土与混凝土板接触面剪切试验研究

Experimental Study on Shear Tests of Contact Face of Soil with Concrete Slab

通过黏土与混凝土板接触面大型单剪试验和直剪试验,得到应力应变(位移)曲线以及抗剪强度曲线。两种试验的过程中都存在接触面积减小、应力不均匀以及土样实际位移小于所测位移的现象;单剪试验应力应变曲线呈应变硬化型,直剪试验应力位移曲线呈略微软化型;单剪试验的凝聚力大于直剪试验的凝聚力,单剪试验的摩擦角小于直剪试验的摩擦角;作用于结构面上的法向土压力较小时,接触面的破坏发生在土与结构的交界面上,法向土压力较大时,破坏发生在土与结构交界面附近的土体内。因此,在工程设计计算时,应根据情况取用不同的计算参数。

According to the large scale simple shear tests and direct shear tests of the contact face between clay and concrete slabs, the stress-strain curves or stress-displacement curves and shear strength envelope curves were obtained. The phenomenon that the contact area is decreased and uneven stress distribution exist in the process of both kinds of tests. The stress-strain curves of the simple shear tests presented the character of strain hardening, and the stress-displacement curves of the direct shear tests presented the character of softening slightly. The cohesion that obtained by the simple shear tests was harder than the cohesion that obtained by the direct shear tests, but the friction angle of the simple shear tests was smaller than that of the direct shear tests. When the normal soil pressure that distributes on the surface of the structure is low, the failure of the interface will occur on the soil-structure contact surface, and when the normal soil pressure that distributes on the surface of the structure is high, the failure of the interface will occur in soil nearby the soil-structure contact surface. Therefore, different calculating parameters should be used according conditions during engineering design calculates.