Adding z values from points to line

[SBreckan]

I have two lines (the center line of a tunnel) that lack z values, they are currently just flat lines with start and end xy values. I do have the z values in points - but how do I get the values from the points to the lines? I have the basic license and cannot use the Split Line at Point tool.

I would like the lines to be split at each point and assigned a z value. I have two lines and approximately 400 points, the elevation of the tunnel differs between a few meters below sea level and 90 meters above.

I am using arcmap for desktop 10.3.1

Thanks in advance.

[DeanMcGowan]

Do you have 3D analyst? If so create a small buffer around each point (less than the minimum distance between nodes) and then create the TIN from the buffered layer.

You should now have a tin that covers the nodes on your line. Now use the "Interpolate Shape" tool to create a 3D version of your line. The "Interpolate Vertices Only" option should be checked.