基底减压抗浮技术有限元分析

发布时间：2018-05-18 04:14

本文选题：水浮力 + 抗浮　；参考：《南京工业大学》2013年硕士论文

【摘要】：随着地下空间开发的高速发展，建筑物基础的抗浮问题变得日益突出。抗浮措施不当已造成沿海沿江地区大量建筑上浮倾斜和倒塌的事故，同时抗浮设防水位过高又会造成投资的浪费，因此开展对地下结构抗浮措施的研究工作具有重要的科学意义，其研究成果对于指导优化抗浮设计，减少不必要的资金和材料的投入，确保建筑的安全可靠具有重要的工程意义和广阔的应用前景。通过对资料收集整理，总结了现有的抗浮措施的工程应用和研究现状。现有的抗浮措施抗浮锚杆抗浮、配重抗浮和抗浮桩抗浮都是从增加抗浮力的角度来增加抗浮安全系数，而排水减压抗浮技术是从降低或消除水浮力的角度来增加抗浮安全系数。而且排水减压抗浮技术能够有效减小工程材料的投入，缩短建设工期，具有广阔的运用前景。本研究基于二维岩土工程有限元分析软件Geostudio的渗流SEEP/W模块和Midas/GTS，针对基底减压抗浮技术这种排水减压抗浮措施进行二维渗流分析和沉降分析，并对实际工程的基底减压抗浮技术进行了模拟验证。研究得出基底减压抗浮技术的核心是在底板上均匀布置一定数量的渗流通道，消除作用在建筑物上的水压力，同时利用一定厚度的渗透系数较小的弱透水层和截水帷幕形成有效的隔水层，有效的减小实际的渗流量，从而避免对周围环境产生过大的影响。计算结果表明对抗浮最主要的控制影响因素是弱透水层的厚度和渗透性，，通过对计算数据的回归分析，得到一控制渗流量的拟合公式，公式反映了两者对渗水量的影响的敏感性。通过对不同的土质的数值模拟试验，分析得出在渗透性较小的粉质黏土和黏性土地基中采用基底减压抗浮措施可有效控制周围的地下水和地面沉降的影响，在渗透性较强的砂土的地基，减压抗浮对周围影响较大，而人工设置渗透系数较小的弱透水层同样可以控制对周围环境的影响。
[Abstract]:With the rapid development of underground space, the anti-floating problem of building foundation becomes increasingly prominent. Improper anti-floating measures have caused a large number of accidents in the coastal areas along the Yangtze River to rise, tilt and collapse of buildings. At the same time, too high anti-floating and defensive water levels will lead to a waste of investment. Therefore, it is of great scientific significance to carry out the research on anti-floating measures of underground structures. The research results can guide the optimization of anti-floating design and reduce the unnecessary investment of funds and materials. To ensure the safety and reliability of buildings has important engineering significance and broad application prospects. The engineering application and research status of the existing anti-floating measures are summarized by collecting and arranging the data. The existing anti-floating measures, anti-floating anchor, counterweight anti-floating and anti-floating pile are to increase the anti-floating safety factor from the angle of increasing the anti-buoyancy, while the drainage and decompression anti-floating technology is to increase the anti-floating safety factor from the angle of reducing or eliminating the water buoyancy. And drainage decompression and anti-floating technology can effectively reduce the input of engineering materials, shorten the construction period, and have a broad application prospect. Based on the seepage SEEP/W module of two-dimensional geotechnical engineering finite element analysis software Geostudio and Midas / GTSs, the two-dimensional seepage analysis and settlement analysis are carried out for the drainage decompression and anti-floatation technology of basement decompression and anti-floatation technology. The foundation decompression and anti-floating technology is simulated and verified. It is concluded that the core of the technology is to arrange a certain number of seepage channels on the floor to eliminate the water pressure acting on the building. At the same time, the weak permeable layer with a certain thickness of permeability coefficient is used to form an effective waterproof layer, which can effectively reduce the actual seepage flow, thus avoiding the excessive influence on the surrounding environment. The results show that the most important controlling factors are the thickness and permeability of the weak permeable layer. By regression analysis of the calculated data, a fitting formula for controlling the seepage flow is obtained. The formula reflects the sensitivity of both of them to the water seepage. Through the numerical simulation test of different soil quality, it is concluded that the effect of ground water and ground subsidence can be effectively controlled by adopting subgrade decompression and anti-floating measures in silty clay and clay foundation with less permeability. In the foundation of sandy soil with strong permeability, the influence of decompression and anti-floating on the surrounding environment is greater, but the influence of the weak permeable layer with small permeability coefficient can also be controlled.
【学位授予单位】：南京工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU93

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