Reinforcing system for high-speed railway to pass through expressway in close range

The utility model relates to railway engineering, in particular to a reinforcing system for a high-speed railway to pass through an expressway at a close distance. Comprising an existing expressway bypass diversion section and a newly-built tunnel underpass section reinforcing structure. The newly-built tunnel underneath pass section reinforcing structure comprises a secondary lining, a single-layer primary support, a side wall anchor rod, a first-ring large pipe shed advance support and a first-ring small pipe advance support, and the secondary lining, the single-layer primary support, the large pipe shed advance support and the small pipe advance support are sequentially arranged in a stacked mode. A sprayed concrete layer is arranged on the tunnel face of the newly-built tunnel. The pressure on the pavement of the existing expressway is reduced by detouring and diverting the expressway, and the tunnel is mechanically excavated in combination with a three-step and temporary inverted arch construction method