在煤矿地下水库中，煤柱坝体处于动态扰动的干湿环境中，单一研究煤在干湿循环或循环加卸载条件下的力学特征不够全面、客观。针对该问题，通过试验研究了经过干湿循环处理后的煤样在差速循环荷载作用下的力学特征。将煤样分为4组进行试验，第1组处于自然状态，第2组干湿循环10次，第3组干湿循环40次，第4组一直浸泡在水中；设计了2种试验模式，模式1为快速加载、慢速卸载，模式2为慢速加载、快速卸载。重点分析了煤样应变、割线模量、泊松比随循环次数的演化规律，结果表明：加载模式对煤样的力学性质影响明显，煤样在模式1下的峰值和残余应变比模式2大；整个循环阶段没有发生破坏的煤样在模式1下产生了更大的割线模量增量；泊松比在前几个循环级缓慢增加，到最后2个循环级或破坏前的循环级中快速增大，经过干湿循环的煤样泊松比增量高于自然状态下的煤样。试验结果可为地下水库中的煤柱坝体稳定性设计提供安全方面的指导，以增强煤柱坝体的稳定性和安全性。

In underground coal mine reservoirs, coal pillar dams are subjected to dynamic dry-wet environmental disturbances. Studying the mechanical characteristics of coal solely under dry-wet cycling or cyclic loading and unloading conditions is not comprehensive or objective enough. To address this problem, the mechanical characteristics of coal samples after dry-wet cyclic treatment under differential cyclic loading were studied experimentally. Coal samples were divided into four groups for testing: Group 1 was in a natural state, Group 2 underwent 10 dry-wet cycles, Group 3 underwent 40 dry-wet cycles, and Group 4 was continuously soaked in water. Two test modes were designed: Mode 1 featured rapid loading and slow unloading, while Mode 2 involved slow loading and rapid unloading. The evolution trend of strain, secant modulus, and Poisson′s ratio of coal samples with the number of cycles was analyzed. Results revealed that the loading mode significantly affected the mechanical properties of coal samples. Peak and residual strains of coal samples under Mode 1 were higher than those under Mode 2. Coal samples without damage during the entire cyclic loading phase exhibited greater secant modulus increments under Mode 1. Poisson′s ratio increased gradually during the initial loading cycles but rose sharply in the last two or pre-failure cycles. The Poisson′s ratio increment of coal samples after dry-wet cycling was higher than those in natural state. These findings can provide safety guidance for the stability design of coal pillar dams in underground reservoirs, aiming to enhance their stability and safety.