Digital monitoring of rotary-percussive drilling with down-the-hole hammer for profiling weathered granitic ground  

作　　者：Wendal Victor Yue Siyuan Wu Manchao He Yafei Qiao Zhongqi Quentin Yue 

机构地区：[1]Department of Geotechnical Engineering,College of Civil Engineering,Tongji University,Shanghai,200092,China [2]Department of Civil Engineering,Faculty of Engineering,The University of Hong Kong,Pokfulam Road,Hong Kong,China [3]State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Beijing,100083,China [4]Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai,200092,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第5期1615-1636,共22页岩石力学与岩土工程学报（英文版）

基　　金：supported by grants from the Research Grant Council of the Hong Kong Special Administrative Region,China(Project Nos.HKU 7137/03E and R7005/01E)。

摘　　要：Rock and geotechnical engineering investigations involve drilling holes in ground with or without retrieving soil and rock samples to construct the subsurface ground profile.On the basis of an actual soil nailing drilling for a slope stability project in Hong Kong,this paper further develops the drilling process monitoring(DPM)method for digitally profiling the subsurface geomaterials of weathered granitic rocks using a compressed airflow driven percussive-rotary drilling machine with down-the-hole(DTH)hammer.Seven transducers are installed on the drilling machine and record the chuck displacement,DTH rotational speed,and five pressures from five compressed airflows in real-time series.The mechanism and operations of the drilling machine are elaborated in detail,which is essential for understanding and evaluating the drilling data.A MATLAB program is developed to automatically filter the recorded drilling data in time series and classify them into different drilling processes in sub-time series.These processes include penetration,push-in with or without rod,pull-back with or without rod,rod-tightening and rod-untightening.The drilling data are further reconstructed to plot the curve of drill-bit depth versus the net drilling time along each of the six drillholes.Each curve is found to contain multiple linear segments with a constant penetration rate,which implies a zone of homogenous geomaterial with different weathering grades.The effect from fluctuation of the applied pressures is evaluated quantitatively.Detailed analyses are presented for accurately assess and verify the underground profiling and strength in weathered granitic rock,which provided the basis of using DPM method to confidently assess drilling measurements to interpret the subsurface profile in real time.

关 键 词：Drilling process monitoring(DPM) Down-the-hole(DTH)hammer Percussive-rotary drilling Weathering granitic rocks 

分 类 号：TD804[矿业工程—矿山开采] TN958[电子电信—信号与信息处理]