利用研制的大型单剪仪,进行砂土与混凝土接触面单剪试验研究,研究单一粒径的砂土对混凝土接触面物理力学性质的影响。从试验结果分析得到,不同单一粒径砂土的接触面厚度和试样破坏时的剪切位移。试验表明:抗剪强度与法向应力呈较好的线性关系;在接触面法向应力压力较低时,剪切应力-位移关系曲线呈应变软化型;随着接触面法向应力的增高,剪切应力-位移关系曲线呈应变硬化型的趋势越明显,此时,不同单一粒径的砂土与混凝土界面剪应力-位移曲线可看成由一条曲线与一条平直线组成。接触面法向应力越低剪胀越明显;随着接触面法向应力的增大,剪胀性减弱,试样发生剪胀时的剪应力也逐渐增大。 The shear test of the contact surface between sand and concrete was carried out by using the developed large single shears, and the influence of single particle size sand on the physical and mechanical properties of concrete contact surface was studied. From the analysis of the test results, the contact surface thickness of different single-size sand and the shear displacement when the specimen is damaged are obtained. The results show that the shear strength and the normal stress show a good linear relationship. When the normal stress of the contact surface is low, the shear stress-displacement curve shows strain softening. With the increase of the normal stress of the contact surface, The trend of shear stress-displacement curve is strain hardening. The shear stress-displacement curve of sand and concrete with different single grain sizes can be regarded as a curve and a flat line. The lower the normal stress of the contact surface, the more obvious the dilatancy. With the increase of the normal stress on the contact surface, the dilatancy decreases, and the shear stress increases when the specimen dilates.