There are trade-offs in every design. The 1911 and Glock are both VERY durable, but like any machine, may break. When they do break, you can get replacement parts for either of the two designs very readily from the manufacturer or aftermarket. And both designs can be adapted to meet your needs if you find them lacking.
A lot of folks are recommending the Ruger revolvers. Keep in mind that while there is A LOT of steel in these guns, that steel can still be brittle and crack. The Ruger revolvers are made out of stainless castings, and while rare, there can be voids or irregularities that could cause structural damage at some point. Ruger has an outstanding reputation with their customer care, and will usually always repair or replace whatever you send them provide you were not obviously abusing or misusing the gun. But the key point here is that Ruger will do the work, not you. You will not be able to get, fit, or install most internal parts for it. Also, Double Action revolvers are typically very reliable....Until they lose timing or you drop them on an open cylinder......They are not impervious to breaking.
On this note there are also some very robust designs out there such as the HK USP, Sig Sauer P2XX series, S&W 3rd Gen Semi Autos, etc, etc, but they too may require factory service for certain types of internal repairs. That being said, good luck breaking them. You'll need a mountain of ammo and complete ignorance of maintenance schedules.
In Short:
1911 & Glock will give very good durability but will offer you the ability to do virtually all maintenance and repairs. The Glock obviously being much easier to work on than the 1911.
Revolvers are good and strong, but are not the end-all of durability. They have their weak spots, and if they go down, they go down hard with little a home or hobby metal shop can do to fix them.
Other good robust guns are Hk USP, Sig Sauer P220, 226, 228, 229 M11A1. S&W 4006, 4013, 4053, 4506, 4566, 4516, 4513, 457, 910, 915, 3913, 3914, 3953, 6906, 5906, etc, etc, etc. It is rare that these break and can be bought lightly used for a very fair price.