赤泥改性黄土的基本工程性质研究

为探究赤泥改性黄土的基本工程特性，进行无侧限抗压试验、直剪试验及渗透试验，得出赤泥改性黄土的最佳配比，建立了抗剪强度、无侧限抗压强度与电阻率的经验公式。通过动三轴试验，分析了循环动荷载下改性黄土的累积塑性变形、动弹性模量及浸出毒性。结果表明，随赤泥含量增加，改性黄土无侧限抗压强度和黏聚力都先增大后减小，当赤泥含量为15%时其28 d无侧限抗压强度达到3.5 MPa，较不掺入赤泥时提高约34.7%；改性黄土的渗透系数随赤泥含量增加先快速降低，至赤泥含量5%后趋于稳定；改性黄土的抗剪强度、无侧限抗压强度与电阻率呈良好的线性关系；改性黄土在循环动荷载下的临界动应力达600 kPa，最大动弹性模量比未改性黄土高出6倍，且其浸出液不具有浸出毒性。

Study of basic engineering properties of loess modified by red mud

In order to explore the basic engineering characteristics of loess modified by red mud, of which the optimum ratio is obtained based on unconfined compression test, direct shear test and seepage test; and then an empirical formula for shear strength, unconfined compression strength and resistivity is established. The cumulative plastic deformation, dynamic elasticity modulus and leaching toxicity of the modified loess under cyclic dynamic loading are analyzed by dynamic triaxial test. The results show that with the increase of red mud content, the unconfined compressive strength and cohesion of the modified loess first increased and then decreased; and when the amount of red mud is near 15%, the unconfined compression strength of 28 d reached 3.5 MPa, which is improved by about 34.7% than no red mud. The permeability coefficient decreased rapidly with the increase of red mud content, and reached the stability when the amount of red mud is 5%. There is a good linear relationship between the shear strength, unconfined compressive strength and resistivity. The critical dynamic stress of the modified loess reaches 600 kPa under cyclic dynamic loading, of which the maximum dynamic electricity modulus is 6 times ones of loess. The leaching solution of the modified soil does not have the toxicity of leaching.