Based on the MTS815 flex test GT and split Hopkinson pressure bar SHPB,static and dynamic properties of granite in Xinjiang's Tianhu area were studied deeply,Tianhu area is a preselected site for HLW (high level radioactive waste) geological disposal.For granite drill cores in a borehole,static tension tests,static uniaxial compression tests,dynamic tension tests,dynamic compression tests and one dimensional static-dynamic combined loading tests were conducted,respectively.Specifically,all the tested drill cores were taken from the same depth of 360 m,therefore,the test results were considered to be more representative for the granite.The test results showed that the granite's static tension strength is about l1.75 MPa,its static uniaxial compression strength is 175 MPa,the latter is about 14 times of the former;its dynamic tension strength is about 25-35 MPa when the dynamic loading rate is 0.34 × 106-0.51 × 106 MPa/s;its dynamic compression strength is about 138-208 MPa when the strain rate is 80-160 s-1;with increase in the dynamic loading rate or strain rate,either its dynamic tension strength or its dynamic compression strength also increases to show the granite's rate-correlation loading effect feature.Furthermore,the one dimensional static-dynamic combined tension loading tests were conducted,it was shown that with increase in uniaxial static compression,the granite's anti-impact strength increases firstly and then decreases;the granite's anti-impact tension strength reaches the maximum when its static tension stress reaches about 50％ of the granite's static tension strength;meanwhile,with the increase in uniaxial static compression,the granite's static-dynamic combined tension strength increases obviously,especially,its maximum value reaches about three times of the static tension strength and about 1.5 times of the anti-impact dynamic tension strength;the granite's failure mode under the static-dynamic combined loading is also a tension failure one,this is the same as the granite's failure modes under the static tension loading and conventional dynamic loading.Through a series of tests mentioned above,it was shown that the granite's mechanical properties in this area can be considered to be stable and this area can be taken as a pre-selected area for HLW geological disposal;however,the test data are not enough,the other ones,such as,the seepage test and the stress one on site should be done;drill cores should be taken not only from one borehole,but also from different boreholes with different depths;then,rock in this area can be studied fully.The test data and the obtained knowledge here provided a reference for blasting and excavation of deep underground projects and HLW deep geological disposal.%基于MTS815及SHPB装置,分别进行了高放废物地质处置新疆预选区天湖地段花岗岩的静态及动态力学特性试验.针对该区域的钻孔花岗岩岩芯,开展了一系列的静态拉伸、静态单轴压缩、动态拉伸、动态压缩,以及一维动静组合拉伸加载试验.特别是,该批次试验所用岩芯均取自同一深度处(深度360 m左右)的花岗岩,所获得的对比与分析结果对于同一岩石力学特性研究更有代表性意义.测试结果显示:该花岗岩的静态拉伸强度约为11.75 MPa,单轴压缩强度约为175MPa.单轴压缩强度约为抗拉强度的14倍.在加载率为0.34×106～0.51×106 MPa/s时,其动态拉伸强度约为25 ～ 35 MPa.在应变率为80 ～160 s-1时,其动态压缩强度测试值区间为138～208 MPa.并且随着加载率或应变率的提高,无论是动态拉伸强度特性或动态压缩强度特性均随之增大,这说明了花岗岩的率相关加载效应特性.进一步的实施了该花岗岩的一维动静组合拉伸加载试验,发现随着轴向静压的增大,岩石的抗冲击强度呈现出先增大后减小的趋势.大约在静载抗拉强度的50％时,抗冲击拉伸强度达到最大值,随后平缓减小.并且,随着轴向静压的增大,岩石的动静组合拉伸强度亦随之快速增大,最大可达到静载拉伸强度的3倍,抗冲击拉伸动载的1.5倍.同时,在冲击破坏情况下,岩石组合加载破坏模式呈现拉伸破坏,与静态拉伸破坏及一般冲击下的劈裂破坏特征基本一致.综上表明,该地段试验深度处的钻孔岩芯,其力学特性较为稳定,从工程建造角度而言,可作为高放废物地质处置的一个参考预选地段.但试验获取数据尚未充足,需通过不同钻孔以及不同深度处岩石的动、静力学特性试验及渗透试验、地应力测试等其它试验项目,进一步深入研究其在不同轴向静压及不同冲击动载下,岩石承受的临界动载荷值等力学特性.该研究的试验数据与理论可支撑于深部地下工程的爆破开挖及高放废物的深地质处置.
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