TBM tunnel assembly cavern lining system and construction method

The invention relates to the technical field of underground tunnel supporting, and provides a TBM tunnel assembly cavern lining system and a construction method, and the TBM tunnel assembly cavern lining system comprises a primary supporting structure, a small-section concrete member, an arc-shaped concrete member and a soil and stone backfilling layer. The small-section concrete member is of an arc-shaped arch structure body, the inner diameter D1 of the small-section concrete member is larger than the cutter head diameter D2 of the TBM, and D1-D2 is larger than or equal to 8 cm and larger than or equal to 12 cm. The arc-shaped concrete member and the small-section concrete member are concentrically arranged, the arc-shaped concrete member is attached to the peripheral face of the top of the small-section concrete member, and in the vertical direction, the projection of the small-section concrete member on the ground is located in the projection of the arc-shaped concrete member on the ground; and a soil and