大连理工大学学报
大連理工大學學報
대련리공대학학보
JOURNAL OF DALIAN UNIVERSITY OF TECHNOLOGY
2014年
5期
543-550
,共8页
施林林%宋玉普%沈璐%王立成
施林林%宋玉普%瀋璐%王立成
시림림%송옥보%침로%왕립성
大骨料混凝土%三轴压荷载历史%应变率%破坏形态%强度损伤
大骨料混凝土%三軸壓荷載歷史%應變率%破壞形態%彊度損傷
대골료혼응토%삼축압하재역사%응변솔%파배형태%강도손상
dam concrete%triaxial compression loading history%strain rate%failure mode%strength damage
利用静、动三轴试验机对大骨料混凝土预先施加三轴压荷载历史,之后对经历荷载历史的试件进行同应变率的单轴受压试验,研究了大骨料混凝土的动态受压性能与所经历的加载速率(应变率为10-5~10-2 s-1)和应力比荷载历史的关系.所有试验的三轴压荷载历史中σ3均加载至2.8fc ,且未达到材料的极限强度,但是大部分试件已产生了微裂缝和不可恢复的变形.试验表明:在单轴受压试验中,大骨料混凝土破坏会沿着已有的裂缝继续发展,破坏形态不同于单轴抗压的柱状破坏,而与三轴压荷载下的斜剪破坏极为相似.经历三轴压荷载历史后的大骨料混凝土的抗压强度随着侧压力的增加而降低,随着应变率的提高而提高.强度损失随着应变率的增加而减小,随着侧压力的增加而增加.
利用靜、動三軸試驗機對大骨料混凝土預先施加三軸壓荷載歷史,之後對經歷荷載歷史的試件進行同應變率的單軸受壓試驗,研究瞭大骨料混凝土的動態受壓性能與所經歷的加載速率(應變率為10-5~10-2 s-1)和應力比荷載歷史的關繫.所有試驗的三軸壓荷載歷史中σ3均加載至2.8fc ,且未達到材料的極限彊度,但是大部分試件已產生瞭微裂縫和不可恢複的變形.試驗錶明:在單軸受壓試驗中,大骨料混凝土破壞會沿著已有的裂縫繼續髮展,破壞形態不同于單軸抗壓的柱狀破壞,而與三軸壓荷載下的斜剪破壞極為相似.經歷三軸壓荷載歷史後的大骨料混凝土的抗壓彊度隨著側壓力的增加而降低,隨著應變率的提高而提高.彊度損失隨著應變率的增加而減小,隨著側壓力的增加而增加.
이용정、동삼축시험궤대대골료혼응토예선시가삼축압하재역사,지후대경력하재역사적시건진행동응변솔적단축수압시험,연구료대골료혼응토적동태수압성능여소경력적가재속솔(응변솔위10-5~10-2 s-1)화응력비하재역사적관계.소유시험적삼축압하재역사중σ3균가재지2.8fc ,차미체도재료적겁한강도,단시대부분시건이산생료미렬봉화불가회복적변형.시험표명:재단축수압시험중,대골료혼응토파배회연착이유적렬봉계속발전,파배형태불동우단축항압적주상파배,이여삼축압하재하적사전파배겁위상사.경력삼축압하재역사후적대골료혼응토적항압강도수착측압력적증가이강저,수착응변솔적제고이제고.강도손실수착응변솔적증가이감소,수착측압력적증가이증가.
The experiments of dam concrete under the dynamic uniaxial compression are carried out after the triaxial compression loading history with the same strain rate by static and dynamic triaxial test equipment.The influence of loading history of strain rate (ranging from 1 0-5 to 1 0-2 s-1 )and stress ratio on the dynamic strength of dam concrete is analyzed.Theσ3 in the triaxial compression loading history is up to 2.8fc,and does not achieve the ultimate strength,but there are slight cracks and the unrecoverable deformation on the specimens.The experimental results show that the failure mode of dam concrete continues to develop along the existing cracks under dynamic uniaxial compression,and it is different from the column failure under uniaxial compression,but similar to the skew shear failure under triaxial compression.After triaxial compression loading history,the strength of dam concrete under uniaxial compression decreases with the increase of confined compressive stress,and increases with the increase of strain rate;the strength damage of dam concrete decreases with the increase of strain rate,and increases with the increase of confined compressive stress.