## Journal of Central South University

 第47卷    第8期    总第264期    2016年8月

[PDF全文下载]    [Flash在线阅读]

(1. 湖南省高速公路管理局，湖南 长沙，410001；
2. 中南大学 土木工程学院，湖南 长沙，410075
)

Dimensionless analysis of stress numerical stepwise procedure in strain-softening rock mass

1. Hunan Provincial Expressway Administration Bureau of Hunan Province, Changsha 410001, China;
2. School of Civil Engineering, Central South University, Changsha 410075, China

Abstract:Based on generalized Mohr-Coulomb failure criterion, an improved numerical method and stepwise procedure for the stress and displacement analysis of a circular opening excavated in a strain-softening rock mass were proposed by using the dimensionless analysis method. By deviding the plastic region of strain-softening rocks into finite annuli and calculating the stress and strain increments, the stress and displacement in the plastic region were obtained. The stress and displacement increments of the annulus were obtained through the stress equilibrium and compatibility equation of the annulus, and the stress and displacement of strain-softening region were obtained. The validity and reliability of the proposed solution were confirmed by the existing theoretical solution. The influence of partial parameters on the stress and displacement was revealed by numerical calculation and parameter analysis. The results show that the dimensionless solution is in agreement with the exact solution when the number of the annulus is enough. The plastic region decreases with the increase of the critical plastic strain deviation, and the plastic residual area vanishes when the critical plastic strain deviation increases to a certain definite value. The plastic radius and displacement increase with the decrease of the critical plastic strain deviation. The softened region turns into brittle when the softening control parameter is equal to zero.

Key words: strain-softening; numerical stepwise stress procedure; Mohr-Coulomb failure criterion; circular tunnel

 中南大学学报（自然科学版） ISSN 1672-7207 CN 43-1426/NZDXZAC 中南大学学报（英文版） ISSN 2095-2899 CN 43-1516/TBJCSTFT