The surveyor's tunnel section library imported dxf drawings at the wrong angle.

When surveyors import dxf drawings from tunnel section library, there may be many reasons for incorrect angles. The following are possible causes and solutions:

1. coordinate system mismatch: The imported dxf diagram may use different coordinate systems, resulting in incorrect angles. Before importing dxf drawings, you can try to convert the coordinate system of dxf drawings into the same coordinate system as the tunnel section library.

2. Scaling problem: The imported dxf diagram may be scaled during the import process, resulting in incorrect angles. When importing dxf drawings, you can check whether the zoom option is set correctly and try to adjust the zoom option to get the correct angle.

3. Unit problem: The imported dxf diagram may use different unit systems, resulting in incorrect angles. Before importing dxf drawings, you can convert the units of dxf drawings into the same units as the tunnel cross-section library.

4. Error problem: The imported dxf diagram may have measurement errors or data loss, resulting in inaccurate angles. Before importing dxf chart, you can check the measurement accuracy of the original dxf chart to avoid data loss as much as possible.

If the above methods can't solve the problem, it may be necessary to further investigate the specific specifications and requirements of dxf diagram and tunnel section library. You can also consider consulting professional surveyors or software technical support personnel to get more specific solutions.