岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2010年
2期
661-666
,共6页
地表变形%应力路径%本构模型%数值模拟%剪胀%剪缩
地錶變形%應力路徑%本構模型%數值模擬%剪脹%剪縮
지표변형%응력로경%본구모형%수치모의%전창%전축
earth's surface deformation%stress path%constitutive model%numerical simulation%dilatancy%contraction
针对不同环境条件及工程因素对地表变形影响的不同特点,研究了不同应力状态下土的变形特性,得出其影响地表变形的基本规律.通过典型三轴试验对比分析了变形规律,由试验数据空间反演了各应力路径下的本构模型空间,编制相应的模块嵌入有限元程序,模拟了几种不同路径下地表沉降算例,得到了导致地表变形的几个基本规律:①不同的地表变形问题对应的应力路径千差万别,需要用不同的应力路径条件下的本构模型进行分析;②应力路径的影响是不可忽略的,甚至在诸多因素中起主导作用;③数值建模方法建立起来的模型通过权值系列的不同反映应力路径的影响,能较好应用于此类问题的分析;④CTC与TC路径极限体变相差近20 %;⑤CTC路径的剪缩区范围比CTE路径大,两种路径下剪缩体应变值最大相差近17.3 %;CTE路径较CTC路径的剪胀更为明显,剪胀体应变最大相对差值近98 %.
針對不同環境條件及工程因素對地錶變形影響的不同特點,研究瞭不同應力狀態下土的變形特性,得齣其影響地錶變形的基本規律.通過典型三軸試驗對比分析瞭變形規律,由試驗數據空間反縯瞭各應力路徑下的本構模型空間,編製相應的模塊嵌入有限元程序,模擬瞭幾種不同路徑下地錶沉降算例,得到瞭導緻地錶變形的幾箇基本規律:①不同的地錶變形問題對應的應力路徑韆差萬彆,需要用不同的應力路徑條件下的本構模型進行分析;②應力路徑的影響是不可忽略的,甚至在諸多因素中起主導作用;③數值建模方法建立起來的模型通過權值繫列的不同反映應力路徑的影響,能較好應用于此類問題的分析;④CTC與TC路徑極限體變相差近20 %;⑤CTC路徑的剪縮區範圍比CTE路徑大,兩種路徑下剪縮體應變值最大相差近17.3 %;CTE路徑較CTC路徑的剪脹更為明顯,剪脹體應變最大相對差值近98 %.
침대불동배경조건급공정인소대지표변형영향적불동특점,연구료불동응력상태하토적변형특성,득출기영향지표변형적기본규률.통과전형삼축시험대비분석료변형규률,유시험수거공간반연료각응력로경하적본구모형공간,편제상응적모괴감입유한원정서,모의료궤충불동로경하지표침강산례,득도료도치지표변형적궤개기본규률:①불동적지표변형문제대응적응력로경천차만별,수요용불동적응력로경조건하적본구모형진행분석;②응력로경적영향시불가홀략적,심지재제다인소중기주도작용;③수치건모방법건립기래적모형통과권치계렬적불동반영응력로경적영향,능교호응용우차류문제적분석;④CTC여TC로경겁한체변상차근20 %;⑤CTC로경적전축구범위비CTE로경대,량충로경하전축체응변치최대상차근17.3 %;CTE로경교CTC로경적전창경위명현,전창체응변최대상대차치근98 %.
The effect of stress states on the earth's surface deformation is investigated.With clay selected as test sample,deformation rules obtained by a series of classical triaxial compression test under different stress paths.Based on the tests,a numerical constitutive model under different stress paths is derived by numerical modeling method.Moreover,the constitutive model is set in FEA program to simulate earth's surface deformation under different stress paths.By comparison of the cases,some conclusions are drawn as follows:①effects on the earth's surface deformation under different stress paths are different; ②the influences of stress paths should not be neglected in analysis of the earth's surface deformation; ③the constitutive model by numerical modeling method which can reflect the effects of stress paths by using different weights fits for analysis of the earth's surface deformation; ④the maximum volumetric strain ε_(vmax) of path TC is about 20% lower than path CTC; ⑤Shearing dilatancy field of CTE path is larger than that of CTC path while shearing contraction field is smaller.Maximum relative difference of dilatancy volumetric strain between the two paths is about 17.3% whereas maximum relative difference of contraction volumetric strain is about 98%.