Influences of efficient transport technology of earthwork on operating railways and deformation of excavations using top-down method

The deep excavation of Metro Line No. 15 of West Shanghai Railway Station traverses Shanghai-Nanjing Railway. By using top-down method, deformation control of railway subgrade and diaphragm walls are highly demanded. Construction environment of this excavation is complex. Besides difficult excavation and transport of soil, its efficiency is low. During excavation, creep behavior is obvious in soft soil, so improving the construction efficiency will decrease diaphragm walls deflection caused by soil creep and lower the risk during construction. A soft soil creep model is adopted to simulate the effects on deflection behavior of high-speed railway and diaphragm walls with different conveying efficiencies in this excavation. The results show that, the maximum horizontal displacement of retaining structures decreases by 15% and the maximum settlement of roof decreases by 20% when the conveying efficiency is improved by 30%. |