Aiming at the problem of excessive uplift of segment in full-section stable surrounding rock strata,a new type of synchronous two-component grout is developed and applied to a section of Nanjing metro line 6 through the combination of laboratory test and field test,which greatly reduces the uplift of segment and improves the quality of segment assembly.The single-liquid hard grout used in the field is used as liquid A,and the new coagulant is used as liquid B.The influence of liquid B on the properties of liquid A is determined by laboratory test.According to the requirements of slurry gel time,fluidity,compressive strength,and combined with the actual situation on site,the ratio of new synchronous two-component-liquid grout is determined.The grouting effect of the new synchronous two-component-liquid grout is verified by field test.The results show:(1)The gel time of the new synchronous two-component grout can be shortened to 10-30 minutes by mixing 1%-2%of the total mass of liquid A with liquid B.The slurry has good pumping performance and high early strength.(2)The fluidity of the new synchronous two-component grout can not be lost within 10 min after injection,and with good pumping perforrnance and not easy to block the pipe.(3)Monitoring data show that the new synchronous two-component grout has excellent field grouting effect.Compared with the single hard grout,the overall uplift of the segment ring is reduced by 50%,the maximum horizontal deviation of the segment ring is reduced by 57%,the number of leakage points of the segment ring is reduced by 50%,and the maximum surface settlement is reduced by 74.3%.
tunnel engineeringsegment upliftingfield testsynchronous two-component groutgel time
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