沥青混凝土在剪胀条件下的水力劈裂模型试验研究

Model test of the hydraulic fracture of asphalt concrete under dilatancy condition

随着沥青混凝土心墙坝坝高的增加,在高压水下心墙是否会发生水力劈裂越来越引起工程界的重视。已有试验表明,沥青混凝土孔隙率很小且沥青不会传递水压力,所以沥青混凝土的水力劈裂一般可以不考虑。但在实际工程中,剪胀会导致沥青混凝土孔隙率的增加,由此是否会引发水力劈裂问题尚不清楚。本文针对某工程进行了孔隙率增大后沥青混凝土的水力劈裂模型试验,结果表明,在孔隙率增大及局部拉应力作用下有发生水力劈裂的可能,说明针对实际工程中沥青混凝土可能发生的缺陷进行水力劈裂论证是必要的。

Along with the increasing height of asphalt concrete core, the problem that of whether hydraulic fracture can occur or not under high hydraulic pressure has aroused the recognition of engineers. Some existing experimental studise indicate that the hydraulic fracturing of asphalt concrete is generally not considered becaues the porosity of asphalt concrete is very small and the asphalt does not transfer water pressure. However, in practical projects, dilatation can lead to relatively large porosity of asphalt concrete. Whether this may cause hydraulic fracturing of not is not clear. In this paper, a hydraulic facturing model test with increased porosity of asphalt concrete is carried out, which aims at some real projects. The test shows that,with the combined effect of the increased porosity and local tensile stress, hydraulic fracturing may occur,which also proves the necessity of this test.