【作者】 冯俊福；

【导师】 龚晓南； 俞建霖；

【作者基本信息】 浙江大学 ， 岩土工程， 2004， 硕士

【摘要】 软土地区的深基坑支护结构设计是一个十分复杂的工程问题，由于弹性地基梁法具有计算模式明确、计算过程简单的优点，尤其是m法较符合软土基坑工程的实际情况，因而受到广大工程设计人员的欢迎，大多规范也推荐此法。但是m法计算参数的选取是工程界的一大难题，一般规范都给出了m值的大致范围，而且每个地区的地质条件千差万别，因而m的取值具有很大的随意性，有必要根据一个地区的工程实测资料对m值进行反演分析，以便为地层相近或附近地区的基坑工程设计提供参考和依据。 首先简单的介绍了反分析方法的研究近况及发展过程，对反分析方法的发展做了简要的概括。 其次介绍了杭州地区近年来基坑工程发展的情况，以及基坑围护结构的常用类型。介绍了我国m值的由来，对规范推荐的m法进行了详细的阐述。 然后，利用编制的m法反演分析程序，分析了m值对围护结构内力和位移的影响，计算了内支撑不同设置深度对围护结构内力和位移的影响，分析了反演参数个数对反演优化值的影响，即对解的适定性问题进行了讨论。 最后，根据杭州地区基坑工程实例的位移实测数据，对典型土层m值进行了反演分析，得到了比较适合杭州地区土层的m值。得到一些有益的结论，可供工程设计应用。更多还原

【Abstract】 Foundation structure design in soft soils is a very difficult engineering problem.The elastic foundation beam method has some merits such as easy calculation pattern and definite model and m-method is fit to practical situation, so it is used comprehensively and welcome by constructors,thus m-method is recommended by many Codes.But it is difficult to select a m-value to some soils,and the Codes provides a scope of m-values,and they are different in varied regions and soil conditions,thus it is optional to choose m-value of a soil layer for engineering designers.So it is necessary to calculate m-values by back-analysis method using measured datu of deep foundation pit.For this purpose, this paper first gives a description of recent research advances and a brief introduction of back-analysis method.Second, the development of ditches excavation in Hangzhou is introduced and some often used types of the exterior-protected structures are illustrated. And m-method is stated in detail recommended by the Code.Then,the effects of the inner force and displacements of the exterior-protected structures influenced by the value of M and the different depths of inner poling are analysed with the M-Method back-analysis programme. And the variation of optimized values caused by the numbers of different inversion parameters is also analysed,and a conclusion is drawn that a propriate parameter numbers should be in use of back analysis.Finally, based on some measured datu, the sutable values of M for Hangzhou Region is obtained and some useful conclusions are drawn for constructors.更多还原