Abstract：A new type of composite building enclosure is applied to deep excavations recently，which is composed of soil nailing and cast-in-pile. A finite element software is used to analyze this new kind of building enclosure and make a detailed comparison between the measured stresses and in-situ displacements. The interaction of these two parts of the enclosure is also analyzed；and some useful results on the interaction of these two parts are derived from the numerical analysis. Based on the comparison results，the elastic modulus of some given stiff clay in finite element analysis for excavation is suggested based on the laboratory test. In the designing procedure of this type of composite building enclosure，some practical methods are also recommended.
