Research On The Excavation System Stability Under Railway Line In Subsidence Area

The main means of transport of coal in china is still rail transport. Many of the domestic dedicated railway lines happened subsidence deformation alone with the surface deformation which caused by mining coal that under the lines. Culvert was damaged and submerged under normal water level, thus it cannot meet the requirement. In this case, the culvert has to be rebuilt. Therefore, the formula that utilize artificial digging pile and inner supporting to support the excavate system and set the temporary overhead system upon the piles to make sure the normal passage of railway. The key of performed reconstruction culverts under the existing railway line is to provide sufficient working space and to ensure the normal working of railway. This paper researched excavate system in subsidence area the under the above-mentioned engineering background,the main research contents and conclusion are as follows:Firstly, finite difference software FLAC3 D was taken to simulate the excavate system under the railway line in subsidence area. The law of pile force and deform and soil deform were analyzed under different pile depth, excavate width, inner supporting schemes, train loads and excavate potions. The results showed that all the factors above have impacted the piles force and deform and soil deform in varying degrees. Then, the BP artificial neural network was used to predict the pile deform under different conditions by taking the results of numerical simulation as training simple. The results shows that the prediction results are close to the numerical simulation results, which proved the artificial neural network is reliable for predicting in excavate system.Finally, The effect of using of hand-dug pile and inner support in practical project to support excavation system is obvious which ensure the stability of excavation system and the normal traffic. FLAC3D(numerical simulation) and Lizheng deep excavation software(engineering calculation) were used to calculate the actual project, and the results of two methods were contrasted. Taking the earlier research results, optimization scheme was promoted based on the previous scheme; the results suggested that the two methods have consistency in calculate the piles force and deform, however, the numerical simulation has smaller results in analsys the bottom heave and surface deformation. It will be more meaningful to use a variety of calculation methods in design and calculate in the future.