砂土与混凝土接触面力学特性大型单剪试验研究

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。

LARGE-SCALE SIMPLE SHEAR TEST ON MECHANICAL PROPERTIES OF INTERFACE BETWEEN SANDY SOIL AND CONCRETE FACE

A series of shear tests of interface between sandy soil and concrete face was performed by developed large-scale simple shear apparatus,and the effect of different single grain sandy soil on mechanical properties of interface was studied.By the analysis of test results,the interface thickness and shear displacement of different single grain sandy soil were presented when the sample destroyed.It was shown that there was good linearity of shear strength and normal stress.In the vertical stress at lower,relation curves of the shear stress and displacement showed strain softening;with the increase of vertical stress,the trends of relation curves of the shear stress and displacement showed more obvious,at this time,relation curves of the shear stress and displacement of interface between different single grain sandy soil and concrete face could be seen as being composed of a curve and a flat line.Lower the vertical stress dilatancy more obvious;with the increase of vertical stress,shear dilatancy weakened,and shear stress was gradually increasing when shear dilatation appeared.