Abstract:Filter tests on gravelly base soil and the filter are conducted using a new large-scale permeameter. Based on a series of filter tests

the influence of the gravel content in the base soil

the grading and dry density of the filter on the internal erosion resistance has been studied. The results show that: the influence of the filter grading and dry density on the coefficient of permeability of the sample is far less than the gravel content in the base soil. The critical gradient of the sample decreases with increasing gravel content in the base soil and increase with the increasing dry density of the filter. When coarser filters are used the critical gradients are significantly reduced. In order to make sure the effectiveness of the filter.

the grading and dry density of the filter or the controlling constriction size of the filter should be strictly controlled in the actual project.