The invention discloses a
slurry shield split launching construction method for a water-rich sandy gravel stratum. The method comprises the following steps that A, a tunnel portal is sealed to build abin,
grease is smeared on a tunnel portal
brush, the tunnel portal is broken, a shield cutter head is jacked into a tunnel face, the
grease is injected into a short sleeve and a muddy water bin, mudis injected into the muddy water bin, and the pressure is gradually increased to calculated incision pressure; B,
shield tunneling and trolley transfer construction are conducted, a trolley is arranged before shield launching, the trolley is straightened, the tunnel portal is sealed, and the trolley is lowered into a well; and C, secondary switching of the trolley is conducted, outage and pressuremaintaining are conducted,
slurry with the
viscosity of 35-50s and the density of 1.1-1.3g / cm<3> is used, and
permeation is conducted on the tunnel face in a large circulation mode; and
slurry with the
viscosity of 90-120s is injected into the muddy water bin from a central rotation standby uppermost flushing pipeline to replace the slurry in the muddy water bin, and the pressure of the muddy water bin is maintained. The method has the beneficial effects that the process is reasonable, the stability of the tunnel face of the water-rich sandy gravel stratum is guaranteed under the condition ofoutage, the high efficiency of slurry shield split launching is realized, and the cost is reduced.