We have a 4" ABS pipe used for storm-water drainage. While using a trencher, we accidentally hit the pipe and caused a crack that covers about 1/4 of the pipe circumference. The crack is close to a Wye adapter (about 1/2 inch distance to the Wye adapter).

The pipe is under a path where couple of times a year some small cars can drive over. It is about 1 foot deep.

I could fix the leak using some asphalt sealant or ABS cement and a piece of pipe to cover the cracked area, but that would not recover the pipe strength. When we drive over it, I am afraid it can collapse or crack even more.

What is the proper way to fix it? I would rather not cut out the whole piece including the Wye adapter. This is because Wye is connected to an elbow and it is connected to another adapter... I am OK with cutting the pipe after the Wye. Any recommendations?