Tunnel portal structure for super-large-diameter shield mechanical method connection channel and construction method

The invention discloses a tunnel portal structure for a super-large-diameter shield mechanical method connection channel and a construction method, and the tunnel portal structure for the super-large-diameter shield mechanical method connection channel comprises a tunnel portal area duct piece and a non-tunnel portal area duct piece, the tunnel portal area duct piece comprises a tunnel portal non-cutting part, a tunnel portal machinable part, a double-layer embedded steel ring and a shock isolation mechanism. According to the method, the double-layer embedded steel rings are connected to the framework in the non-cutting part of the tunnel portal, the shock isolation mechanism is fixed between the double-layer embedded steel rings, flexible joint connection is adopted, the shock load in the main tunnel is eliminated through the shock isolation mechanism, and the bearing performance and the energy dissipation and shock isolation performance of duct pieces in the region of the tunnel portal are improved; and fat