为了更真实地模拟煤岩在掘进巷道迎头等环境下的应力状态，研究三向应力环境下煤岩的损伤变形及瓦斯渗流情况，自主研发了真三轴气-固耦合煤体渗流试验系统。该装置主要由真三轴压力室、液压伺服系统、气体渗流系统和监测与控制系统组成，采用的试件尺寸为200 mm×100 mm×100 mm，可施加的最大轴压(?1)为70 MPa、最大侧压（?2）为35 MPa、最大侧压（?3）为10 MPa、最大瓦斯压力为6 MPa。该装置具有以下特点：(1) ?1、?2采用刚性压头加载，?3采用柔性加载，三向应力分别独立加载；(2) 设计了刚柔性压头及传压滑杆，使得?1与?2方向压头在同时加载过程中互不干扰；(3) 通过伺服液压系统控制加载功能，使得装置性能稳定，应力与位移加载精确，易于控制；(4) 气体渗流系统采用蜂窝孔对试件进行面通气，确保试件进气端瓦斯压力均匀分布；(5) 采用多种高精度传感器进行监测，实时记录煤体所受应力值、变形量及瓦斯渗流量。用两种不同应力路径下的渗流试验对该系统准确性和可靠性进行了验证，结果表明，该装置性能稳定可靠。该装置可用于揭示煤与瓦斯在三向应力条件下的耦合作用机制，为防治瓦斯灾害及研究瓦斯抽采提供了可靠的试验基础。

To realistically simulate stress states of coal in tunneling laneway frontal and other stress environments, a true triaxial gas-solid coupling testing system is developed to examine the damage deformation and gas seepage of coal under three-dimensional (3D) stress condition. The device is composed of a true triaxial pressure chamber, servo-hydraulic system, gas seepage system, and monitoring and control system. The suitable size of a specimen for the equipment is 200 mm×100 mm×100 mm. The maximum pressures of the axial compression (?1), the principal lateral direction (?2), and the secondary lateral direction (?3), and gas are 70, 35, 10 and 6 MPa, respectively. The characteristics of the device are shown as follows: the axial pressure (?1) and the principal lateral pressure (?2) are loaded by rigid head loading methods, and the secondary lateral pressure (?3) is applied by flexible loading. The 3D stresses are applied independently. To ensure the heads at σ1 and the ?2 directions without disturbing by each other at the same loading time, the rigid-flexible head and pressure transmission slider are designed. The loading control functions of the servo-hydraulic system are more likely to be stable and reliable, and the stress and displacement loading can be controlled accurately. Honeycomb holes are used for ventilation of specimen surface in the gas seepage system to ensure the uniform distribution of gas pressure at the inlet of the specimen. A variety of high-precision sensors are used to monitor and record the stress, the deformation and the gas seepage discharge of coal in real-time. Seepage experiments in two different loading paths are performed to verify the accuracy and reliability of the experiment system which performs well. The device can be used to reveal the coupling mechanism of coal and gas under 3D stress conditions, and to provide a reliable experimental basis for prevention and control of gas disaster and investigations on gas extraction.