钻进参数用于香港复杂风化花岗岩地层的界面识别  

INTERFACE IDENTIFICATION OF INTRICATE WEATHERED GRANITE GROUND INVESTIGATION IN HONG KONG USING DRILLING PARAMETERS

作　　者：谭卓英[1] 蔡美峰[1] 岳中琦[2] 谭国焕[2] 李焯芬[2] 

机构地区：[1]北京科技大学金属矿山高效开采与安全教育部重点实验室,北京100083 [2]香港大学土木工程系

出　　处：《岩石力学与工程学报》2006年第z1期2939-2945,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：香港特别行政区政府研究基金项目(HKU7005/01E);香港赛马会慈善基金项目

摘　　要：在采用仪器钻进系统对复杂风化花岗岩地层界面进行成功识别的基础上,在复杂风化花岗岩场址的勘探中进行进一步应用和检验。在该风化花岗岩地层中,强风化与中等风化花岗岩交错,地层特征相当复杂。试验采用R–20液压回转式钻机,并安装数字式钻孔过程监测系统,在钻孔过程中对穿孔参数进行自动采集。对穿孔参数的定性和定量分析表明,在此地层中,有效轴压力、钻具转速、冲洗压力、钻头位移及穿孔速率等监测参数在界面处亦具有明显的涨落,说明这些参数与界面处岩石强度的变化具有很好的响应特征,能可靠地揭示复杂地层的变化。同时,采用变斜率法对地层中的主、次界面进行识别。t检验表明,仪器钻进系统对岩土界面识别的置信度为99%。The successful identification of interfaces of simple weathered granite ground in Hong Kong has encouraged its further use of instrumented drilling system as a ground investigation tool in intricate weathered granite strata.In this tested ground,the boreholes reveal that the weathered granite alternately changes between moderately and strongly.AR–20 rotary-hydraulic drill rig is instrumented at the appropriate locations with a digital drilling process monitoring(DPM) system and data acquisition can be automatically carried out during the drilling process.The qualitative and quantitative analyses of penetrating parameters indicate that effective thrust force,rotary speed,flushing pressure,penetrating rate and displacement of the bit fluctuate at ground interfaces.It shows that the parameters get well response with the change of rock strength at the interfaces,which can reveal the change of the intricate granite formation.Besides,a variable-slope method has been established for identification of dominative and subsidiary interfaces in the granite site.The result from t test shows that the confidence of the instrumented drilling system in identification of the geotechnical interfaces is 99%.

关 键 词：岩土力学 仪器钻进系统 穿孔参数 复杂风化花岗岩 界面识别 

分 类 号：TU45[建筑科学—岩土工程]