I have successfully configured Project Server Service Application on my SharePoint 2013 machine, I am using SharePoint 2013 SP1 and SQL Server 2014 Enterprise.

When I create a Project Server Web, Database provisioning fails and I get the following error in Event Log

    Failed to provision site PWA with error: Microsoft.Office.Project.Server.Administration.ProvisionException: Failed to provision database.
Database provisioning failed. The database WSS_Content_ProjectWebApp contains a non project schema and cannot be used. ---> Microsoft.Office.Project.Server.Administration.ProvisionException: Database provisioning failed. The database WSS_Content_ProjectWebApp contains a non project schema and cannot be used.
   at Microsoft.Office.Project.Server.Administration.PsiServiceApplication.EnsureProjectServiceDatabase(ProjectProvisionSettings provset, String collation, ProjectDatabaseStateType& originalDatabaseState)
   --- End of inner exception stack trace ---
   at Microsoft.Office.Project.Server.Administration.PsiServiceApplication.EnsureProjectServiceDatabase(ProjectProvisionSettings provset, String collation, ProjectDatabaseStateType& originalDatabaseState)
   at Microsoft.Office.Project.Server.Administration.PsiServiceApplication.CreateSite(ProjectProvisionSettings provset)