湖南大学学报(自然科学版)
湖南大學學報(自然科學版)
호남대학학보(자연과학판)
JOURNAL OF HUNAN UNIVERSITY(NATURAL SCIENCES EDITION)
2014年
9期
79-85
,共7页
苏永华%毛克明%梁斌%付雄%贺炜
囌永華%毛剋明%樑斌%付雄%賀煒
소영화%모극명%량빈%부웅%하위
深部隧道%分层断裂%应变软化%峰后脆性%力学机制
深部隧道%分層斷裂%應變軟化%峰後脆性%力學機製
심부수도%분층단렬%응변연화%봉후취성%역학궤제
deep-buried tunnel%layered fracture%strain-softening%peak-brittleness of rock%mechani-cal-mechanism
为了揭示深部隧道工程围岩的分层断裂机理而展开数值实验研究。分析了深部地层岩体历史及赋存环境,认为深部岩体在力学上处于峰后阶段,根据岩石峰后应力应变特征选定了围岩的峰后特征指标及其开挖响应方程。建立了数值实验模型,设计了开挖数值模拟的围岩响应监控方案。完成了大量的开挖数值模拟,实现了深部围岩分层断裂现象在数值模拟中的重现。基于实验中围岩应力、变形分布的全程监测结果,在确定围岩分层断裂产生条件的基础上,进一步研究得到了围岩分层断裂层数、分层断裂圈半径、最大峰值应力等参数与峰后特征指标的关系。根据地下结构开挖围岩应力重分布及岩石力学破裂机理,分析了分层断裂中次生自由面、多重似开挖面形成的力学机制。所得数值模拟结果,为深部工程围岩的分层断裂提供了验证依据,消解了长期以来数值模拟中没有观察到分层断裂现象的困惑。
為瞭揭示深部隧道工程圍巖的分層斷裂機理而展開數值實驗研究。分析瞭深部地層巖體歷史及賦存環境,認為深部巖體在力學上處于峰後階段,根據巖石峰後應力應變特徵選定瞭圍巖的峰後特徵指標及其開挖響應方程。建立瞭數值實驗模型,設計瞭開挖數值模擬的圍巖響應鑑控方案。完成瞭大量的開挖數值模擬,實現瞭深部圍巖分層斷裂現象在數值模擬中的重現。基于實驗中圍巖應力、變形分佈的全程鑑測結果,在確定圍巖分層斷裂產生條件的基礎上,進一步研究得到瞭圍巖分層斷裂層數、分層斷裂圈半徑、最大峰值應力等參數與峰後特徵指標的關繫。根據地下結構開挖圍巖應力重分佈及巖石力學破裂機理,分析瞭分層斷裂中次生自由麵、多重似開挖麵形成的力學機製。所得數值模擬結果,為深部工程圍巖的分層斷裂提供瞭驗證依據,消解瞭長期以來數值模擬中沒有觀察到分層斷裂現象的睏惑。
위료게시심부수도공정위암적분층단렬궤리이전개수치실험연구。분석료심부지층암체역사급부존배경,인위심부암체재역학상처우봉후계단,근거암석봉후응력응변특정선정료위암적봉후특정지표급기개알향응방정。건립료수치실험모형,설계료개알수치모의적위암향응감공방안。완성료대량적개알수치모의,실현료심부위암분층단렬현상재수치모의중적중현。기우실험중위암응력、변형분포적전정감측결과,재학정위암분층단렬산생조건적기출상,진일보연구득도료위암분층단렬층수、분층단렬권반경、최대봉치응력등삼수여봉후특정지표적관계。근거지하결구개알위암응력중분포급암석역학파렬궤리,분석료분층단렬중차생자유면、다중사개알면형성적역학궤제。소득수치모의결과,위심부공정위암적분층단렬제공료험증의거,소해료장기이래수치모의중몰유관찰도분층단렬현상적곤혹。
Numerical simulation research has been conducted in order to reveal the mechanism of the layered fracture within surrounding rock in deep-buried tunnel.Analysis of the history of the rock mass and its environment suggests that the mechanism of the deep rock mass was located in the post-peak stage, the post-peak characteristic indexes and the excavation response equations were selected based on the post-peak stress-strain characters of rock mass.A numerical model was established,a monitoring scheme of surrounding rock response was designed which was caused by excavation,and a fair amount of excavation was completed by numerical simulation method,and the phenomenon of layered fracture within surround-ing rock was reproduced in the numerical simulation.According to the monitoring results about the rock stress and deformation distribution from the experiment,and based on the critical conditions under which the layered fracture in surrounding rock was emerged,the relationship of the fracture layer number of sur-rounding rock,the radius of layered fracture zone and the maximum peak stress with the post-peak charac-teristic indexes were studied.Based on the surrounding rock stress redistribution related to the excavation of underground structure and the fracture mechanism of rock mechanics,this paper analyzed the mechani-cal mechanism of the formation of secondary free-surface and multiple excavation surface.The numerical results provide the basis for the layered fracture in deep surrounding rock,and the confusion about the un-observed phenomena of layered fracture in numerical simulation is also eliminated.