An improved plane strain test apparatus was first developed with some solutions for friction problem between load plate and specimen,control precision of ε2 and elimination of influence of confinement of both ends on volumetric strain measurement.

With new developed plane strain apparatus, a series of consolidated undrained plane strain compression tests were carried out on undisturbed clay samples of two main clayey layers.

A plane strain apparatus which has been modified is introduced herein.

In order to deeply research the shear band phenomenon, a plane strain apparatus was developed, and a series of consolidated undrained plane strain compression tests of Shanghai intact clay, lay.

Based on the stress state at failure for coherent and frictional materials in plane strain state,it is hypothesized that the intermediate principal stress,s2,makes the Mohr circles of (s1-s2) and (s2-s3) have the same effect degree of cohesion and friction,and then the intermediate principal stress formula at failure for coherent and frictional materials in plane strain state is obtained.

In accordance With the doubts once judgement brought up in article[1],this article-precise surveys and analyses of the H and D Spectrum in Banner s Series by means of 2 - meter plane grating Spectrograph.