一、前言作者曾于1967年先后两次在《日本矿业会志》发表了题为“煤矿存在的底臌现象及其措施”的报告。阐述了通过模拟试验研究探讨过影响巷道底板底臌量的各种因素(从巷道垂直地表算起所达到的深度、上部煤层和巷道间的距离、底板下面松软层的厚度)。这篇是第三次报告。是谈为防止底臌而施工底锚杆所得的效果的报告。在一、二次报告中曾提到,巷道发生底臌以后,研究如何提高拉底施工时的效率或讨论它的机械化,还不如考虑采取不使它发生底臌的措施。在日本煤矿,除了为防止底臌而采取将底板爆破这一经验(据报导高岛煤矿收到好的效果,但常盘煤矿试验没有成功)外,还没有其他任何好的办法。在 I. Preface The author has twice in 1967 published a report titled “The End of the Coal Mine Phenomenon and Its Measures” at the “Japan Mining Association.” The factors affecting the thickness of roadway bottom are discussed through simulation tests (the depth from the vertical surface of the roadway, the distance between the upper coal seam and the roadway, the thickness of the soft layer under the floor). This is the third report. It is a report on the effect of constructing anchor bolts to prevent bottoming. In the first and second reports, it has been mentioned that after the roadway has been shattered, it may be better to consider measures that will not make it worse if we are to study how to improve the efficiency of bottoming construction or to discuss its mechanization. At Japan’s coal mines, there is no other good alternative to blasting the floor to prevent bottoming, which reportedly received good results from Takashimai mine but failed to succeed in the Changpan mine. in