摘要
钻机钻进过程中钻头旋转产生的扭矩以及作用于钻头的轴推进力是破碎岩石的能量来源,当钻进条件确定时,可用破碎单位体积岩石的实际能耗来反映岩石的物理力学性质。基于此原理在青岛胶州湾海底隧道FK4+375.5的上断面进行了超前地质探孔作业,得到凝灰岩地层中的钻进参数及钻进能量随钻头位移的变化曲线,并利用能量理论对钻进过程中监测的钻机参数进行分析,研究发现:在凝灰岩中,数字钻机参数与围岩岩性响应程度较高,围岩完整、坚硬、无裂隙水时,整体钻进参数值较高;围岩裂隙发育、含水或有断层、夹泥层时,钻进速度、推进力、转速、扭矩、打击能等数据会突变,其值变小。分析所得结果与钻孔取芯、TSP超前预报等物探手段得到的结果基本一致。并采用能量法对围岩进行分析,利用钻进比能划分相应的岩体区段,判断出围岩等级。通过对能量曲线的分析发现,在凝灰岩地层中,当钻进能量小于0.95 kJ时会出现断层或较大的节理裂隙区。
When a drill machine is working, energy of broking rock is produced from the action of torque and propulsion. The torque is resulted from the rotation of the bit, on which the propulsion is acting. When drilling conditions are certain, physical mechanical properties of rocks can be reflected from the energy consumed to break the rocks per unit volume. Based on this theory, advance geological drilling experiment has been performed on fault FK4＋375.5 around the subsea tunnel across Qingdao Jiaozhou bay and the drilling parameters of tuff stratum and the variation of drilling energy with the displacement of bit are obtained. Parameters of a drill have been monitored in drilling process and analyzed using energy theory. The results show that, there is a good correlation between the drilling parameters of a digital drill machine and rock lithology. When surrounding rocks are integrated, hard and in the absence of fracture water, the drilling parameters are high. Conversely, when surrounding rocks are fractured, or in the presence of faults, fracture water and intercalated gouge, there are abrupt changes in the drilling rate, propulsion, rotational speed, torque and hit energy. The values of these parameters decrease markedly. The obtained results are consistent with core-drilling and advance geological prediction using tunnel seismic prediction （TSP）. The above method is used in the classification of surrounding rock. According to the relation between energy curves and classification of surrounding rock, faults or fractured zones will appear in tuff stratum when the value of drilling energy is less than 0.95 kJ.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2012年第8期2457-2464,共8页
Rock and Soil Mechanics
基金
国家重点基础研究发展计划(973)项目(No.2007CB209400)
国家自然科学基金项目(No.40902084
No.50908134)
岩土力学与工程国家重点实验室开放基金(No.Z010905)
山东大学自主创新基金(No.2009TS093)
关键词
能量理论
钻进能量
凝灰岩地层
界面识别
围岩分级
energy theory
drilling energy
tuff stratum
identification of geological interface
classification of surrounding rock
