Research Cavern collapse and possible sinkhole development

The Tender Document at hand contains information regarding this invitation to tender conducted in accordance with the European open procedure for the following research: cavern collapse and possible sinkhole development. You are hereby invited to submit a Tender based on this Tender Document. # Reason for this invitation to tender SSM would like to gain better understanding of the consequences of a potential collapsing cavern. Although the chance of this happening is very small and difficult to quantify - the consequences can be very large. The Netherlands has over 250 relatively small - shallow caverns (mainly in Twente) and about 30 relatively large (0 - 5-5 mln m3) - deep caverns (in Groningen and Friesland) for salt mining and energy storage. A few cases of...