Dirts to soft guys!

Good day fellow carpenters, I'm currently lifting this one story 1929 house in a heavy rain area where the exterior rim girder has completely dry rotted and buckled as shown above along the last picture being the next girder over having twisted because of the exterior rim girders buckling. The house has settled 2½" from my 0 datum point. I have about 10, 13 ton jacks down there under a temporary beam along with 2, 20 ton jacks. I have successfully braced the weight and since cut out the bad exterior girder which was 3 2x6 nailed together. I am adding three new 2x6x16' PT boards there with staggered joints. My problem is that the ground under my jack is to soft and when I try to jack up the house to level the jacks just sink. I have dug roughly 6" deep holes under the jacks and filled them in with compaction gravel along with putting 4"x6"x 2' blocking under the jacks to give it a wider surface area and even with all that the jacks are just sinking right into the ground. I keep decompressing the jacks and adding more compaction gravel under the blocking and it's still just sinking 🙃. So I am asking for ideas and solutions fellow carpenters.