【摘要】：非飽和土本構(gòu)關(guān)系模型通常是建立在修正劍橋模型的基礎(chǔ)上,并采用了廣義的von Mises準(zhǔn)則,以描述非飽和土在一般應(yīng)力狀態(tài)下的本構(gòu)行為。該準(zhǔn)則假設(shè)在π平面上屈服面是個圓形,高估了土體除三軸壓縮以外的強度,在平面應(yīng)變中也會錯誤估計中主應(yīng)力比。空間滑動面破壞準(zhǔn)則(SMP)考慮了第三應(yīng)力不變量的影響,屈服面在π平面上為曲邊三角形,可以較好地描述一般應(yīng)力狀態(tài)下土體的剪切屈服和破壞特性。采用變換應(yīng)力方法,將SMP準(zhǔn)則應(yīng)用到最近建立的非飽和土耦合本構(gòu)模型中使其合理的三維化,能夠有效地將模型從軸對稱應(yīng)力狀態(tài)擴展至一般應(yīng)力狀態(tài)。根據(jù)與試驗結(jié)果對比表明,改進(jìn)后的模型在不增加任何參數(shù)的情況下,能夠較好地模擬非飽和土在三軸伸長等一般應(yīng)力狀態(tài)下的行為特性。
[Abstract]:The constitutive relation model of unsaturated soil is usually based on the modified Cambridge model and the generalized von Mises criterion is adopted to describe the constitutive behavior of unsaturated soil under general stress state. The criterion assumes that the yield surface on the 蟺 plane is a circular one, which overestimates the strength of the soil except for triaxial compression and misestimates the principal stress ratio in the plane strain. The effect of the third stress invariant is taken into account in the failure criterion of spatial sliding surface (SMP). The yield surface is curved triangle in 蟺 plane, which can describe the shear yield and failure characteristics of soil under general stress state. By applying the SMP criterion to the recently established coupled constitutive model of unsaturated soil, a reasonable three-dimensional method is proposed, which can effectively extend the model from axisymmetric stress state to general stress state. The comparison with the experimental results shows that the improved model can simulate the behavior of unsaturated soil under general stress state such as triaxial elongation without adding any parameters.
【作者單位】： 中國科學(xué)院武漢巖土力學(xué)研究所;巖土力學(xué)與工程國家重點實驗室;桂林理工大學(xué)土木與建筑工程學(xué)院;
【基金】：國家自然科學(xué)基金項目(11072255,11302243) 廣西自然科學(xué)基金重點項目(2011GXNSFE018004)
【分類號】：TU43

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

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本文編號：2372691