裂缝对电渗模型尺寸效应影响的试验研究

通过对电渗-堆载模型试验、单纯电渗模型试验和现场试验的比较发现：裂缝发展的巨大差异是导致单纯电渗模型试验与现场情况差别较大的原因,适当的堆载可消除几何边界引起的尺寸效应,使试验裂缝开展较准确地反映了现场电渗的真实情况,其结果可更好地模拟现场电渗情况;消除尺寸效应后,影响电渗排水效果的主要因素是有效电场面积,电流密度仅为次要影响因素,在梅花形、长方形与平行错位三种布置形式中,有效面积占比最大的梅花形布置效果最优、经济性最好,建议实际工程中采用梅花形布置。

Experimental research on influence of cracks on size effect of electro-osmosis model

In order to study the size effect, a model experiment on the electro-osmosis combined with loading is designed and conducted. Through the comparison among model experiment on electro-osmosis combined with loading, model experiment on simple electro-osmosis and in-situ experiment on electro-osmosis, it is demonstrated that the large difference of cracks is the main reason why the model experiment on simple electro-osmosis draws an opposite conclusion with the in-situ experiment. The size effect caused by geometric boundary can be eliminated by reasonable loading, which makes the cracks similar to those in the in-situ experiment, so the model experiment on electro-osmosis combined with loading can better simulate the in-situ experiment. As the size effect is eliminated, the main factor influencing the electro-osmosis dewatering is the effective electric field rather than the current density. Among hexagonal, rectangular, and parallel and transposition configurations, the hexagonal configuration which has the maximum area of effective electric field is the most effective and economical, so it is recommended to be employed for electro-osmotic treatment.