Analysis of modulus influence of axial zoned concrete-faced rockfill dam

Axial zoned concrete-faced rockfill dam (CFRD) divides the dam shell along the dam axis into bank slope area, transition area and central area. By filling different modulus materials in turn to form gradient modulus along the axis of the dam, the three-dimensional centralization deformation and the axial displacement of the dam shell can be reduced, which can improve the deformation compatibility of the dam body, thus the extrusion failure problem of high CFRD can be solved. According to the principle of face slab rupture of high CFRD, several reference indexes of face slab rupture problem (F-indexes) during the impoundment period were selected, including the deflection and the axial displacement of the face slab, and the compressive stress of the elevation near the maximum deflection of the face slab, the settlement and axial displacement of the dam body. Based on a 200 m level CFRD project, the F-index of axial zoned CFRD with 36 kinds of modulus gradient combinations was studied by numerical simulation. The effects of axial zoned CFRD design and modulus influence of axial zoned CFRD were analyzed. The results show that in 50% of gradient schemes, the axial displacement of the dam body decreases by 12.76% to the left bank and 14.73% to the right bank, and the settlement decreases by 14.42%. The deflection of the face slab decreases by 15.28%, and the extreme value of axial compressive stress of the face slab is reduced by 11.35%. The study provides a new idea for solving the problem of slab rupture of high CFRDs.