Design and construction techniques of retaining structures under railways running across foundation pits

The foundation pit of Shanghai South Railway Station is constructed under the condition of running railway across it.During the construction process,some key construction techniques are adopted to ensure the running of the railway without stop and to reduce,decreasing the deformation of the railway subgrade and retaining structures.For continuous construction,many technical measures are used,including subdivision of construction units,available deformation observation et al.The key construction techniques can be adopted by other similar projects.