Waterproof and drainage structure at top of middle partition wall of multi-arch tunnel and construction method of waterproof and drainage structure

The invention discloses a waterproof and drainage structure at the top of a middle partition wall of a multi-arch tunnel and a construction method of the waterproof and drainage structure. The waterproof and drainage structure at the top of the middle partition wall comprises an initial support of a middle pilot tunnel, longitudinal drainage pipes at shoulder parts of the middle partition wall, awaterproof layer, and longitudinal drainage pipes at arch springs, wherein a circumferential permeable pipe of the middle pilot tunnel is connected with the longitudinal drainage pipes at the shoulderparts of the middle partition wall in a three-way T-shaped connection manner; circumferential drainage blind pipes of main tunnels are connected with the longitudinal drainage pipes at the two shoulder parts of the middle partition wall in a cross-shaped connection manner; the circumferential drainage blind pipes of the main tunnels are connected with the longitudinal drainage pipes at the arch springs in a T-shaped conne