工程泥浆自重固结及低位真空加载过程的大型模型试验研究
Large-scale model test investigation on self-weight consolidation and low vacuum loading process of construction waste slurry
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摘要: 针对杭州某工地产生的高含水率工程泥浆,以大型地基与边坡工程模型试验装置为实验平台,对工程泥浆的自重固结及低位真空加载过程展开了大型模型试验研究,探讨了该过程中泥面的沉降规律和孔压的发展规律,以及低位真空加载后工程泥浆含水率的大小。结果表明:经过自重固结及低位真空加载两阶段处理,工程泥浆的平均沉降量达314 cm,平均含水率从255.6%降低至115.9%,平均孔隙比从6.72降低至3.04,体积减量达47.6%,这表明低位真空加载处理工程泥浆具有一定的工程可行性;在泥浆的低位真空加载过程中,真空压力从土工布以下的砂垫层传递至泥浆层时出现“孔压突降”的情况;低位真空加载方式可较好的加固底部泥浆,后续应重点关注上部泥浆的脱水处理。Abstract: In view of the high water content of construction waste slurry produced by a site in Hangzhou, with large foundation and slope engineering model test apparatus for experimental platform, the self-weight consolidation and low vacuum loading process of construction waste slurry are investigated experimentally, the variation of slurry surface settlement and the development of pore water pressure in the this process are studied, and the water content of slurry after low vacuum loading is also discussed. The results show that after self-weight consolidation and the low vacuum loading process of slurry, the average settlement reaches 314 cm, the average water content decreases from 255.6% to 115.9%, the average void ratio decreases from 6.72 to 3.04, and the volume reduction reaches 47.6%. These results indicate that the low vacuum loading treatment of slurry has certain engineering feasibility. During low vacuum loading process of slurry, the "vacuum pressure drop" occurs when the vacuum pressure is transferred from the sand cushion under the geotextile to the slurry layer. The low vacuum loading method can strengthen the bottom slurry well, and the following step should focus on dewatering treatment of the upper slurry.