为研究无侧限和有侧限条件下软岩贯入破坏特征，结合声发射检测技术和电镜扫描试验进行泥岩立方体试样常截面滚刀贯入试验，分析试验过程中荷载-贯入度曲线和声发射参数特征，并对岩石渣块断口进行细观电镜扫描，研究了破坏时细观和宏观裂纹形成过程。试验结果表明，（1）无侧限和有侧限贯入试验中荷载-贯入度曲线在跃进荷载处均出现明显峰值，跃进荷载峰值以后无侧限试样完全破坏，有侧限试样尚未完全破坏；（2）当宏观裂纹产生时无侧限试样声发射参数出现明显峰值，主要源于该宏观裂纹在试样内部的扩展。有侧限试样破坏过程中出现多次声发射参数峰值，对应多条宏观裂纹形成和扩展；（3）常截面滚刀贯入过程中试样内部出现微滑动，剪切破坏现象比较明显，可以认为滚刀贯入过程中泥岩破坏模式以剪切破坏为主。

The cubic mudstone specimens are indented with constant cross-section(CCS) disc cutter to study the fragmentation characteristics of soft rock in indentation tests with or without lateral confinement. The acoustic emission technique and scanning electron microscope analysis are employed to analyze the failure information. The load-penetration curves and acoustic emission parameters are studied with the observation and detection of macrocrack formation processes and mesoscopic failure characteristics. The results show that: (1) The load-penetration curves appear distinct peak value in both cases, after that the unconfined specimen is completely broken down and the confined one still could bear load at a pretty high level. (2) The acoustic emission parameters reach the peak values when the main macroscopic crack forms and propagates in the unconfined test; the acoustic emission parameters arise for several times in accordance with the initiation and propagation of certain number of macrocrack in the confined test. (3) Micro-slips within mudstone specimens can act as evident shear cracks; and the mudstone fragmentation pattern in indentation test with CCS disc cutter is mainly controlled by shear failure.