点荷载法测试易风化泥质岩强度的可靠性分析

发布时间：2018-07-09 09:43

本文选题：点荷载试验 + 岩石强度　；参考：《岩土力学》2014年S1期

【摘要】：在川南地区在近年的煤炭开发过程中,多数基建矿井在巷道开拓期间大量出现围岩软弱、易风化、节理裂隙发育、变形大、支护难、多次返修等严重困扰矿井正常投产的支护难题,为合理选取支护技术,必须对软岩类型及等级进行划分。首先进行地质工程调查,选择巷道主要分布的厚层黑灰色泥岩为研究对象,在井下采用点荷载测试仪对新鲜不规则岩块进行强度测试。在对可疑数据采用Grubbs准则进行取舍后,采用传统法、ISRM法、工程分级法分别进行点荷载强度计算,所得结果采用F检验法和t检验法对各公式计算结果进行随机误差和系统误差检验,研究各方法的适宜性。研究发现,在对泥岩进行点荷载测试时,传统法和ISRM法较工程分级法所得单轴抗压强度平均值的随机误差和系统误差小,更适宜作为该类岩性进行工程软岩分级评价时的重要指标;点荷载所获泥岩强度值的偏差系数在11%~30%范围内,与一般岩石单轴抗压强度测定值偏差系数接近,具有可靠、快速、方便、费用低的优点,适宜作为围岩取样困难的巷道进行软岩类型评价的测试方法。
[Abstract]:In the process of coal exploitation in recent years in south Sichuan area, the surrounding rock is weak, weathering easily, joints and fissures are developed, deformation is large and support is difficult in most capital construction mines during roadway development. In order to select the support technology reasonably, the types and grades of soft rock must be divided. Firstly, geological engineering investigation was carried out, and the thick layer black gray mudstone, which was mainly distributed in roadway, was selected as the research object, and the strength of the fresh irregular rock mass was tested by point load tester in the downhole. After adopting Grubbs criterion to select and choose the suspicious data, the traditional ISRM method and the engineering classification method are used to calculate the point load strength, respectively. The results are tested by F-test method and t-test method to test the random error and systematic error of each formula, and the suitability of each method is studied. It is found that the random error and systematic error of the average value of uniaxial compressive strength obtained by the traditional method and ISRM method are smaller than that of the engineering classification method in the point load test of mudstone. The deviation coefficient of mudstone strength obtained by point load is in the range of 11% and 30%, which is close to the deviation coefficient of general rock uniaxial compressive strength measurement, and is reliable and fast. The advantages of convenience and low cost are suitable for evaluating soft rock types in roadways with difficult sampling of surrounding rock.
【作者单位】：中国矿业大学(北京)力学与建筑工程学院;中国矿业大学(北京)资源与安全工程学院;四川省煤炭产业集团有限责任公司;
【基金】：中央高校基本科研基金资助(No.2012800015DQ) 教育部高校博士点基金资助(No.20130023120011)
【分类号】：TU45

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