concrete interlocking pavers installation

Hi! I am installing some interlocking pavers on the front of my house to replace a very poor job that was made 10 years ago. A section of the walkway (about 42 inches long) will have to come next to the porch, which is a 10" thick concrete slab that was poured at the same time as the foundation of the house, and it supports the porch roof via three concrete columns (three concrete pillars, 48" deep support the slab). There is a 24" void under this slab to prevent frost from pushing it upwards. If I butt my pavers to the porch, the gravel will sink under the porch and so will the pavers. Because I can't fill this void, I thought I could bolt some angle irons to the bottom of the slab, and then bolt a board of pressure treated lumber to that angle-iron, but I am afraid that this 42" long, 2" thick board might be enough to push the slab upwards if there comes a severe winter. I also thought of installing a floating plate of steel, 24" deep flush with the edge of the porch slab, so it the freeze pushes it upwards, it will only stand proud of the walkway. Would you have a better advice, or am I on the right way? Thanks.