【目的】在工程环境中，砂土地基通常处于多种应力的作用下，包括各种荷载的应力以及地下水的渗流等因素等复杂的状态，探究黄土掺量对砂土应力–渗流的耦合关系的影响，达到改良砂土的目的。【方法】结合山西省晋中市太谷区道路工程面临的实际问题，以晋中地区砂土为研究对象，针对大方量砂土改良进行研究，结合材料的易取性、工程造价和工程实际，采用黏粒含量较低的黄土来改良砂土，并充分考虑应力场与渗流场的耦合作用，借助应力应变控制式三轴剪切渗透试验仪系统研究改良效果。【结果】结果显示：在剪切过程中，砂土的强度随含水率增大而减小，随围压的增大而减小，其受黄土掺量影响最大；砂土渗透性随应力变化而变化，渗透系数随着轴向应力的增大而减小，且砂土渗透系数随着黄土掺量的增大出现数量级的下降。【结论】根据砂土应力–渗流耦合试验所提供的数据分析，证明了掺入当地黄土对于改善砂土性质的有效性。尽管当地黄土和黏土在黏性上有一定差异，但其在强度、渗透性等方面的特性依旧能够取得类似的改良效果，从而为实际工程中类似工况提供一种相对经济且有效的改良方法。

[Purpose] In engineering environment, sandy soil foundation is usually under the action of multiple stresses, including stress of various loads and groundwater seepage and other complex states. The effect of loess content on the coupling relationship of silt stress-seepage was explored to achieve the purpose of improving sandy soil. [Method] Combined with the actual problems faced by road engineering in Taigu District, Jinzhong City, Shanxi Province, the sandy soil in Jinzhong area was taken as the research object to study the improvement of large-volume sandy soil. Combining the material accessibility, engineering cost and engineering practice, loess with low clay content was used to improve sandy soil, and the coupling effect of stress field and seepage field was fully considered. The improvement effect was studied by means of a stress-strain controlled triaxial shear permeability tester system. [Result] The results showed that during the shear process, the strength of sandy soil decreased with the increase of water content and the increase of confining pressure, and it was most affected by the loess content. The permeability of sandy soil changed with stress, the permeability coefficient decreased with the increase of axial stress, and the permeability coefficient of sandy soil decreased by an order of magnitude with the increase of loess content. [Conclusion] Based on the data analysis provided by the sand stress-seepage coupling test, the effectiveness of adding local loess to improve the properties of sand has been proven. Although there are certain differences in viscosity between local loess and clay, their properties in strength, permeability, etc. can still achieve similar improvement effects, thus providing a relatively economical and effective improvement method for similar working conditions in actual engineering.

山西省自然科学基金面上项目（202103021223132；202103021224151）；山西农业大学省改革高层次人才引进项目（2021XG009）；国家自然科学青年基金（42207102）；