含石量对碎石土工程特性的影响试验研究

Experimental study on effect of stone content on engineering performance of crushed stone soil

以田师府—桓仁客运专线大前石岭隧道边坡碎石土为研究对象,在通过室内常规物理力学试验获得该碎石土的基本物理性质的基础上,采用大型直剪仪对三组不同含石量的碎石土重塑样进行了剪切试验。试验结果表明：随着含石量的增加,抗剪强度增大;内摩擦角随着含石量的增加而增大,含石量为30%～50%时增幅较快,含石量超过50%后,增幅较慢且呈现逐渐稳定的趋势;黏聚力随着含石量的增大先略微下降后急剧上升,在含石量为50%时最低,而后又急剧升高。碎石土的抗剪特性不同于一般岩土体,含石量对碎石土的抗剪强度影响很大。

The research objective is the crushed stone soil in the slope of Daqianshiling Tunnel in the Tianshifu- Huanren passenger dedicated railway. The basic physical properties of crushed stone soil were tested in lab. The shear test of three groups sample with different stone content was conducted by using the indoor large direct shear tests. The test results show that shear strength increases with the stone content. The internal friction angle increases as the stone content goes up;in particular, the increase rate is the largest when the stone content is 30% through 50%, and then the rate decreases gradually. As the stone content increases, the cohesion initially decreases slightly, then drastically increases. The cohesion reaches its lowest and then rises up drastically. The shear performance of the crushed stone soil is different from other soil, and the stone content has a significant effect on the shear strength.