(浙江大學(xué) 巖土工程研究所， 杭州 310027)
摘 要: 在考慮材料剪脹性和塑性區(qū)彈性變形的情況下，研究了塑性區(qū)中彈、塑性變形情況以及對(duì)應(yīng)力場(chǎng)、位移場(chǎng)的影響。研究表明剪脹角ψ和內(nèi)摩擦角φ對(duì)彈塑性交界處半徑R有顯著影響；給出了塑性區(qū)中平均體積應(yīng)變及彈、塑性變形體積的計(jì)算公式和剪脹角的測(cè)試方法。 通過算例研究發(fā)現(xiàn)，彈塑性交界處半徑R隨著剪脹角ψ的增大而逐漸減 小，塑性區(qū)平均體積應(yīng)變卻隨著剪脹角ψ的增大而增大。研究表明塑性區(qū)中彈性變形部分忽略是不合理的。
關(guān)鍵字: 剪脹性；球形空腔擴(kuò)張；彈塑性分析
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
