Deformation Prediction of Deep Excavation Based on Unequal Interval Grey Model GM(1,1)

The Grey Model GM (1, 1) is extensively used in deformation prediction of deep excavation, which is very important for design and construction of foundation excavation. The Grey Model GM (1, 1) is based on the equal interval data. So it is difficult to predict when the data is unequal. For the shortcoming, the Grey Model GM (1, 1) is improved. The difference which is formed when unequal interval is transformed to interval is adjusted by unit time coefficient. So the unequal interval Grey Model GM (1, 1) is obtained after reversing the equal interval sequence. The deformation prediction is made by a deep excavation in Wuhan, Hubei, China. Through comparison and analysis on the prediction and actual data, it shows that unequal interval Grey Model GM (1, 1) is more closed to the reality.