Stability Of Channel-Steel-Piles Composite Soil Nailing

Channel-steel-pile composite soil nailing (CCSN) is a new bracing structure of foundation pit, which was developed by Cai Changbin in 2000. In recent years, CCSN has been used widely in the region of Wenzhou, Taizhou...etc, and has obtained good economic performance and social performance. But up to now the CCSN's work mechanism and stability study is a blank. There are no calculation analysis methods for CCSN and the design of it main depends on experience. The behind schedule theories research obstructs the CCSN's further development.On the soil nailing and compound soil nailing research foundation, according to CCSN present research condition and the engineering effective demand, the stability of CCSN is studied systematically by methods of theories research, orthogonal experiment research and case research. Some beneficial results of the CCSN's mechanism and behaviors are gotten and the analysis model and method of CCSN's stability are established. Main research contents as follows:1. Producing and development of CCSN are introduced. The advantage and the localization of the CCSN are pointed out.2. The conformation, craft, construction organization of CCSN, the measure of foundation pit safety and quantity guarantee are summarized.3. Studied the work mechanism of CCSN, the model of stability analysis of CCSN is established and examined by analysis engineering case.4. The orthogonal experiment method is applied in the analysis of foundation pit. Some factors, which influence the stability of CCSN, are studied and sensitivity rules of each factor are gotten. The studied factors respectively are: length of soil nailing, insert deepness of piles, friction force of soil nailing interface, declination angle of soil nailing, horizontal spacing of soil nailing, rows of soil nailing, unit weight of soil, friction angle, unit cohesion, overload of slope, diameter of soil nailing.5. The behaviors of CCSN are studied, and the optimizing of CCSN's designed parameter is analyzed. The suggestions of CCSN's designed parameter are brought upped.6. The method of stability analysis of CCSN is established and the software of the method, which is named MGZS, is developed. An engineering case is analyzed by the method.