海相结构性软土扰动排水试验分析

因天然沉积海相土在扰动下结构性被破坏,土体甚至会变成流态,更易排水,现针对高灵敏度天然沉积海相土“先扰动后排水”的排水固结改进方法,为实现该技术的有效性,通过塑料排水板联合真空预压的模型试验,对比研究了原状土和扰动土采用真空预压处理时固结时间、表层沉降及处理后土体含水率与强度、灵敏度的差别,并对比了原状样和扰动样分别抽真空后的微观结构。试验结果表明,对于天然沉积海相土的原位状态强度较高但土体结构不稳定的特点,采用快速扰动法预先破坏土体结构,可以消除高灵敏度引起的土体结构不稳定问题,在扰动后进行预压处理后,扰动相对于原状含水率降低31%左右,沉降量扰动相对原状提高1倍,排水量也增加了4倍左右,屈服应力和土体灵敏度降低,排水加固效果明显。

Experimental analysis of disturbed drainage of marine structural soft soil

Because the structure of the natural sedimentary marine soil is disturbed under the disturbance, the soil will even become a flow, which is easier to drain, the improved method of drainage consolidation for high sensitivity natural sedimentary Marine soil "first perturbation drainage" ,for effective implementation of the technology, by plastic drainage plate joint vacuum preloading, comparative study of undisturbed soil and disturbed soil pressure when dealing with consolidation time, surface subsidence and treatment of soil water content and the strength and sensitivity of the difference of the vacuum preloading, and the microstructure of undisturbed and disturbed samples respectively after vacuum pumping were compared. The experimental results show that the in situ high strength natural marine sedimentary soil but not stable soil structure characteristics, the rapid advance of soil structure damage disturbance method can eliminate the soil structure caused by high sensitivity the unstable problem in disturbance, preloading drainage, compared with the original condition, the moisture content of the disturbance decreased by 31%, the sedimentation disturbance has doubled compared with the original state and the displacement has increased by about 4 times, and the yield stress and soil sensitivity decreased, reinforcement effect is obvious.