CALCULATION FOR DISPLACEMENT AND INTERNAL FORCE OF PILE ANCHOR RETAINING STRUCTURE BASED ON IMPROVED INCREMENT METHOD

At present, the improved incremental method is widespread in the study of the internal force and deformation of the pile anchor retaining structure for deep excavation. The precise calculation of load increment plays a key role in applying this method into practice. Most of the researchers focus on the reaction increment of the soil below the excavated surface and released due to the soil elastic resistance change caused by resistance coefficient change. However, there are few studies on the influencing factors of soil elastic resistance. Therefore, we used the earth pressure considering displacement and considered the influence of the change of the elastic resistance caused by the change of the resistance factor of the soil below the excavation surface. We proposed an incremental calculation method that was more in line with the actual engineering. Then we compiled a MATLAB calculation program based on the engineering example and compared the results of the program with those before consideration. Furthermore, we adopted PLAXIS to simulate the engineering example to verify the rationality of this method. The results show that the calculation method for displacement and internal force of pile anchor retaining structure based on improved incremental method is reasonable and feasible. Finally, we used the method of control variable to discuss two factors that affected the soil elastic resistance—the cohesion of soil and the internal friction angle of soil. The results show that as the decrease of the cohesion of soil and the internal friction angle of soil, the displacement of pile shows a trend of increasing, but the maximum displacement is always within the allowable range of deep excavation deformation.