岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2014年
2期
321-327
,共7页
左建平%黄亚明%熊国军%刘靖%李蒙蒙
左建平%黃亞明%熊國軍%劉靖%李矇矇
좌건평%황아명%웅국군%류정%리몽몽
岩石力学%应力跌落%能量法%可释放应变能%能量跌落
巖石力學%應力跌落%能量法%可釋放應變能%能量跌落
암석역학%응력질락%능량법%가석방응변능%능량질락
rock mechanics%stress-drop%energy method%releasable strain energy%energy-drop
从能量角度出发,分析了脆性岩石的整个变形破坏过程。列举出岩石破坏过程的各种能量类型并对其分类,通过分析机械能和热能在岩石破坏过程中的不同影响,提出了用能量法分析岩石破坏过程必须区分热能与机械能。根据循环加、卸载曲线讨论了在岩石变形破坏的不同阶段输入的机械能?W与可释放应变能增量 e?U 以及耗散能增量 d?U 之间的关系及变化规律。分析了应力脆性跌落系数存在的不足,提出了一个新的表征岩石破坏的参量,即脆性岩石的能量跌落系数。对不同围压下大理岩和花岗岩破坏过程的应力-应变曲线分析计算,得到了能量跌落系数与围压的关系,以及损伤程度和泊松比对其影响。并通过与现有的应力脆性跌落系数进行对比,说明了本模型的合理性,并认为用其描述岩石的脆性程度在更广泛的围压条件下的适用性。
從能量角度齣髮,分析瞭脆性巖石的整箇變形破壞過程。列舉齣巖石破壞過程的各種能量類型併對其分類,通過分析機械能和熱能在巖石破壞過程中的不同影響,提齣瞭用能量法分析巖石破壞過程必鬚區分熱能與機械能。根據循環加、卸載麯線討論瞭在巖石變形破壞的不同階段輸入的機械能?W與可釋放應變能增量 e?U 以及耗散能增量 d?U 之間的關繫及變化規律。分析瞭應力脆性跌落繫數存在的不足,提齣瞭一箇新的錶徵巖石破壞的參量,即脆性巖石的能量跌落繫數。對不同圍壓下大理巖和花崗巖破壞過程的應力-應變麯線分析計算,得到瞭能量跌落繫數與圍壓的關繫,以及損傷程度和泊鬆比對其影響。併通過與現有的應力脆性跌落繫數進行對比,說明瞭本模型的閤理性,併認為用其描述巖石的脆性程度在更廣汎的圍壓條件下的適用性。
종능량각도출발,분석료취성암석적정개변형파배과정。열거출암석파배과정적각충능량류형병대기분류,통과분석궤계능화열능재암석파배과정중적불동영향,제출료용능량법분석암석파배과정필수구분열능여궤계능。근거순배가、사재곡선토론료재암석변형파배적불동계단수입적궤계능?W여가석방응변능증량 e?U 이급모산능증량 d?U 지간적관계급변화규률。분석료응력취성질락계수존재적불족,제출료일개신적표정암석파배적삼량,즉취성암석적능량질락계수。대불동위압하대리암화화강암파배과정적응력-응변곡선분석계산,득도료능량질락계수여위압적관계,이급손상정도화박송비대기영향。병통과여현유적응력취성질락계수진행대비,설명료본모형적합이성,병인위용기묘술암석적취성정도재경엄범적위압조건하적괄용성。
This paper analyzes the whole brittle failure process of rock from energy point, which enumerates and classifies variety of energy forms in the process of rock failure. It presents that thermal energy and mechanical energy must be distinguished when energy method is used to analyze the failure process of rock, because they have different effects. The relationship among input mechanical energy increment?W , releasable strain energy increment e?U and dissipated energy increment d?U is discussed through a symbolic cyclic loading-unloading curve;in addition, their transformation laws in different stages throughout the whole process are presented. The coefficient of brittle stress-drop has some shortcomings;and a new coefficient of energy-drop is presented in detail. Finally, this paper calculates energy-drop coefficient through the stress-strain curves in a series of confining pressure conditions of marble and granite, and obtains the relationship between the energy-drop coefficient and confining pressure. In addition, the effects of damage variable and Poisson's ratio on energy-drop coefficient are discussed. The comparison between brittle stress-drop coefficient and energy-drop coefficient with the existing experimental data shows that our model is reasonable and can be applied to more wide confining pressure conditions.