Your Civil 3D is crashing randomly at different times during different commands.
We need to check there the Graphics driver that is on your workstation. An incorrect Graphics driver is the leading cause of random crashing in Autocad Products.
Use one of the recommended or certified drivers that Autodesk have tested from here
(this will not usually be the latest driver for your card but do use the Autodesk tested and approved driver, not the latest):
Set the first dropdown to Autocad (for Civil3D as well), then set dropdown 2 to your Civil 3D version year, then your operating system, and Graphics Card manufacturer. Then see the list to see all the tested cards they have done. Once you have found the driver that works best for your graphics card, you will be able to download it from the icon on the right. (this will not usually be the latest driver but it will be the one that works BEST)
(If you can not find your graphics card in the list go back year by year to see if it was certified for a previous version, then use that driver. Gaming graphics cards have generally not been tested, only workstation cards)
See if this resolves the crashing issues once you have had time to test this out.