upper edge of the keeper walls just as they were for the split ring cover support described above fig1 depicts a typical expandable joint suitable for placement at j1 j4 the opposing ends 134 of the base portion 112 with the keeper walls 114 and flanges 116 integral therewith are interconnected by spreader means depicted here as a turnbuckle 118 as in the case of the split ring cover support described above the turnbuckle is oppositely threaded into the receiver portions 122 and 122 39 of the ends 134 of the base portions 112 fig5 through 9 show vertical cross sections consistent with either a rectangular or ring type manhole cover support these figures feature the inventive gussets as they occur in various flange and wale configurations suitable for use in the cover supports of the invention while the keeper wall 214 is depicted as extending substantially vertically from the base 212 it is to be understood that they could also be slightly frustroconical upwards therefrom as depicted in fig2 fig6 shows gussets 224 and 228 formed in a simple strait flange 216 bent substantially orthogonally from the keeper wall 214 fig6 and 7 show gussets formed in two different hollow wales 230 and 231 the wale depicted in fig7.