【摘要】：對(duì)黃河岸灘飽和粉土在固結(jié)不排水條件下進(jìn)行了一系列單調(diào)加載、循環(huán)荷載后單調(diào)加載的三軸試驗(yàn),研究了動(dòng)應(yīng)力幅值、圍壓及動(dòng)孔壓比對(duì)循環(huán)荷載后力學(xué)特性的影響,提出了可考慮圍壓及動(dòng)孔壓比影響的粉土循環(huán)荷載后單調(diào)加載應(yīng)力應(yīng)變關(guān)系的變形模式。試驗(yàn)結(jié)果表明:循環(huán)荷載作用完全液化時(shí),動(dòng)應(yīng)力幅值變化對(duì)液化后力學(xué)特性的影響很小;循環(huán)荷載后單調(diào)加載的有效應(yīng)力臨界狀態(tài)線與單調(diào)加載時(shí)相同,不受循環(huán)荷載作用歷史的影響。與單調(diào)加載時(shí)相比,循環(huán)荷載后的不排水強(qiáng)度及初始切線模量皆產(chǎn)生衰化,衰化程度隨動(dòng)孔壓比的增大而增大,初始切線模量的衰化程度更明顯;不同圍壓下循環(huán)荷載后的不排水強(qiáng)度比、初始切線模量比及破壞比,皆與動(dòng)孔壓比之間有良好的歸一化關(guān)系;粉土循環(huán)荷載后的應(yīng)力應(yīng)變關(guān)系可以用雙曲線模型來描述,模型計(jì)算值與試驗(yàn)實(shí)測值基本吻合。
[Abstract]:A series of triaxial tests of saturated silt on the Yellow River beach under consolidation and undrained conditions were carried out. The effects of dynamic stress amplitude, confining pressure and dynamic pore pressure ratio on the mechanical properties after cyclic loading were studied, and the deformation model of monotone loading stress-strain relationship after cyclic loading of silt considering the effects of confining pressure and dynamic pore pressure ratio was put forward. The experimental results show that when the cyclic load is completely liquefied, the dynamic stress amplitude has little effect on the mechanical properties after liquefaction, and the critical state line of effective stress after cyclic loading is the same as that under monotone loading, which is not affected by the history of cyclic load. Compared with monotone loading, the undrained strength and initial tangent modulus after cyclic loading decay, the degree of decay increases with the increase of dynamic pore pressure ratio, and the decay degree of initial tangent modulus is more obvious, and there is a good normalization relationship between undrained strength ratio, initial tangent modulus ratio and failure ratio after cyclic loading under different confining pressures. The stress-strain relationship of silt under cyclic loading can be described by hyperbolic model, and the calculated values of the model are in good agreement with the measured values.
【作者單位】： 西安理工大學(xué)巖土工程研究所;恒大地產(chǎn)集團(tuán)石家莊有限公司;
【基金】：國家重點(diǎn)基礎(chǔ)研究發(fā)展計(jì)劃(973計(jì)劃,2011CD403305) 陜西省教育廳省級(jí)重點(diǎn)實(shí)驗(yàn)室重點(diǎn)科研資助項(xiàng)目(2010JS086)
【分類號(hào)】：TU411

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