They can both translate as "to lean" but I think they're not interchangeable. Or are they? Take this sentence for example:
Can I use 偏る in this sentence?
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If you describe physical inclination with those two words, it's like this:
Though English "lean" covers both, 偏る tells that something becomes uneven as if its center of gravity is drawing near to one side, while 傾く means that something loses its uprightness in a way getting unstable.
The ship gave a lurch and the cargo of coal leaned to one side.
For your example:
it cannot be replaced with 偏る in the usual sense, unless, say, what you have thought is wall is actually a sandbag-like structure and its packed content flows to either side due to the earthquake.