An improved ground surface access assembly frame

A ground surface access assembly (10, Figure 1), preferably a manhole, comprising a support frame (12, Figure 1) surrounding and defining an aperture and a cover member 16 that seals the aperture. The support frame (12, Figure 1) has a sleeve 14 that extends downwardly to join an inclined sidewall 46, preferably inclined at an angle of 10-60 degrees, which further extends downwardly to join a base plate/flange (26, Figure 1). The base plate/flange (26, Figure 1) has a series of substantially flat valley portions 26a each of which is separated from an adjacent valley portion 26a by an intermediate upstanding crest 80. Each crest 80 has two angled planar surfaces 84a, 84b which may be mutually inclined at an obtuse angle between 100-170 degrees and are connected by a peak 86 that may be curved. The angled planar surfaces 84a, 84b are integrally connected to the inclined sidewall 46. Reinforcement gussets 44 may extend downward from the sleeve 14 and inclined sidewall 46 to the peak 86 of the crests 80. The underside of each crest 80 may have a corrugated surface (88, Figure 11) located within recesses (90, Figure 11).