"solid marriage" is correct and usable in written English.
You can use it to refer to a marriage that is strong or well-established. For example, "They have a solid marriage that has lasted for years."
And yet it was a long, solid marriage.
Nonetheless, the pedophilia scandal has undermined what had once been a solid marriage of convenience.
A solid marriage is linked to happiness, as is participation in social networks.
Sergeant Bales's lawyers contend that he had a solid marriage and no drinking problems.
She also gave her all to what she thought was a solid marriage.
It was the sort of fight that means nothing in a solid marriage and everything in a shaky one.
Even those in solid marriages have trouble handling routine conflict.
If you're looking for solid marriages, head to Massachusetts, not Alabama.
For 26 years, French and Henry seemed to be one of the most solid marriages in showbusiness, but they divorced amid tabloid allegations of his infidelity.
His friends could have served as an advertisement for Scientology — they were wealthy high achievers with solid marriages, who embraced the idea that the church had given them a sense of well-being and the skills to excel.
Over time, my reporting on poverty has led me to disagree: Solid marriages have a huge beneficial impact on the lives of the poor (more so than in the lives of the middle class, who have more cushion when things go wrong).
