Can on sloped ground with 1.00 m to 2.5 m in a distance 35 m bottom of# isolated and partly combined bottom with designed depth at difference levels?or should be one level by increasing depth at higher end,or averaging?

Question

Dear sir,
There is sloped ground with 1 to 1.2m difference in level .The designed foundation depth is 2.5 m .can I place bottom of isolated footing and partly combined fitting at different levels as per design depth,or they have to at one level by taking average GL or by consider depth  design  at lower level by increasing at higher end
Regards
K S Rao
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