Abstract
To clarify the deformation behavior of an irrigation tunnel with a void behind its lining, a model experiment applying vertical load was performed. The test specimens consisted of lining, peripheral ground, and several ranges of voids behind the lining. The lining was made of mortar and peripheral ground around the tunnel lining was made of low-strength mortar. Stress on the lining and the deformation of the inner section were measured, and the movement of peripheral ground was analyzed by the digital image correlation method. When there was no void, or the void was in the range of 45 degrees, the lining was deformed in the vertical direction. Whereas, in a case where the range of the void was 90 degrees, the peripheral ground moved into the tunnel as the deformation progressed, resulting in the inner section being expanded in the vertical direction and reduced in the horizontal direction.
