Q_2黄土的非饱和直剪试验研究

The Unsaturated Direct Shear Tests of Q_2 Loess

改进了后勤工程学院研制的国内第一台非饱和土直剪仪,升级为四联非饱和土直剪仪。四联非饱和土直剪仪极大的缩短了试验时间,提高了效率。利用该仪器研究了原状、重塑非饱和Q2黄土的抗剪强度特性。试验结果表明,在试验研究的吸力范围内,原状、重塑Q2黄土的凝聚力均随吸力线性增加,内摩擦角随吸力的变化较小,可以认为是一常数;吸力摩擦角较大,说明Q2黄土的抗剪强度受吸力变化影响较大,也即受含水率变化影响较大。原状Q2黄土的抗剪强度大于重塑Q2黄土,随着吸力增大,结构性增强。

The direct shear apparatus for unsaturated soils developed in Logistical Engineering University,China was improved to quadruplet direct shear apparatus for unsaturated soils.The quadruplet direct shear apparatus of unsaturated soils shortened the test time.The direct shear tests with controlled suction were conducted to study the shear strength of unsaturated intact and remolded Q2 loess using improved quadruplet direct shear apparatus of unsaturated soils.The test results show that the cohesions of unsaturated intact and remolded Q2 loess have a linear increase with the increasing of suction;but the friction angles have little change with the change of suction and the friction angles of suction are big.The shear strength are affected by suction or water content.The shear strength of unsaturated intact Q2 loess are bigger than unsaturated remolded Q2 loess.The strength of structure increases with the increase in suction of intact Q2 loess.