A semi-analytical undrained solution for cylindrical cavity expansion in K₀-consolidated anisotropic soils under plane stress condition

Abstract

To remove the limitation that the plane stress problem cannot be considered using cylindrical cavity expansion and to explore surface response of cylinder expansion in shallow soil, a semi-analytical undrained solution is developed for cylindrical cavity expansion in anisotropic modified Cam-clay model soils under the plane stress condition. The constitutive relationship is described by the K₀-consolidated anisotropic modified Cam-clay (K₀-AMCC) model, which can properly simulate the mechanical behaviour of the K₀-consolidated natural clays. The problem is equivalent to solving ordinary differential equations to determine the effective stresses, vertical strain, and excess pore water pressure (EPWP). Parametric analyses are conducted to investigate the effective stresses, vertical strain, and EPWPs around the expanded cavity under plane stress condition. The results show a clear influence of over-consolidation ratio on the stresses, vertical strain, EPWP around the cavity, and effective stress paths for a soil particle at the cavity wall. Axial expansion or uplift of soil and negative pore water pressure are observed during cavity expansion under the plane stress condition. There are obvious differences in effective stress components around the cavity under two plane conditions. The effective axial stress around the cavity wall is generally smaller than that under the plane strain condition.

Keywords:

• Undrained solution
• anisotropy soil
• plane stress
• expansion response
• pore water pressure

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study is financially supported by the National Natural Science Foundation of China (U1934213), the National Natural Science Foundation of China (Grant No. 41602295), the Foundation for University Key Teacher by the Ministry of Education of Henan Province (Grant No.2020GGJS-094), the Key Scientific Research Projects of Colleges and Universities in Henan Province (Grant No.21A410002).