风化砂岩地层长螺旋钻机钻孔可行性研究

Study on the drilling feasibility of long spiral drill in weathered sandstone formation

为解决风化砂岩地层进行长螺旋钻进可行性及对钻具磨蚀程度问题,通过抗压强度和全岩分析及磨蚀性试验进行综合分析。研究结果表明:该区强风化砂岩为极软岩,岩体整体破碎,单轴抗压强度平均值为2. 23 MPa,强风化砂岩成分以石英为主,对长螺旋桩机钻具磨蚀程度轻微～中等、中等～很强、很强—极强,随着深度的增加,对钻具的磨损程度逐渐加强,深度在10 m～15 m范围内钻具磨损平均质量约为0 m～5 m深范围内的1. 4倍。在项目区域内施工时,浅、中、深部石英含量的不同导致对钻具产生磨蚀强弱不同,在实际施工时应根据不同岩性调整钻具,提高钻进速度和降低施工成本。

In order to solve the feasibility of long spiral drilling in strongly weathered sandstone formation and the wear degree of drilling tools,the comprehensive analysis of compressive strength and whole rock analysis and abrasive test was carried out.The results show that the strongly weathered sandstone in this area is very soft rock,the whole rock body is broken,the average uniaxial compressive strength is 2.23 Mpa,and the strong weathered sandstone is mainly composed of quartz.The abrasion degree of drill tool of long spiral pile machine is slight to medium,medium to very strong,and very strong to extremely strong.With the increase of depth,the wear degree of drilling tools is gradually strengthened,and the average wear mass of drilling tools in the depth range of 10~15meters is about1.4times that of the depth of 0~5meters.In the construction of the project area,the different content of quartz in shallow,middle and deep leads to different wear and tear of drilling tool.In actual construction,the drilling tool should be adjusted according to different lithology,the drilling speed should be improved and the construction cost should be reduced.