I don't work with abaqus. but I read this article before.I hope it helps you

u can define absorbing boundary by simple methods rather than going for lysmer boundary...by using infinite elements i faced lot of problems...we can model the soil such that the damping is frequently increasing...so that it ll simulate the absorbing boundary

Hello

Are you solving a same problem by implicit an explicit?

what is the value of time in your problem?

according to the problem, you must use implicit or explicit solution and it can be different between implicit and explicit results.

Will the dashpots works in implicit or explicit problems??