秸秆体系在真空预压排水下数值模拟及工程应用

发布时间：2018-05-15 19:02

本文选题：吹填土 + 秸秆　；参考：《安徽理工大学》2017年硕士论文

【摘要】：随着加大沿海开发的进程,在沿海软土地区工程建设中,处置浮泥,流泥状超软土的问题很常见,新近吹填土多为浮泥～流泥状超软土,承载力几乎为0,人员和机械设备无法进场。面对如此超软土地基,常采用浅层加固后再深层处理的方法。浅层加固常采用自然晾晒法、化学固化法、真空预压法等。后期深层处理常采用打桩或深层搅拌法。另一方面,农村农作物秸秆的处置问题已成为我国大气环境保护亟需解决的难题。基于上述因素,提出将传统真空排水固结法中的砂垫层及塑料排水板用废弃的秸秆作为排水材料代替。以棉花秸秆和东台工程中产生的超软土为研究对象,基于室内试验、模型试验基础上,再进行数值模拟分析、现场试验等手段,对秸秆的渗透性能、新型秸秆排水系统固结处理超软土的处理效果及影响因素进行了的研究,提出了完整的应用技术,本文研究成果简述如下:(1)通过秸秆捆固结排水性能的模型实验和数值模拟实验研究,揭示了秸秆捆直径、密度、间距、排列方式对固结排水效果的影响规律。(2)通过运用ABAQUS有限元软件进行数值模拟分析,对新型秸秆排水系统关键设计参数的性能进行仿真研究。通过明确秸秆捆的直径、密度、间距、井径比、排列方式等因素对固结排水效果的综合影响规律,通过计算得出,影响固结排水效果的主要因素为秸秆捆的直径和秸秆捆之间的间距。(3)基于现场应用研究,自行研制了便利高效地秸秆捆制作设备,提出了秸秆捆制作与打设、秸秆毯制作与铺设,真空排水辅助系统连接,密封膜铺设等工序的施工方法,最后形成了完整的新型秸秆排水系统固结处理高含水率超软土的施工工艺。(4)通过现场试验,验证了新型秸秆排水系统处理浮泥、流泥状超软土的效果。同时,从经济、技术、社会效应等方面证明了新型秸秆排水系统固结高含水率吹填土应用技术比设计资料中采取的晾晒+掺灰+碾压回填法更为优越,具有良好的社会效应和应用前景。
[Abstract]:With the process of increasing coastal development, in the construction of coastal soft soil area, the problem of disposal of floating mud and flowing mud super soft soil is very common, and most of the newly blown fill soils are floating mud to flowing mud super soft soil. Bearing capacity is almost zero, personnel and mechanical equipment can not enter the field. In the face of such super soft soil foundation, shallow layer reinforcement and deep treatment are often adopted. Natural drying, chemical curing, vacuum preloading and so on are often used in shallow layer reinforcement. In the later stage of deep treatment, piling or deep mixing is often used. On the other hand, the disposal of crop stalks in rural areas has become a difficult problem to be solved in China's atmospheric environment protection. Based on the above factors, the sand cushion and plastic drainage board in traditional vacuum drainage consolidation method are replaced by waste straw as drainage material. Taking the super soft soil produced by cotton straw and Dongtai engineering as the research object, based on indoor test, model test, numerical simulation analysis, field test and other means, the permeability of straw was studied. The treatment effect and influencing factors of consolidation treatment of super soft soil by new straw drainage system were studied, and the complete application technology was put forward. The research results of this paper are summarized as follows: (1) the diameter, density, spacing of straw bundles are revealed through model and numerical simulation experiments on the consolidation and drainage performance of straw bundles. The effect of arrangement on consolidation and drainage effect. (2) the performance of key design parameters of new straw drainage system was simulated and analyzed by using ABAQUS finite element software. By clarifying the comprehensive influence law of the diameter, density, spacing, well diameter ratio and arrangement of straw bundles on the consolidation and drainage effect, it is obtained by calculation, The main factors affecting the consolidation and drainage effect are the diameter of straw bundles and the spacing between straw bundles. Based on the field application research, a convenient and efficient equipment for making straw bundles is developed, and the making and setting of straw bundles are put forward. The construction methods of straw blanket manufacture and laying, vacuum drainage auxiliary system connection, sealing membrane laying and so on, finally formed a complete new straw drainage system consolidation and treatment of super soft soil with high moisture content. The effect of the new straw drainage system on the treatment of floating mud and fluid-mud super soft soil was verified. At the same time, from the aspects of economy, technology and social effect, it is proved that the application technology of new straw drainage system with high moisture content is superior to the method of drying, mixing ash and rolling compacted backfill in the design data. It has good social effect and application prospect.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU472.33

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