微波照射下岩石损伤CT试验研究

CT test of rock damage under the microwave irradiation

为了进一步研究微波照射下岩石内部损伤演化过程,分析微波照射下岩石内部裂纹产生及延伸情况,完善岩石强度劣化机理,采用CT技术对微波照射后不同产地2种花岗岩试件进行扫描,并计算其损伤变量,探讨不同产地2种花岗岩内部矿物成分对微波照射岩石损伤的影响,最后对平山县花岗岩不同含水率试件经微波照射后进行抗剪切试验。结果表明:通过CT探伤设备从细观分析可知,微波照射下岩石损伤是由岩石试件中"危险区域"内吸波矿物引起;不同产地的花岗岩,引发岩石损伤的"危险区域"不同;微波照射下岩石内部裂纹是由局部产生并延续扩展整个岩体试件,岩石强度下降是由吸波点劣化,其特性急剧衰变引起;花岗岩矿物成分中黑云母、角闪石介电常数较大,是主要的吸波矿物;岩石含水率的增加在微波照射下能加大岩石损伤程度,降低岩石抗剪切强度。CT技术对微波照射下研究岩石裂纹损伤及演化提供了一种细观的分析过程。

In order to further study the internal damage evolution process of rock,analyze the production and extension of internal crack in rock under microwave irradiation and perfect the rock strength degradation mechanism,two kinds of different regions granite specimens has been scanned by CT technology after microwave irradiation,the damage variable has been calculated,the influence of the mineral composition of two kinds of different regions granite specimens on rock damage by microwave irradiation has been discussed,and the shear experiment of different moisture content of Pingshanxian granite specimens has been carried out after microwave irradiation. The result of the tests indicates that rock damage is caused by the absorbing mineral of the ＂danger zone＂in rock specimen under microwave irradiation from mesoscopic analysis by CT detection device; the ＂danger zone＂of leading to the rock damage is different from different regions granite; the internal cracks of rock is produced by local and further expand the rock specimen under microwave irradiation,rock strength degradation is caused by degradation of absorbing points,which characteristics decay sharply; biotite and hornblende which has big dielectric constant is the main absorbing mineral in granite mineral composition; the increase of moisture content of rock can increase rock damage degree and reduce the rock shear strength under microwave irradiation.CT technology provides a mesoscopic analysis process of studying crack damage of rock and evolutionary under microwave irradiation.