The phrase "assured ground" is correct and usable in written English.
It can be used in contexts where you want to convey a sense of certainty or reliability regarding a particular situation or foundation.
Example: "With the new evidence presented, we now have assured ground to proceed with the investigation."
Alternatives: "solid foundation" or "secure basis".
Long Run's jumping is a little less assured and the ground may not be in his favour.
If they come under assault, Mr. Simon said, rest assured that the ground is being readied for "something much, much worse" against everyone else.
It may be a year or more before the Iraqis get power back into their own hands, after Washington has been assured that the ground is prepared for a stable pro-Western democracy strong enough to fend off any nefarious influences from the east.
Not that Gillard's position on the moral high ground is assured.
I rose from the ground and assured him that it was an oversight and if he redeposited the check everything would be O.K.
You owe this president no respect or allegiance, the white racists were thereby assured on such bogus grounds.
They may say that the Davidsonian account cannot assure sufficient common ground to resolve conflicts between moral frameworks (or to ensure that there is really only one framework), and that MacIntyre's approach is likely to work at best only in some cases.
On 9/14/01, Mr. Bush picked up a bullhorn at ground zero and assured rescue workers: "The people who knocked down these buildings are going to hear from all of us".
The West Virginians in "Given Ground," Ann Pancake's assured first collection of stories, set fire to their homes for insurance money, die disproportionately in car crashes and wars and succumb to middle age in their 20's -- and all without much emotional fuss.
The performance is assured by tests on the ground and is confirmed by in-flight observations after the launch (Satoh et al. 2015).
