Research On Prediction Of Deformations In Composite Soil Nailing Wall Based On BPN

Recently with the development of technology of supporting structure in deep excavations, the method of design of foundation pits has transformed from the pure strength and stability control to strain control and strain prediction analysis should be taken prior to strain control. That is to make prediction of strain tendency and arrange of strain based on the design condition of the supporting structure. Compared to other supporting patterns, the strain of composite soil nailing wall was affected by many factors, so it's very hard to build dynamic model, make predictions of the strain and compute the strain with the method of constitute relation. On account of the highly linearity and uncertainty of the relation between the strain of composite soil nailing wall and the affecting factors , using the artificial neutral network method with characteristics of stronger adjustability, nonlinearity, learning function and fault-tolerance make the strain predictions a available method.The thesis analyzed the latency affecting factors of horizon displacement of composite soil nailing wall, and then make statements of the principles of BP neutral network computing method first. Secondly the thesis analyzed the statistics of 14 projects which are using composite soil nailing wall as supporting structure. Based on the statistics of 30 deep excavation supporting system, we make the training and prediction specimen, and then build the horizon displacement prediction model of composite soil nailing wall with the method of BP neutral network .The thesis also studied the prediction of horizon displacement of composite soil nailing wall supporting structure by comparing the prediction results and the measure results of the specimen(consisted of the statistics of 6 deep excavation supporting structure ).It concluded that the neutral network model has good precision and availability, and it can be taken into the prediction of horizon displacement in the deep excavation supporting system using composite soil nailing wall to support.