You don't say what state you're from and every state has different workers comp. laws. That means that every state has different ways to settle a case. Depending on how you settle your claim, social security may require that you establish a medi-care set aside trust if you are on social security disability. If you are on social security supplemental income, it may also take off-sets for what you receive from workers' comp. So the answer is yes, your workers' comp settlement may affect your social security. It would be best to consult an attorney who does both workers' comp. and social security law.
The offset can possibly be minimized with special language in your workers comp settlement agreement. You should ask a local work comp lawyer for details.
You used the term SSI which is a monthly payment that is conditional on the resources you own, such as a bank account. For single people, your SSI check quite possibly will be affected adversely if you have cash or investments that are in excess of $2,000.00. You are supposed to report any workers compensation settlements to social security.
If you've already settled your workers' comp. settlement, then you're asking this question too late. You should have considered this BEFORE you settled. The answer is probably "Yes." SSI is for very low income individuals. Once you get your settlement, you may not be very low income anymore. It will depend on the terms of your settlement. If you had an attorney for your workers' comp. case, you should go back to that attorney and ask your question. There may still be some things the attorney can do to help out on this.