舟山海相沉积物真空预压排水固结机理与实验研究

发布时间：2018-04-17 06:43

  本文选题：围海造陆 + 海相沉积物　； 参考：《浙江海洋大学》2017年硕士论文

【摘要】：海相沉积物物理化学及力学性态研究是围海造陆工程实践的基础。本文以舟山海相沉积物为对象,通过系统的材料与模型实验研究,探索利用真空预压排水固结技术对围海造陆工程中高含泥量海相吹填泥浆快速处理与加固的机理及工艺,形成的主要研究成果如下:自行研发了一整套用于海相沉积物真空预压排水固结过程模拟的实验系统,主要包括海淤泥浆专用提取器、模块化海淤模型桶、集成式模型槽、可控式真空水气抽滤装置等设备;利用材料物化分析及力学测试,在课题组前期研究基础上,进一步完善了舟山海洋土数据库,相关数据也是本文研究的重要基础;模型实验共设计4套方案:1#方案真空负压直接加载至80kPa;2#方案真空负压按照20kPa、40kPa、80kPa次序做分级加载;1#及2#方案均使用硬胶模型桶模拟吹填泥浆的无侧限应力状态;3#方案真空负压直接加载至80kPa,待海相吹填泥浆沉降稳定时,开膜增做塑料排水板二次插板;4#方案不做二次插板,其它同3#方案;3#及4#方案均使用刚性模块化海淤模型桶,模拟吹填泥浆的侧限应力状态;真空预压排水固结模型实验对吹填泥浆的沉降量、水气排放量、真空负压、孔隙水压、地温等物理力学场做全程监测;预压结束并开膜后,在模型桶内做原位取样,对密度、含水率、抗剪强度等物理力学指标做全场测试,尤其是在3#及4#方案下利用模块化海淤模型桶实现对土样的整体脱模后,执行“外科手术”式的精细化取样及测试;实验、实测结果表明,实验过程中1#、2#桶体径向收缩显著,为典型的无侧限应力状态;3#及4#桶体几乎无径向收缩,故属于侧限应力状态;真空预压排水固结后海相吹填泥浆会形成一表面硬壳层,约为泥浆总厚度的1/3;此后深层泥浆的排水固结效率会衰减,经二次插板后,海相吹填泥浆真空预压排水固结的效率会进一步改善,密度、抗剪强度指标的提高幅度分别为10%及15%,真空预压排水固结在围海造陆工程中的技术潜力仍有挖掘空间。
[Abstract]:The study of physical, chemical and mechanical behavior of marine sediments is the basis of the engineering practice of land reclamation.Taking marine sediment in Zhoushan as an object, through systematic material and model experiment, the mechanism and technology of rapid treatment and reinforcement of marine filling mud with high content of mud in marine reclamation project by vacuum preloading drainage consolidation technology are explored in this paper.The main research results are as follows: a set of experimental systems for simulating the consolidation process of marine sediments by vacuum preloading are developed, including a special extractor for sea mud slurry, a modular sea silt model barrel, an integrated model tank, and an integrated model tank.Based on the material physicochemical analysis and mechanical test, the marine soil database of Zhoushan is further improved on the basis of the previous research of the research group, and the relevant data are also the important basis of this study.Model experiment 4 sets of schemes were designed: 1# scheme vacuum negative pressure direct loading to 80kPa2# vacuum negative pressure step loading according to 20kPa40kPa40kPa sequence and 2# scheme using hard glue model barrel to simulate the unconfined stress state of the blowing mudThe vacuum negative pressure is directly loaded to 80 KPA, and when the marine filling mud is stable,The membrane is added to the plastic drainage board and the second plugging board is not used for the second plugging board. The rigid modularized sea silt model barrel is used in other schemes of the other schemes, and the lateral stress state of the blowing mud is simulated.In vacuum preloading drainage consolidation model experiment, the physical and mechanical fields, such as sedimentation amount, water vapor discharge, vacuum negative pressure, pore water pressure, ground temperature and so on, are monitored in the whole process; after preloading and opening film, the in-situ sampling is made in the model barrel, and the density is measured.The physical and mechanical indexes such as moisture content, shear strength and other physical and mechanical indexes were tested in the whole field, especially after the complete demoulding of soil samples was realized by using modularized sea silt model barrels under the scheme of 3# and 鈪，

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