Triple-shear Unified Solutions of Plastic Displacement for a Deep Circular Hydraulic Tunnel(PDF)
《建筑科学与工程学报》[ISSN:1673-2049/CN:61-1442/TU]
- Issue:
- 2017年06期
- Page:
- 11-20
- Research Field:
- Publishing date:
Info
- Title:
- Triple-shear Unified Solutions of Plastic Displacement for a Deep Circular Hydraulic Tunnel
- Author(s):
- ZHAO Jun-hai; LU Mei-tong; ZHANG Chang-guang; JIANG Zhi-lin
- School of Civil Engineering, Chang’an University
- Keywords:
- deep circular hydraulic tunnel; intermediate principal stress; radius-dependent elastic modulus; brittle softening; shear dilation characteristic
- PACS:
- -
- DOI:
- -
- Abstract:
- Based on the triple-shear unified failure criterion and the elastic-brittle-plastic model, taking the integrated influences of intermediate principal stress, seepage, shear dilation, softening, elastic modulus of plastic zone into account, the analytical solution of plastic zone displacement of hydraulic tunnel with 5 factors was deduced. Through example analysis, the influence law of each parameter on the plastic zone displacement of tunnel was obtained. The results show that the analytical solution has wide applicability and can be degenerated into a series of solutions when the parameters are different, the parameter values can be rationally chosen according to the specific project. The shear dilation characteristics of surrounding rock have significant influence on the displacement of plastic zone in tunnel, without considering the influences, the deformation of tunnel will be underestimated obviously, so that the engineering design will be dangerous. Considering the influences of intermediate principal stress, the potential strength of surrounding rock can be brought into play, the support can be reduced, and the engineering cost can be saved. Considering the influence of seepage and softening characteristics on the radius of plastic zone, the plastic zone can be closer to the true deformation range of surrounding rock. The elastic modulus of plastic zone can be fully considered by the expression of radius power function, the stress redistribution and blasting damage can be fully considered after the disturbed degradation of surrounding rock, and the results are more in line with the true deformation of tunnel. The displacement solution provides a theoretical basis for the displacement calculation of the plastic zone in the tunnel, and has a certain reference value for the engineering design.
Last Update: 2017-11-30