真空预压处理高含水率疏浚泥室内足尺大模型试验研究

Full-scale model test on dredged clay at high water content treated by vacuum preloading

采用真空预压法处理高含水率疏浚泥时,处理过程中疏浚泥将产生大幅度沉降,不可避免地将引起塑料排水板的弯曲,从而影响疏浚泥加固效果。为进一步明确塑料排水板弯曲对真空预压处理疏浚泥加固效果的影响,对塑料排水板联合真空预压处理高含水率疏浚泥开展了室内足尺大模型试验。结果表明:真空预压过程中塑料排水板将产生弯折型弯曲和非弯折型弯曲,且弯折型弯曲出现的位置随真空预压时间的增加逐渐向塑料排水板下部移动。弯折型弯曲的出现将引起排水板不同深度处真空度的较大幅度降低,且深度的真空度降低幅度大于浅部,可达到30%。同时,排水板中第一个弯折型弯曲的出现还将引起疏浚泥泥面沉降量增加幅度的降低,和处理后疏浚泥含水率随深度增加幅度的增大。

For dredged clay treated by the vacuum preloading at high water content,the bending deformation is observed in the plastic drainage board due to the large consolidation settlement of dredged clay,which would weaken the reinforcement effect.In order to further clarify the influence of plastic drainage board bending on the reinforcement effect of vacuum preloading treatment of dredged clay,an indoor full-scale large model test was conducted on plastic drainage board combined with vacuum preloading treatment of dredged clay with high water content.The results show that there are bending curve and non-bending curve in the plastic board during the process of vacuum preloading,and the bending curve would appear gradually to the lower part of plastic drainage board as the vacuum preloading continues.The appearance of bending type bending will cause a greater reduction of vacuum at different depths of the drainage board,and the reduction of vacuum at depth is greater than that at shallow parts,which can reach 30%.Meanwhile,when the first bending curve appeared,the increase in the surface settlement of dredged clay with preloading time begin to decrease,and the increase in the water content with depth for treated dredged clay appears to increase.