基于GPU加速随机场的洞室变形破坏特征研究

Deformation and Failure Charateristics of Tunnel Excavation Based on GPU Accelerated Random Field

洞室围岩参数一般具有很强的空间变异性,本文研究了岩体参数随机空间分布对围岩稳定性的影响。提出了基于协方差矩阵分解和GPU加速的空间随机场生成方法,建立将随机场与高级应变软化模型参数的映射,对比不同条件下随机场的变化以及对后续模拟开挖的影响。结果表明:指数型相关函数生成的随机场较为稳定分散,其最大位移值变化范围较小;平方指数型相关函数生成的随机场更为紧凑,最大位移值波动范围较大,偶然出现较危险的位移;对比X,Y相关长度可以发现,最大位移点的分布是相似的,开挖过程中洞室两侧中部、底部和拱顶是危险区域,损伤位置主要集中在洞室侧墙、拱顶交接处和侧墙中部。

The random distribution of parameter of the surrounding rock have obvious effect on the stability and this paper investigates the influence of the random spatial distribution of rock mass parameters on the stability of surrounding rock.A random field generation method based on the covariance matrix decomposition and GPU acceleration method is proposed.A function that transforms the random field to IMASS constitutive model parameter were successfully established.Afterwards,the effect of the random field under different conditions and the influence on the subsequent simulated excavation were compared.The results show that the random field generated by the Exp correlation function is relatively stable and scattered,and its maximum displacement value varies within a small range;the random field generated by the SExp correlation function is more compact,with a larger fluctuation range of the maximum displacement value,and more dangerous displacements occur occasionally.It can be found from the X,Y correlation length that the distribution of the maximum displacement points is similar.During excavation,the middle,bottom and vault on both sides of the chamber are dangerous areas,and the damage locations are mainly concentrated in the cavern side wall,the junction of the vault and the middle of the side wall.