基于三维随机场的地下洞室围岩变形分析

为充分考虑材料的非均匀性以及各向异性，将岩土参数模拟为三维随机场，分析岩土体参数的空间变异性对围岩变形的影响。采用Ｋ－Ｌ级数展开方法生成弹性模量的三维随机场，构建了考虑弹性模量空间变异性的有限差分模型，研究了不同横向、纵向、竖向波动范围对开挖区域上覆岩层变形的影响。研究结果表明:在竖向波动范围小于0．4ｍ时，地下洞室围岩的变形值不会发生较大的改变；相对于横向和纵向波动范围，竖向波动范围对位移的敏感性更大，且波动范围越大，位移值相对于确定性分析结果的变化越明显。弹性模量的空间变异性对围岩变形有着重要的影响，洞室轴线位置处的变形受其影响更大。

Deformation Analysis of Underground Cavern Based on 3D Random Field

The excavation of underground caverns will cause regional deformation,therefore,construction of underground structure requires a reasonable estimation of deformation of surrounding rocks.Aimed at considering the heterogeneity and anisotropy of materials,the geotechnical parameters are simulated as 3D random fields,and studying the spatial variability of geotechnical parameters on deformation of surrounding rock,the Karhunen-Loeve(K-L)expansion method is used to generate random field of Young’s modulus,the finite difference model considering the spatial variability of parameters is developed.The effects of scales of fluctuation of Young’s modulus in transverse,longitudinal and vertical directions on the surrounding soil deformation are discussed in detail.Results show that the surrounding soil deformation value varies less when the scale of fluctuation of Young’s modulus in vertical is less than 0.4m.Scale of fluctuation in vertical is more sensitive to displacement than other two directions.With the increase scale of fluctuation,the displacement value changes more obviously compared to the deterministic result.The spatial variability of Young’s modulus has an important impact on the deformation of surrounding rock,and the influence of spatial variability on the mid span position is greater.