Research On Foundation Dewatering Technology Of Shang-zhou Phase ? Project Highway Under-passing Existing Railway

With the continuous promotion of the density of our national highway and railwaynetworks, the cross between this two means of transportation has gradually increased.The highway under-crossing existing operating railway engineering means theconstruction of new cross between highway and existing railway needs to be completedby measures under the condition of normal operation of existing railway. Suchengineering has the features of general highway and its own particularity. Theprominent contradiction is the conflict between the safety of highway constructionregion and safe operation of existing railway line. Under the highway through theexisting railway excavation and precipitation during construction will have a impact onthe existing railway embankment and the train operator safety. Therefore, highwaycrossing under the existing railway construction cause the deformation of subgrade hasgreat practical significance, meanwhile precipitation jobs and excavation pit duringconstruction will be of the railway embankment subsidence and deformation caused byvarying degrees of impact.The paper combines the practices of Shang-Zhou Phase ?engineering of highwayunder-crossing jacking LongHai Railway engineering, combining the relevant crossingengineering and underground engineering research, systematically collects the data ofsimilar engineering and related researches to the following research:(1)The paper combining with the actual geological and hydrological data, used?Great Well Method?to design the foundation excavation and draw up an initial dewatering scheme, meanwhile according to soil parameters draw up the scheme offoundation pit excavation.(2)The paper used finite element analysis software MIDAS to construction ofprecipitation in different precipitation rate causing railway subgrade ettlement anddeformation carry on numerical analysis, to clear the optimal deceleration rate andreduce the impact on the railway embankment settlement. According to the results ofthe analysis put forward railroad embankment reinforcement and assurance the normaloperation of the existing lines.(3)The paper used finite element analysis software MIDAS to the foundation pitexcavation carry on numerical analysis. Analysis of foundation pit excavation causingrailway subgrade deformation?to ensure that the rationality of foundation pit excavationand the normal operation of the existing lines.(4)The paper used finite element analysis software MIDAS to precipitationsuddenly stopped excavation construction carry on numerical analysis, dewatering stopsuddenly which causes the increasing of pore water pressure, and the soil rebound offoundation pit, and also pit collapse in severe. Therefore?put forward electricityemergency plan of corresponding precipitation well according to the simulation results.(5)Detailing the actual construction of The highway under-crossing existingoperating railway engineering to clear the importance of construction safety.