Abstract: In this article, a test rig applying to research on the vertical interaction between deep soil and shaft lining has been developed successfully. Vertical interaction test between saturated sand and C60 concrete shaft lining has been studied preliminarily. The test rig has three main technical parameters: the maximum effective test space is 820 mm×820 mm, the maximum pressure capacity is 24 MPa and the maximum depth of research soil is 1 200 m. The vertical shear test between saturated sand and C60 concrete interface shows that when the average interface normal stress is 0.2-0.4 MPa, the shear stress-shear displacement curve can be described by elastic-plastic model. The maximum shear displacement is about 0.53-1.11 mm. The ultimate static friction coefficient is 0.70-0.53 and the interface shear strength is 140-210 kPa.

Key words: deep soil and shaft lining, interface interaction, high pressure test rig, numerical simulation, experimental analysis