基于钻进过程指数定量评价岩体完整性原位试验研究

钻孔过程中钻具实时响应特征蕴藏着大量工程地质信息,通过解译钻进数据定量评价岩体完整性,可为快速获取工程岩体的地质特征提供新途径。采用高精度数字液压、扭矩、转速和激光位移传感器监测地质钻机传动部位,搭建了新型地质钻机数字钻进监测系统。开展了均质材料和裂隙岩体原位钻进试验,根据实时、连续及同步获取的钻具响应特征参数,建立了钻进压力、钻进扭矩、钻头转速和钻进速度的函数关系。在此基础上,滤除钻机机械参数对钻进速度的影响,提出了用于表达岩体完整性的新指标——钻进过程指数。研究发现,钻进过程指数的数字变化趋势能综合反映岩体的破碎程度,能通过信息化方法和数据运算获取岩体完整性,削减了人工统计RQD和编纂岩芯柱状素描图等繁杂的工序,还降低了人为主观因素的不利影响。

In-situ tests on quantitative evaluation of rock mass integrity based on drilling process index

The real-time response characteristics of drilling tools contain important engineering geological information. By interpreting the drilling data, the rock mass integrity can be quantitatively evaluated, which provides a new way to quickly obtain the geological characteristics of engineering rock mass. A new type of digital geological drilling monitoring system is established by using the high-precision digital hydraulic, torque, rotational speed and laser displacement sensors to monitor the transmission part of geological drill. Based on the real-time, continuous and synchronous drilling response characteristic parameters of drilling tools, the functional relationships among drilling thrust, rotational torque, rotational speed and drilling rate are established. On this basis, the influences of drilling machine parameters on drilling rate are filtered out, and a new index, drilling process index, is proposed to express the rock mass integrity. The digital change of the drilling process index can comprehensively reflect the fragmentation degree of rock mass, and the rock mass integrity can be obtained through the information method and data operation. The complicated procedures such as statistical work of RQD and drillingcore sketch are reduced, and the adverse influences of human subjective factors are also reduced.