Yes, you can find previous years' papers for the Civil Engineering optional subject in the form of online question banks.

There are several online platforms where you can access previous years' question papers for the Civil Engineering optional subject. One such platform is EduRev, which provides a wide range of study materials and resources for various competitive exams, including the UPSC Civil Services Examination.

Here is how you can find previous years' papers for Civil Engineering on EduRev:

1. Visit the EduRev website: Go to the EduRev website by typing "www.edurev.in" in your web browser's address bar.

2. Search for Civil Engineering optional subject: In the search bar on the homepage, type "Civil Engineering" and press Enter. This will take you to the Civil Engineering page on EduRev.

3. Navigate to the question bank section: On the Civil Engineering page, look for the "Question Bank" section. Click on it to access the question bank for Civil Engineering.

4. Select the appropriate filters: In the question bank section, you will find various filters to narrow down your search for previous years' papers. You can filter the papers by year, exam, difficulty level, etc. Select the appropriate filters based on your requirements.

5. Browse and download previous years' papers: Once you have applied the filters, you will see a list of previous years' question papers for the Civil Engineering optional subject. Browse through the list and click on the papers you want to download. The papers are usually available in PDF format.

6. Additional resources: Apart from previous years' papers, EduRev also provides solutions, explanations, and other study materials related to Civil Engineering. You can explore these resources to enhance your preparation for the Civil Services Examination.

Conclusion:
In conclusion, you can find previous years' papers for the Civil Engineering optional subject in the form of online question banks. Platforms like EduRev offer a convenient way to access and download these papers. By utilizing these resources, you can familiarize yourself with the exam pattern, gain insights into the types of questions asked, and improve your overall preparation for the UPSC Civil Services Examination.