Test study on dynamic deformation behavior of soft rock-concrete sample under cyclic loading

Considering three contact states of good contact, containing weak interlayer and water, containing weak interlayer but no water, a series of cyclic triaxial compression tests of soft rock-concrete samples for investigation the dynamic deformation behaviors are carried out. The influence of contact states on dynamic properties of combination samples is analyzed based on the dynamic stress-strain curves and accumulative strain curves. The results show that changing the contact states has notable effects on the dynamic strain of the samples. Comparing with the good contact sample, the accumulative strain of the sample containing weak interlayer is about 2 times. The amplitude of the sample vibration increases, while the accumulative strain reduces with the increase of the vibration frequency. It can be noted that the measures such as assuring construction quality, removing weak interlayer and water, keeping good contact state between bedrock and tunnel structure can reduce the settlements and improve the tunnel service life.