基于扩孔理论的劈裂注浆启劈压力解析
Analysis of Critical Fracturing Pressure of Splitting Grouting Based on the Cavity Expansion Theory
何欢 1寇磊1
作者信息
- 1. 郑州大学水利与交通学院,郑州 450001
- 折叠
摘要
基于圆孔扩张理论,结合SMP(spatially mobilized plane)强度准则与临界状态概念,将变换应力后的张量应用于能描述软黏土各向异性的Wheeler模型,对劈裂注浆中球孔扩张问题进行了分析.采用双区间分析模型将土体分为弹性区和塑性区,通过弹塑性区间边界条件,推导了孔周土体的应力应变场和位移场,对劈裂注浆后的土体扩张半径、启劈压力及塑性体应变进行理论计算,并以算例进行了论证.结果表明:径向有效应力和环向有效应力随着参数r/rp的增大而减小;劈裂注浆的启劈压力随着内摩擦角数值的增大呈现上涨趋势;内摩擦角是土体进行弹塑性分析时的一个重要影响因素,当内摩擦角越大时,塑性环向应变、塑性区半径、塑性区位移越小,启劈压力越大.
Abstract
Based on the spherical cavity expansion theory,combined with the spatially mobilized plane(SMP)criterion and the critical state concept,the Wheeler model describing the anisotropy of soft clay was applied to analyze the spherical cavity expansion problem in split grouting.A dual interval analysis model was used to di-vide the soil into elastic and plastic zones,and the stress-strain and displacement fields of the soil around the cavity were derived under the elastic-plastic interval boundary conditions.Theoretical calculations of the soil expansion radius,the critical fracturing pressure,and the plastic volumetric strain after split grouting were car-ried out and demonstrated by several examples.The results show that,the radial and circumferential stresses decrease with parameter r/rp;the critical fracturing pressure increases with the internal friction angle;the inter-nal friction angle is an important influential factor in the elastic-plastic analysis of the soil,and the larger the in-ternal friction angle is,the smaller the plastic circumferential strain,the plastic radius and the plastic displace-ment,and the larger the splitting pressure,will be.
关键词
启劈压力/Wheeler模型/SMP强度准则/球孔扩张Key words
critical fracturing pressure/Wheeler model/SMP criterion/spherical cavity expansion引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据