(浙江大学 岩土工程研究所， 杭州 310027)
摘 要: 在考虑材料剪胀性和塑性区弹性变形的情况下，研究了塑性区中弹、塑性变形情况以及对应力场、位移场的影响。研究表明剪胀角ψ和内摩擦角φ对弹塑性交界处半径R有显著影响；给出了塑性区中平均体积应变及弹、塑性变形体积的计算公式和剪胀角的测试方法。 通过算例研究发现，弹塑性交界处半径R随着剪胀角ψ的增大而逐渐减 小，塑性区平均体积应变却随着剪胀角ψ的增大而增大。研究表明塑性区中弹性变形部分忽略是不合理的。
关键字: 剪胀性；球形空腔扩张；弹塑性分析
cavity expansion with consideration
of material dilatancy
（Institute of Geotechnical Engineering，
Zhejiang University，Hanghzou 310027，China）
Abstract:Elastic and plastic deformations in the plastic zone and their effects on stress and displacement fields were investigated with consideration of material dilatancy. It is shown that the angles of dilation and friction have obvious effects on the radius of elastic-plastic boundary. The expressions of elastic deforming volume and plastic deforming volume in the plastic zone were presented together with the average plastic volumetric strain. A testing method for dilation angle was given. It is proven by examples that ignoring the elastic strain in plastic zone is unreasonable. With the increase of dilation angle，the radius R decreases gradually while the average plastic volumetric strain increases.
Key words: dilatancy；spherical cavity expansion； elasto-plastic analysis
