上海暗绿色粉质粘土是上海桩基础的持力层。对这层土土样的局部化变形和剪切带形成规律的试验研究将有助于它的基本性状的深入。本文介绍改装的平面应变仪 ,并通过对该层粘土在固结不排水平面应变压缩试验结果的分析研究 ,定量提出上海暗绿色粉质粘土剪切带形成的一些规律 Shanghai dark green silty clay is the pile foundation of Shanghai pile. The experimental study on the formation of local deformation and shear band of this earth-soil sample will contribute to the further development of its basic characters. In this paper, the modified plane strain gauge is introduced. Based on the analysis of the strain-compression test results of this layer of clay on the undrained plane of consolidation, some laws of the formation of the dark green silty clay shear band in Shanghai are quantitatively proposed