岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2013年
11期
2307-2315
,共9页
岩石力学%冻融%单轴压缩%耦合作用%裂隙岩体%损伤演化模型
巖石力學%凍融%單軸壓縮%耦閤作用%裂隙巖體%損傷縯化模型
암석역학%동융%단축압축%우합작용%렬극암체%손상연화모형
rock mechanics%freeze-thaw%uniaxial compression%coupling effect%jointed rock masses%damage evolution model
针对寒区节理岩体工程结构中的冻融受荷岩体,采用在类岩石材料中预制裂隙的方法模拟节理岩体,通过冻融循环试验和单轴压缩试验,分析裂隙岩样的几何特征(裂隙长度、裂隙倾角)对岩体强度的影响;基于细观损伤理论和宏观统计损伤模型,建立冻融受荷裂隙岩石损伤劣化模型,探讨裂隙岩体在冻融和荷载耦合作用下的损伤劣化机制。研究结果表明:(1)岩石反复冻融引起的损伤是一个疲劳破坏的过程,受荷损伤是岩石类非均质材料各组成成分对力的传递速率以及自身变形差异性引起应力场不均匀分布的过程;(2)冻融和受荷以不同的力学机制促使岩石中裂纹的萌生和扩展,由此诱发的损伤相互耦合,其耦合作用会使总损伤有所劣化;(3)裂隙长度以及冻融循环次数对总损伤的影响较大,而裂隙倾角对总损伤的影响相对较小;(4)相同的冻融循环次数下,裂隙岩样较完整岩样的损伤劣化程度严重。
針對寒區節理巖體工程結構中的凍融受荷巖體,採用在類巖石材料中預製裂隙的方法模擬節理巖體,通過凍融循環試驗和單軸壓縮試驗,分析裂隙巖樣的幾何特徵(裂隙長度、裂隙傾角)對巖體彊度的影響;基于細觀損傷理論和宏觀統計損傷模型,建立凍融受荷裂隙巖石損傷劣化模型,探討裂隙巖體在凍融和荷載耦閤作用下的損傷劣化機製。研究結果錶明:(1)巖石反複凍融引起的損傷是一箇疲勞破壞的過程,受荷損傷是巖石類非均質材料各組成成分對力的傳遞速率以及自身變形差異性引起應力場不均勻分佈的過程;(2)凍融和受荷以不同的力學機製促使巖石中裂紋的萌生和擴展,由此誘髮的損傷相互耦閤,其耦閤作用會使總損傷有所劣化;(3)裂隙長度以及凍融循環次數對總損傷的影響較大,而裂隙傾角對總損傷的影響相對較小;(4)相同的凍融循環次數下,裂隙巖樣較完整巖樣的損傷劣化程度嚴重。
침대한구절리암체공정결구중적동융수하암체,채용재류암석재료중예제렬극적방법모의절리암체,통과동융순배시험화단축압축시험,분석렬극암양적궤하특정(렬극장도、렬극경각)대암체강도적영향;기우세관손상이론화굉관통계손상모형,건립동융수하렬극암석손상열화모형,탐토렬극암체재동융화하재우합작용하적손상열화궤제。연구결과표명:(1)암석반복동융인기적손상시일개피로파배적과정,수하손상시암석류비균질재료각조성성분대력적전체속솔이급자신변형차이성인기응력장불균균분포적과정;(2)동융화수하이불동적역학궤제촉사암석중렬문적맹생화확전,유차유발적손상상호우합,기우합작용회사총손상유소열화;(3)렬극장도이급동융순배차수대총손상적영향교대,이렬극경각대총손상적영향상대교소;(4)상동적동융순배차수하,렬극암양교완정암양적손상열화정도엄중。
For rock masses under freeze-thaw and loading in engineering structures in cold regions,using rock-like materials produced rock specimens with different geometric characteristics,based on the freeze-thaw experiments and uniaxial compression test,the influence of crack dip angle and crack length on the rock masses strength were studied;and combining mesoscopic damage theory and macroscopic statistical damage model,the damage model of freeze-thaw and loading rock masses were established;at the same time,damage degradation mechanism of jointed rock masses under the coupling action of freeze-thaw and loading were discussed. The research results show that:(1) The freeze-thaw damage is a process of fatigue damage;and loading damage is an uneven distribution process of stress field and deformation. (2) Freeze-thaw and loading with different mechanisms promote rock crack initiation and propagation;hence induced damages couple with each other,the coupling of the two will make the total damage deterioration. (3) Crack length and freeze-thaw cycles on total damage is larger;the influence of crack dip angle on the total damage is relatively small. (4) under the same cycles of freeze-thaw,damage degradation of cracking rocks is more serious than the intact samples.