Construction technology of earth pressure balance shield in watery sandy stratum

Considering the engineering case that earth pressure balance shield machine passes through watery sandy stratum 345 m in length,the balance problem of double screw conveyors of the shield machine passing through the sandy stratum with high coefficient is discussed based on the Rankin’s earth pressure theory.The calculated results show that the shield machine has good adoptability to the watery sandy stratum.However,if groundwater infiltration happens,it is possible that inrushing of water and soil will happen,therefore some engineering measures to reduce risk induced by the inrushing of water and soil should be taken.Furthermore,the laboratory modified tests on silty sandy stratum are done.The research results show that the modified effect of bubbles is the best,and high molecule polymerization can be used to avoid spewing accidents.Field monitoring shows that the modified effect of residual soil is good.Finally,the relationship between the incorporation of bubbles and the working parameters of tunneling machine is discussed.