土木建筑与环境工程
土木建築與環境工程
토목건축여배경공정
Journal of Chongqing Jianzhu University
2015年
4期
90-96
,共7页
剪切带%分叉理论%各向异性%平面应变%细观特性
剪切帶%分扠理論%各嚮異性%平麵應變%細觀特性
전절대%분차이론%각향이성%평면응변%세관특성
shear band%bifurcation theory%anisotropy%plane strain%meso feature
针对平面应变条件下各向异性砂土剪切带角度的试验规律,采用传统的3种理论和分叉理论进行对比分析。将平面应变条件下剪切带角度的试验结果按照传统3种理论整理发现,尽管传统3种理论可以估算同种砂剪切带角度的极小、中间和极大值,但无法解释其各向异性规律。砂土在平面应变条件下破坏时会产生明显的剪切带,当剪切带方向和砂土沉积面方向接近时,会较早诱发剪切带的产生,使材料强度降低,造成了平面应变条件下各向异性强度规律明显不同于常规三轴条件下的试验规律,采用分叉理论结合各向异性模型则可以有效解释这个规律。随砂土沉积面角度的变化,模型可以从细观角度解释常规三轴条件下剪切带角度的单调变化的试验规律,结合分叉理论可以描述平面应变条件下其先减小然后增大的规律。通过几种理论对比分析表明,模型结合分叉理论不但能够描述多种应力状态下的平面应变和常规三轴应力条件下剪切带角度表现的不同规律,而且能够从细观角度解释其各向异性成因。
針對平麵應變條件下各嚮異性砂土剪切帶角度的試驗規律,採用傳統的3種理論和分扠理論進行對比分析。將平麵應變條件下剪切帶角度的試驗結果按照傳統3種理論整理髮現,儘管傳統3種理論可以估算同種砂剪切帶角度的極小、中間和極大值,但無法解釋其各嚮異性規律。砂土在平麵應變條件下破壞時會產生明顯的剪切帶,噹剪切帶方嚮和砂土沉積麵方嚮接近時,會較早誘髮剪切帶的產生,使材料彊度降低,造成瞭平麵應變條件下各嚮異性彊度規律明顯不同于常規三軸條件下的試驗規律,採用分扠理論結閤各嚮異性模型則可以有效解釋這箇規律。隨砂土沉積麵角度的變化,模型可以從細觀角度解釋常規三軸條件下剪切帶角度的單調變化的試驗規律,結閤分扠理論可以描述平麵應變條件下其先減小然後增大的規律。通過幾種理論對比分析錶明,模型結閤分扠理論不但能夠描述多種應力狀態下的平麵應變和常規三軸應力條件下剪切帶角度錶現的不同規律,而且能夠從細觀角度解釋其各嚮異性成因。
침대평면응변조건하각향이성사토전절대각도적시험규률,채용전통적3충이론화분차이론진행대비분석。장평면응변조건하전절대각도적시험결과안조전통3충이론정리발현,진관전통3충이론가이고산동충사전절대각도적겁소、중간화겁대치,단무법해석기각향이성규률。사토재평면응변조건하파배시회산생명현적전절대,당전절대방향화사토침적면방향접근시,회교조유발전절대적산생,사재료강도강저,조성료평면응변조건하각향이성강도규률명현불동우상규삼축조건하적시험규률,채용분차이론결합각향이성모형칙가이유효해석저개규률。수사토침적면각도적변화,모형가이종세관각도해석상규삼축조건하전절대각도적단조변화적시험규률,결합분차이론가이묘술평면응변조건하기선감소연후증대적규률。통과궤충이론대비분석표명,모형결합분차이론불단능구묘술다충응력상태하적평면응변화상규삼축응력조건하전절대각도표현적불동규률,이차능구종세관각도해석기각향이성성인。
Aiming at the test results of shear band angle under plane strain conditions for anisotropy sand,a comparative analysis was carried out based on the three traditional theories and bifurcation theory.The results of shear band under plane strain condition described by the three traditional theories showed the traditional theories could estimate the minimum,middle and maximum values of the shear band angle of sand,whilst it could not t explain the anisotropy behaviors of shear band.The shear band under the plane strain conditions was easily observed,and it induced shear bands that reduced material strength when the directions of shear band and sand deposition were the same.It resulted in the different anisotropy characteristics in the conventional triaxial conditions and plane strain conditions. Such different characteristics could be explained using bifurcation theory together with anisotropy model. With the direction variation of sand deposition,the model ccould explain the monotonic behaviors of shear angled under conventional triaxial condition from microscopic viewpoint,the bifurcation theory combined with the model could describe the behavior of shear angled under plane strain condition which decreased first and then increased.The comparative analysis of four theories showed that bifurcation theory together with anisotropic model well explained the different shear properties between plane strain and conventional triaxial under various stress conditions,and one could well explain it from the microscopic viewpoint.