【作者】 胡欣；

【导师】 严驰；

【作者基本信息】 天津大学 ， 岩土工程， 2010， 硕士

【摘要】 一般来说,基坑工程是一个涉及岩土,结构,土力学、水文地质、渗流力学、工程地质等多个学科综合性很强的系统工程,所以说无论是在施工技术上还是在理论基础上基坑工程都是一个极其复杂的课题。很重要一点在于基坑工程中的渗流影响,在基坑开挖过程中的地下水的变化直接影响了工程的技术处理以及安全问题。由于许多基坑出现在建筑物密集区,尤其是深基坑的开挖降水,必然会引起周围地下水位的变化,从而导致周围土体不均匀沉降,进而使得周围的建筑物也发生不均匀沉降,严重的可能导致建筑物倒塌,危害人们的生命安全,给社会经济带来不同程度的损失。实际上我们在处理数学模型时不可以设计得简单或是过于理想化,如果这么做那么在计算土层变形时即使我们考虑的相当全面、十分精准也会失去意义。在基坑降水设计工程中我们必须慎重考虑,一是因为降水的效果好坏将会直接引起到基坑的开挖,有可能使基坑结构不稳定,甚至造成坑底突涌的工程事故；是降水也会间接影响到周围建筑物的安全,因为正确处理基坑过程中的降水问题是保证整个工程安全的重要一环。这一切的前提就是对地下水渗流问题进行有效地研究与分析,发现其中的规律,使得整个降水过程既经济又合理,同时提出行之有效的地面沉降控制措施,以保证周围建筑物在基坑开挖过程及使用过程中的安全。研究结果表明,地下渗流场的改变直接导致了基坑周围地面沉降,本文提出的三种控制地面沉降的措施分别为：1.间歇性降水；2.加深止水帷幕；3.布置回灌井；三种措施目的就是控制基坑周围的地下渗流场的改变,从而达到控制地面沉降的目的。实例计算表明,使用三种措施与没有使用任何措施对比之间的地面沉降值发现,三种措施均有不同程度的防治地面沉降的效果,其中各有各的使用特点与优势。所以在采取这些控制措施之后可以很好的解决因基坑降水引起的周围地面沉降的问题,保证了基坑工程的安全性。更多还原

【Abstract】 In general, the Foundation is involved in geotechnical, structural, soil mechanics, hydrogeology, mechanics, engineering geology, and other highly integrated systems engineering disciplines, so that both in the construction of technical or theoretical basis the Foundation is an extremely complex subject. Very important point is that in the seepage flow, the groundwater during excavation changes directly affect the project’s technical processing and security issues.Since many foundation in building-up areas, especially in deep foundation excavation dewatering, will inevitably lead to changes in the surrounding water table, leading to uneven settlement of the surrounding soil, thereby making the surrounding buildings are of uneven settlement, may lead to serious building collapse, endangering people’s lives, to bring different levels of social and economic losses.In fact, we can not deal with mathematical models designed to be simple, or too idealistic, if to do so in the calculation of soil deformation, even if we consider the very comprehensive and very precise meaning will be lost. In the foundation pit design engineering, we must carefully consider, first, because the effect of precipitation will directly lead to good or bad to the foundation excavation, foundation structure is unstable and there may even cause sudden Chung Bottom engineering accident; Second, the precipitation will also indirectly affect the safety of surrounding buildings, as correctly handle the problem of precipitation during excavation to ensure the safety of the whole project an important part. The premise is that all groundwater seepage to research and analysis, and found the law precipitation process economic rationality, Also proposed measures for effective control of land subsidence, Ensure that surrounding buildings in the excavation process and the use of process safety.The results show that changes in underground seepage around the foundation was a direct result of land subsidence, the proposed three kinds of control measures for land subsidence, respectively:1. intermittent precipitation; 2. deepen waterproof curtain; 3. layout recharge; three measures purpose is to control the excavation around underground seepage field changes, which aim to control land subsidence. The example shows that the use of three measures compared with no use of any measures the value of land subsidence was found between the three measures have different levels of control effect of land subsidence, which each have their own characteristics and advantages of the use. So, after taking these control measures can be a good solution for foundation pit around the land subsidence caused by the problem of ensuring the safety of excavation.更多还原