In order to study and analyze the stability of engineering rock mass under non-uniform triaxial stress and obtain the evolution mechanism of the whole process of fracture,a series of conventional triaxial compression ...In order to study and analyze the stability of engineering rock mass under non-uniform triaxial stress and obtain the evolution mechanism of the whole process of fracture,a series of conventional triaxial compression tests and three-dimensional numerical simulation tests were carried out on hollow granite specimens with different diameters.The bearing capacity of hollow cylindrical specimen is analyzed based on elasticity.The results show that:1)Under low confining pressure,the tensile strain near the hole of the hollow cylindrical specimen is obvious,and the specimen deformation near the hole is significant.At the initial stage of loading,the compressive stress and compressive strain of the specimen are widely distributed.With the progress of loading,the number of microelements subjected to tensile strain gradually increases,and even spreads throughout the specimen;2)Under conventional triaxial compression,the cracking position of hollow cylinder specimens is concentrated in the upper and lower parts,and the final fracture mode is generally compressive shear failure.The final fracture mode of complete specimen is generally tensile fracture.Under high confining pressure,the tensile cracks of the sample are concentrated in the upper and lower parts and are not connected,while the cracks of the upper and lower parts of the intact sample will expand and connect to form a fracture surface;3)In addition,the tensile crack widths of intact and hollow cylindrical specimens under low confining pressure are larger than those under high confining pressure.展开更多
该文报道了2017年在海南省文昌、儋州市和澄迈县采获的吸血蠓2属23种,其中库蠓属22种,蠛蠓属1种;发现1新种,儋州库蠓(Culicoides danzhouensis Liu et Liang,sp.nov.);中国新纪录1种,汸克库蠓(C. pangkorensis Wirth et Hubert,1989);...该文报道了2017年在海南省文昌、儋州市和澄迈县采获的吸血蠓2属23种,其中库蠓属22种,蠛蠓属1种;发现1新种,儋州库蠓(Culicoides danzhouensis Liu et Liang,sp.nov.);中国新纪录1种,汸克库蠓(C. pangkorensis Wirth et Hubert,1989);海南省首次记录1种,柯卡库蠓(C. calcaratus Wirth et Hubert,1989)。文昌市分布17种,儋州市18种,澄迈县19种。儋州库蠓的翅与曲斑库蠓(C. recurvus Delfinado,1961)相近似,但后者触须短,触须比2.2;雄虫阳基侧突有窄的愈合,近中部外侧无角突,第9背板后缘中部有一微突,第9腹板膜无微毛与本新种明显不同。儋州库蠓雄虫的尾器与泸水库蠓(C. lushuiensis Liu et Feng,2018)也相近似,但后者翅面淡斑的数量和形态第9腹板膜无微毛,阳茎拱高约为阳茎中叶总长的1/5与本新种明显不相同。新种模式标本保存在北部战区疾病预防控制中心(沈阳110034)。展开更多
基金Projects(52074116,51804113)supported by the National Natural Science Foundation of China。
文摘In order to study and analyze the stability of engineering rock mass under non-uniform triaxial stress and obtain the evolution mechanism of the whole process of fracture,a series of conventional triaxial compression tests and three-dimensional numerical simulation tests were carried out on hollow granite specimens with different diameters.The bearing capacity of hollow cylindrical specimen is analyzed based on elasticity.The results show that:1)Under low confining pressure,the tensile strain near the hole of the hollow cylindrical specimen is obvious,and the specimen deformation near the hole is significant.At the initial stage of loading,the compressive stress and compressive strain of the specimen are widely distributed.With the progress of loading,the number of microelements subjected to tensile strain gradually increases,and even spreads throughout the specimen;2)Under conventional triaxial compression,the cracking position of hollow cylinder specimens is concentrated in the upper and lower parts,and the final fracture mode is generally compressive shear failure.The final fracture mode of complete specimen is generally tensile fracture.Under high confining pressure,the tensile cracks of the sample are concentrated in the upper and lower parts and are not connected,while the cracks of the upper and lower parts of the intact sample will expand and connect to form a fracture surface;3)In addition,the tensile crack widths of intact and hollow cylindrical specimens under low confining pressure are larger than those under high confining pressure.
文摘该文报道了2017年在海南省文昌、儋州市和澄迈县采获的吸血蠓2属23种,其中库蠓属22种,蠛蠓属1种;发现1新种,儋州库蠓(Culicoides danzhouensis Liu et Liang,sp.nov.);中国新纪录1种,汸克库蠓(C. pangkorensis Wirth et Hubert,1989);海南省首次记录1种,柯卡库蠓(C. calcaratus Wirth et Hubert,1989)。文昌市分布17种,儋州市18种,澄迈县19种。儋州库蠓的翅与曲斑库蠓(C. recurvus Delfinado,1961)相近似,但后者触须短,触须比2.2;雄虫阳基侧突有窄的愈合,近中部外侧无角突,第9背板后缘中部有一微突,第9腹板膜无微毛与本新种明显不同。儋州库蠓雄虫的尾器与泸水库蠓(C. lushuiensis Liu et Feng,2018)也相近似,但后者翅面淡斑的数量和形态第9腹板膜无微毛,阳茎拱高约为阳茎中叶总长的1/5与本新种明显不相同。新种模式标本保存在北部战区疾病预防控制中心(沈阳110034)。
