Physical investigation on the behaviours of voussoir beams

It is important to understand the behaviour of voussoir beams in the design of underground excavations.There are a large number of discrepancies between the re sults obtained by differe nt researchers so far.To resolve these discrepancies,physically testing the stress distribution at the mid span and abutment of voussoir beam is the key.In this paper,a simple two-block voussoir beam was built with loading system.The displacement and strain of the voussoir beam were measured by a digital image correlation system.The strain distribution along the joints of voussoir beams was firstly revealed.Then,the relationship between transverse load and midspan displacement of voussoir beam was presented.It is found that the stress distributions at the midspan and abutment are different both in shape and depth.The stress distribution is changing as the loading changes as well.