Junction structure of basement outer wall and foundation pit horizontal brace

The utility model discloses a structure for the junction of a basement outer wall and a foundation pit horizontal support. The structure comprises a horizontal inner supporting beam (600), an inner supporting external expansion ribbing part (1), a water stop steel plate (2) and a basement outer wall embedded steel bar (3), the inner support and outer expansion ribbing part is circumferentially constructed on the horizontal inner support beam, and the inner support and outer expansion ribbing part is located at the junction of the horizontal inner support beam and a basement outer wall (402); the water stop steel plate is arranged between the internal support external expansion ribbed part and the basement exterior wall; the multiple basement outer wall embedded steel bars are embedded in the horizontal inner supporting beams correspondingly, and the two ends of the multiple basement outer wall embedded steel bars penetrate through the inner supporting external expansion ribbing parts and extend into the basem