A thin-covering anti-soil-backing drag reduction measure for a rectangular tunnel comprises the following steps: 1, conducting water injection loading on an oil drum in the
tunneling direction of therectangular tunnel; 2, drilling holes in the
tunneling direction of the rectangular tunnel and injecting water; 3, downwards prefabricating concrete retaining blocks in the
tunneling direction of therectangular tunnel; and 4, grouting at intervals. By the adoption of the technical scheme, the measure has the beneficial effects that the soil backing phenomenon occurring in the tunneling process ofa rectangular
shield tunneling machine is reduced to the minimum through measures such as drilling hole and water injection and ceaseless anti-friction mud injection. The rectangular shield tunnelingmachine capable of discharging soil at the top is used, a hard soil layer cannot be formed at the tops of the rectangular
shield tunneling machine, a
pipe jacking
machine and an annular
pipe joint, and the soil backing problem is fundamentally solved.