基于多曲率压头的钻孔横向贯入仪研制及其初步应用

针对深部岩土工程岩石参数获取成本高的问题,借鉴压痕试验技术,研制钻孔横向贯入仪,用于在钻孔中测定岩石的相关力学参数。该设备具有便携、快捷、高效、低成本的特点。该设备通过获取4个不同曲率半径的压头在压入过程中的载荷–位移曲线,并对这些曲线进行分析从而获取岩石的相关力学参数。在大理石上进行钻孔横向贯入仪的初步应用,并在试验中引入声发射监测塑性变形的发展情况,揭示试验的压入曲线特性,从试验曲线中提取岩石的模量,通过与单轴试验结果进行对比,用钻孔横向贯入仪试验曲线提取的模量介于单轴试验的割线模量和弹性模量之间,并且与割线模量较为接近。认为钻孔横向贯入仪的试验结果可以代表现场岩石的力学参数,可供工程参考。

DEVELOPMENT AND PRELIMINARY APPLICATION OF DRILLHOLE PENETROMETER INSTRUMENT BASED ON MULTI-CURVATURE INDENTER

Drillhole penetrometer instrument is developed to solve the high cost problems existing in acquiring the rock parameters in deep geotechnical engineering；it uses the technology of indentation test for references and is applied to measure the rock?s mechanical parameters in drillhole. This apparatus was characterized by portable，convenience，efficiency，and low-cost. The apparatus would acquire the load-displacement curves produced by four indenters with different curvature radiuses in the process of loading. The elastic-plastic parameters could be acquired by the analysis of these curves. The preliminary application of drillhole penetrometer instrument was conducted on the marble，and during which the plastic deformation development situation was monitored by introducing acoustic emission technology，and thus show us the characteristics of the identification curves. The elastic modulus value was acquired through the relevant research curves and then according to the contrast between the results of this research and uniaxial compression test，the modulus value extracted through the curves of drillhole penetrometer instrument is between the value of secant modulus and modulus of elasticity in uniaxial compression test and is closer to secant modulus. As a result，it scientifically proves that the research results acquired through drillhole penetrometer instrument can represent the mechanical parameters in field rock.