排水距离对重塑黏性土一维压缩特性的影响

Effect of Drainage Distance on One-dimensional Compressibility of Remolded Clay

以河南某地饱和重塑黏性土为研究对象,利用改装的固结仪,分别对不同高度的试样进行了固结试验,研究了排水距离对饱和黏性土一维压缩特性的影响.试验表明,单面排水试验中测得的试样不排水面处的孔隙水压力并没有在加载的瞬间达到最大值,且达到按Casagrande作图法确定的主固结完成时间时,试样中仍存在一定的孔隙水压力有待消散.而且,排水距离对饱和土的固结特性和流变特性有着显著的影响.在相同的固结压力作用下,当排水距离较短时,固结系数随排水距离的增大而略微减小,当排水距离较大时,固结系数则随排水距离的增大而明显增大;但次固结系数与排水距离的关系则正好相反.

In the paper,the oedometer tests of the saturated and remolded clay of Henan were carried out on the specimens of different heights by using the modified consolidation apparatus,and the effect of drainage distance on the one-dimensional compressibility of saturated clay was studied.The experimental results showed that,under the oneway drainage,the pore water pressure at the undrained surface of the tested specimen didn’t reach the maximum value at the moment of loading,and it did not dissipate completely at the completion time of the primary consolidation determined by the Casagrande method.Moreover,the drainage distance had a significant effect on the primary and secondary consolidation characteristics of saturated soil.Under the same consolidation pressure,we found the coefficient of consolidation decreased slightly with the increased of the drainage distance for the case with the shorter drainage distance,and it increased obviously with the increased of the drainage distance for the case with the larger drainage distance.The relationship between coefficient of secondary consolidation and drainage distance was opposite.