EXPERIMENTAL STUDY ON COMPRESSIVE MODULUS OF METRO SHIELD GENERATION ZONE IN KUNMING CUMULOSOLS

In the construction process of city metro shield, the ground surface subsidence is one of the most important engineering problems, which not only affects the safety of the subway tunnel construction, but also directly relates to the normal operation of the surrounding buildings. The compressive modulus of generation zone is one of the key shield parameters that control the ground surface subsidence, especially to the shield tunneling in soft soil zone. The mixing proportion of the generation zone grouting material and the soil, and the waiting time after grouting are the important factors that affect the compressive modulus. This paper is based on the cumulosol shield tunneling project of Kunming Metro Line 3 Shiju section, with a compressive modulus test of mixtures which have different proportions of grouting materials and cumulosol and different curing times. The reasonable proportion relationship between the shield generation zone paste in the cumulosol zone and the soil are explored. The time to get expected compressive modulus of generation zone after grouting is put forward, which can provide reference for the shield tunneling construction in the cumulosol area.