Removing Sidewalk

Planning to remove my front sidewalk (the portion leading from the house to the public sidewalk). The sidewalk is at grade level up near the house. However, it descends down to approximately 8 inches below grade where it meets the public sidewalk (~25 feet out). There is a small retaining wall on either side that gradually increases in height from the house outwards.

My plan is to remove the sidewalk and retaining walls and fill in the area with soil. Then lay down patio stones or slate stepping stones with grass growing in between each stone. Essentially, I'll be elevating the walking path so the front lawn is completing flat from one side to the other.

The initial plan was to use a jackhammer to break up the whole sidewalk, then use the pieces elsewhere or unload them. However, it was recommended to me to only break up the portion of the sidewalk that is higher up in elevation. It was suggested that I simply fill in over the deeper portion of the sidewalk, then install the stones, lawn, etc. over this. I'm concerned that this may not be very sound, particularly in periods of heavy rain. Being in NJ, we do get a decent amount of rain in the Spring and Fall. Am I overthinking this? Will the grass and soil remaing in place or wash out?

I would be happy to clarify if the above explanation is unclear.
Thanks

You will want to compact the fill under the new walk or not. But getting equal compaction for the whole length of the walk may be a problem.

without seeing what you have there other then a description it is hard to answer your question about possible erosion. You should have base for your walkway and the base relates to your flagging material. Rememeber over time that any flagging you lay on soil will shift and move to some extent do to frost. On all my projects i install a base below frost so i can gaurantee my work. This would be a crush stone base if using conventional stone flagging.A picture of the area would be helpful but i am recommending that you take up the whole area and not leave any existing flagging as there should be a prepared base for the whole area.

As recommended, attached is a photo of the section of the of the sidewalk mentioned in the original post.

Thanks

That is exactly what they did to fill in a pool I once had. They busted up all the concrete around it and the stairs as well. Then they fill the pool in with all the concrete. Fill sand in over that, then fill dirt, soil, and grass. Turned out nice.

If you're going to leave the existing sidewalk in place, I'd suggest at least breaking it up (so cracks will allow moisture to drain through instead of ponding and saturating the base under your finished surface). Wouldn't hurt to used a granular backfill material either (3/4 minus), on top of the sidewalk.

Will you be building a step at the front sidewalk line, to compensate for the difference in elevation?

Yes. I'm going to replace the existing retaining wall out front with a stone wall. The step will be part of the wall.

One question, what doest 3/4 minus refer to?

It's a reference to the rock size of the gravel mix you'll use as a base--all of the material will pass through a 3/4" sieve opening, with nothing retained. The larger the number, the larger the maximum rock size in the mix.