数值分析在基坑复合土钉墙支护中的应用

Application of numerical analysis in foundation pit with compound soil nailing support

数值分析方法在岩土工程界有着非常重要的地位,专门的岩土力学有限差分计算程序—FLAC更是有着广泛的应用。目前,复合土钉墙支护在基坑工程中采用已越来越广泛,但其现有理论和方法还不够成熟。本文阐述了该支护方法的主要特点及设计方法。运用FLAC建立基坑复合土钉墙支护模拟模型,该模型可以对预应力锚杆复合土钉墙支护结构进行开挖支护施工过程的二维动态模拟分析,通过数值分析,得到了基坑水平位移、竖直沉降、土钉与锚杆的轴力及位移、土体应力应变的分布曲线。结合实际工程所测得到的数据,将模拟数据与所测数据进行对比分析,说明了运用FLAC建立的二维数值模拟分析模型,能够反映复合土钉墙支护的基坑在开挖支护过程中的受力与变形特征。这也为基坑复合土钉墙支护技术的设计与施工提供指导,并对深入了解复合土钉墙支护作用的机理有较大的现实指导意义。

The numerical analysis method has a high position in the geotechnical engineering field, the specialized finite different computer codes for geomechanics applications has an extensive application more. Currently, the compound soil nailing support for foundation pit have been more and more extensive adopted, but the existing theories and methods are not mature enough. The main eharaeteristic and the design processes of this method are described in this paper. FLAC was employed to establish a model to simulate the foundation pit compound soil nailing support, the model simulates and analyzes the process of exeavation discharge dynamically by the prestressed anchor-compound soil nailing support, through the numerical analysis,the distribution rules of horizontal displacement, vertical settlement,axial force and displacement of anchor and soil nailing, stress-strain of soil mass were obtained. The results of simulation were compared and analyzed with the actual results which were obtained by a practical engineering. The model established by FLAC could reflect mechanics and distortion characteristics of foundation pit. It is helpful to design and construction of the compound soil nailing support.