Mechanical Properties of Continental Clay under Low Confining Pressure.

在2年内。对不同围压作用下的饱和和非饱和陆相粘土进行了静、动态剪切试验。根据这些调查的结果，得到以下结果：1. 低围压下饱和粘土的不排水抗剪强度比高围压下强度增量计算的饱和粘土的不排水抗剪强度大50%。2. 尽管围压和超固结比不同，但饱和粘土的强度各向异性基本不变。3. 非饱和大陆粘土的抗剪强度受干密度和含水量的影响。应力应变关系的屈服点在较高的预应力比（P<@D2c@>D2/sigma<@D2c@>D2）下明显出现，屈服应力随P<@D2c@>D2/sigma<@D2c@>D2和含水量w的变化而变化。45层的抗剪强度（tau<@D2f@>D2）随正应力（digma<@D2f@>D2）的增大而增大，tau<@D2f@>D2-sigma<@D2f@>D2关系的程度（phi）随预约束应力比（P< @D2f@>D2 /sigma< @D2f@>D2）的增大而增大。而且，sin随log线性增加（P<@D2c@>D2/sigma<@D2c@>D2）但逐渐接近于1 P<@D2c@>D2/sigma<@D2c@>D2.5。phi<@D2wn@>D2任何含水量(w)和P< @D2wn@>D2 /sigma< @D2wn@>D2 = n如下式所示。φ< @D2wn@ > D2 = < @D7pi (/) 2 @ > D7 - (< @D7pi (/) 2 @ > D7 -φ< @D2w1@ > D2) exp{——< @D70.434W (P < @D2c@ > D2 /σ< @D2c@ > D2)(/)(π/ 2φ< @D2w1@ > D2) cosphi < @D2w1@ > D2@ > D7} 6。在较小的重复次数（N <100）下，非饱和粘土在重复偏离应力（q<@D2d@>D2）作用下的残余应变与静压缩状态下的轴向应变基本相同7。弹性性能随重复次数的增加而增加。

During 2 Years. We had carried static and dynamics shearing test on saturated and unsaturated continental clay subjected to different confining pressure.On the results of these investigation following results are obtained.; 1. Undrained shearing strengths of saturated clay under low confining pressure are 50% larger than those of saturated clay calculated on the strength increment value under high confining pressure. 2. Strength anisotropy of saturated clay are nearly constant in spite of difference of confining pressure and overconsolidation ratio. 3. Shearing strength of unsaturated continental clay are influenced by the dry density and water content. Yielding point of stress-strain relationship are appeared clearly at higher pre-confined stress ratio ( P<@D2c@>D2/sigmaM<@D2c@>D2 and yield stress are changed on value of P<@D2c@>D2/sigma<@D2c@>D2 and water content W. 4. Shearing strengths (tau<@D2f@>D2) on the 45ﾟ plane increase with normal stress (digma<@D2f@>D2) and the degree(phi) of tau<@D2f@>D2-sigma<@D2f@>D2 relation are increasing with magnitude of pre-con- fined stress ratio ( P<@D2c@>D2/sigma<@D2c@>D2 ). And also , sin phi increases linearly with log( P<@D2c@>D2/sigma<@D2c@>D2 ) but gradually approach to 1 at large P<@D2c@>D2/sigma<@D2c@>D2.5. phi<@D2wn@>D2 any water content (w) and P<@D2c@>D2/sigma<@D2c@>D2= n in shown as following equation . phi<@D2wn@>D2 = <@D7pi(/)2@>D7 - (<@D7pi(/)2@>D7 - phi<@D2w1@>D2) exp { - <@D70.434W(P<@D2c@>D2/sigma<@D2c@>D2)(/)(pi/2-phi<@D2w1@>D2)cosphi<@D2w1@>D2@>D7 } 6. Residual strain of unsaturated clay subjecting to repeated deviator stress ( q<@D2d@>D2 ) is nearly same axial strain under static compression state during smaller repetition (N <100) 7. Elastic properties are increasing with increase of repetition.