With the continuous increase of mining amount and the acceleration of green mine construction in China，cemented paste backfill technology has shown a broad application prospect. However，there have been few studies on the mechanical behavior of paste filling materials at different moisture conditions. In order to study the effects of different water content on the uniaxial compression mechanical behaviour of paste backfill materials with low cement content，cemented paste backfill specimens with 3% and 5% cement contents were prepared with tailings，cement and water. The RPH-80 controllable constant temperature-humidity chamber was used to change the specimens moisture content to 0，13%，25% and 36%，respectively. Then the TAW-200 multi-functional mechanical testing machine was used to conduct the uniaxial compression test at a constant displacement rate. The results showed that with the increase of the moisture content，the strength of the backfill decreased. The rate of the decrement in strength gradually accelerated and the relationship between the two parameters could be described quantitatively using a quadratic polynomial fit. The decreasing trend and velocity of the uniaxial compressive strength of the two samples with different cement content were similar. And the compressive strength of cemented paste backfill with 5% cement content was always higher than that of backfill with 3% cement content under different moisture content. On the other hand，with the increase of the moisture content，the elastic modulus of the specimen decreased，the peak strain point first increased and then decreased. The nonlinearity index for the cemented paste backfill was proposed to evaluate the stress-strain curve of cemented paste backfill under different water content. The cemented paste backfill with two different cement content both showed a high nonlinearity at the moisture content of 25%. The nonlinear characteristics of cemented paste backfill could be helpful for the early warning and early intervention of backfill failure. This study provided a reference for further understanding the uniaxial compression mechanical behavior of cemented paste backfill and the safety of backfilling areas.

随着我国矿产资源需求的持续攀升和绿色矿山建设的提速，膏体充填技术展现出广阔的应用前景。然而，关于膏体充填材料在不同含水状态下力学行为的研究较少。为研究不同含水率对低水泥含量膏体充填材料单轴压缩力学行为的影响，以全尾砂、水泥和水为材料制备了3%和5%两种水泥含量的充填体试件（水泥含量3%、5%为水泥质量占尾砂质量的百分比），使用RPH-80型可控式恒温恒湿试验箱将试件分组改造成含水率分别为0、13%、25%和36%的充填体试件后，使用TAW-200多功能力学试验机进行恒定位移加载的单轴压缩试验。试验结果表明：随着含水率的升高，充填体的强度下降，且下降速度逐渐加快，使用二次多项式可以较好地拟合单轴抗压强度和含水率之间的关系，2种水泥含量试件的单轴抗压强度的下降趋势与速度较为相似，且5%水泥含量膏体充填体的抗压强度在不同含水率下始终高于3%水泥含量充填体。另一方面，随着含水率的升高，充填体弹性模量降低，峰值应变点先升高后降低。通过充填体非线性指数衡量不同含水率下膏体充填材料应力-应变曲线的非线性程度，发现2种水泥含量下的充填体均在含水率为25%时表现出较高的非线性，利用好充填材料非线性的特点有助于充填体的失效预警和提前干预，研究结果为深入认识膏体充填材料的单轴压缩力学行为和充填区安全问题提供了参考。