荆门膨胀土的Hvorslev真强度参数

Hvorslev Strength Parameters of Jingmen Expansive Soils

相对于Mohr-Coulomb抗剪强度理论,Hvorslev真强度理论能够考虑孔隙比的影响,能够统一描述正常固结与超固结土的抗剪强度,但是Hvorslev真强度参数实测结果较少。基于荆门黄褐色膨胀土与棕褐色膨胀土泥浆固结样、压实样、原状样的直剪试验结果以及泥浆固结样的一维压缩试验结果,标定了2种荆门膨胀土的Hvorslev真强度参数。结果表明:(1)荆门黄褐色膨胀土、棕褐色膨胀土的有效真内摩擦角分别为14.5°、24.0°,有效基础内摩擦角分别为2.3°、1.5°。(2)Hvorslev真强度理论可有效地统一刻画荆门膨胀土原状样、压实样、泥浆固结样的抗剪强度,且具有较高的精度。(3)相对于Hvorslev真强度理论,Mohr-Coulomb强度理论对不同的试样类型、不同的压实度、不同的超固结比,需采用不同的强度参数。

Compared with Mohr-Coulomb failure theory,Hvorslev’s theory can reflect the effect of void ratio,and has the same set of parameters for overconsolidated and normally consolidated soils.However,there are few works on evaluating the Hvorslev strength parameters.Based on the test results of direct shear tests and one-dimensional compression tests of intact,compacted and reconstituted specimens of Jingmen yellowish-brown expansive soil and brown expansive soil,the Hvorslev strength parameters of the two soils were calibrated.The results showed that:(1)The effective true friction angles of Jingmen yellowish-brown expansive soil and brown expansive soil were 14.5°and 24.0°,respectively,and the effective base friction angles were 2.3°and 1.5°,respectively.(3)Hvorslev’s theory could predict the shear strength of intact,compacted and reconstituted specimens of Jingmen expansive soil by the same set of Hvorslev strength parameters with high accuracy.(3)Compared with Hvorslev’s theory,Mohr-Coulomb failure theory needed adopt different strength parameters for different types of specimens,different percent compaction,or different overconsolidation ratio.