effective mean normal stress

基本解释

The larger the density, the lower the effective mean normal stress, the more dilative response is.
土的密度越大，有效平均正应力越低，土的剪胀性就越大。
Both the strength and dilatancy of sand increase with the density under the same initial effective mean normal stress.
对于初始应力状态相同的砂样，砂土的强度和剪胀性随试样密度的增大而增大；
Whether a sand dilates or contracts depends on the current state of the sand, that characterized by both the density of the sand and the effective mean normal stress applied.
试验结果显示砂土在剪切过程中会产生剪胀或剪缩，其胀缩性由该砂土的当前状态所决定，而砂土的当前状态取决于本身的密度和所施加的有效平均正应力。