岩芯回弹测试方法

Schmidt hammer test methods for rock core

为利用回弹仪快速确定岩芯强度,根据回弹仪的原理和岩芯的特征,对岩芯回弹测试方法进行研究。在选择回弹仪型号时,轻型为宜,0.735 J的最佳;为保证回弹仪垂直冲击岩芯表面,且在冲击过程中岩芯不发生回弹,应使用辅助装置,包括钢基座和导向管;测点均匀布置在某一横断面的圆周上,间隔90°,每个测点锤击1次,记录回弹值。由于岩芯回弹测试垂直向下锤击,应对回弹值进行修正,然后再取4个测点回弹修正值的平均值作为岩芯在这一断面处的回弹值。通过回弹试验发现,利用这种方法获取岩芯的回弹值,效果较好。

In order to quickly determine the rock core strength by using Schmidt hammer, a new Schmidt hammer test method for rock core was studied according to the principle of Schmidt hammer and core’s characteristics. When selecting Schmidt hammer model, L -type was appropriate, and the best is 0.735 J. In order to ensure that the Schmidt hammer vertically impact the core surface without rebound in the impact process, the auxiliary device should be used, including the steel base and the guide pipe. Measuring points were uniformly distributed on circumference of a certain cross section with interval of 90° and each measuring point was hammered for one time and the rebound values were recorded. Vertically downward hammering was carried out during rock core rebound test, thus rebound value should be corrected, and then the average value of corrected rebound values of four measuring points should be taken as the rebound value of cross section of the rock core. The Schmidt hammer test shows that the rebound values of rock core obtained in this method are trusted.