【摘要】 采用堆载法对天然状态下未扰动全风化花岗岩进行现场直剪试验,获得了不同正应力作用下的剪应力-剪应变关系曲线以及法向位移-剪应变关系曲线,对其应力应变关系进行了分析。结果表明,未扰动全风化花岗岩在剪切过程中随着剪应变的不断发展均呈现出不同程度的应变软化,土样所受正应力越大,其峰值剪应力越大。正应力较小时(0 kPa、50 kPa),剪切过程中土样不断向上变形,呈剪胀;随着正应力的增大,土样逐渐从一直剪胀转变为先剪缩后剪胀。对各土样的峰值剪应力-正应力进行线性拟合,得出了该未扰动全风化花岗岩的c、φ值,为边坡稳定分析及设计优化提供参考。更多还原

【Abstract】 The field direct shear test was conducted on undisturbed completely decomposed granite using the method of preloading as vertical reaction. The shear stress-shear strain relation curves and the normal deformation-shear strain relation curves under different normal stress were obtained. The stress-strain relationship was studied. The results revealed that the undisturbed completely decomposed granite soil presented strain softening with the increase of the shear stain during shearing. With the higher normal stress the soil suffered,the peak shear stress was higher. When the normal stress was low(0 kPa,50 kPa),the soil dilated during the whole shear process. However,with the normal stress became higher,the soil presented contraction at the beginning and then turn to dilatancy as the continued shearing. The values of c and φ were obtained by the linear fitting of the peak shear stress-normal stress of each soil specimen. The results could provide a reference to the stability analysis and design optimization of the slope.更多还原