directorate invited various experts to review and evaluate the results of surveys conducted, including several distinguished professors of structural analysis and geoengineering at the Budapest University of Technology and Economics. The expertises concur in that the settlement / subsidence of the building is expected to remain below the level that would have required reinforcement prior to the commencement of the construction works. The construction works were began in this condition of the building. According to the preliminary survey the average settlement under Building „CH” was expected at 4.5 cm, and the maximum value of subsidence causing cracks of 2-3 mm width were expected as the result of subsidence.
Prior to the commencement of construction works the DBR installed the motion detector system, making Building „CH” the most intensively monitored site of the metro construction. The DBR also handed over the measurement results to the Operations Department of the Technical University. The contractor has been continuously recording the internal displacement of the tunnels.
The construction of load bearing structures of the station has been completed. At the time of the most recent joint site visit attended by the representatives of the DBR, the University, the contractor and by independent experts the maximum subsidence found was around 5 cm and the largest crack was 1.5 mm. The metro construction guidelines indicate crack damage of 5 mm width as minor. The settlement was found to attenuate which, by now, is quite close to stabilization.
The actual damage is less than the forecasted one and less than the crack limit stipulated in the contract. The survey revealed no damage that would indicate any deterioration of the structural stability of the building. Nevertheless, there are cracks on the side walls and the condition of mortar deteriorated, too; the tiling has also detached in the number of places, and therefore the DBR requested the installation of additional detectors. The DBR will also initiate negotiations on the damages cased by the metro construction, on sharing the costs in proportion to damages caused by the project and other issues regarding the measuring instruments for the detection / recording of vibration.
DBR Metro Project Directorate