这个SP适用于各种语言的版本，下载地址：
http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=20310611&linkID=9240698
具体更新内容参考readme：
The following issues have been resolved in AutoCAD Civil 3D 2012 Service Pack 2:
Alignments
- Creating spiral curve using the Design Criteria: Tan-Tan with Curves no longer results in the application closing unexpectedly.
- Applying a Curve-Line-Curve transition to the end of a curve no longer results in the second curve doubling back on itself.
- An error is no longer generated when modifying a station equation with overlapping values.
API
- AddPointGroup to Surface on .NET no longer generates an error.
- Aeccxuilandloader and AeccSvrLoader no longer generate errors when hovering over some Civil 3D entities with rollover tooltips are enabled.
Catchments
- Creating a Catchment from Object with pickfirst turned on no longer causes the application to close unexpectedly.
Cogo
- The COGO Editor now reports the correct traverse length when using 2 distance unknowns.
- The COGO Editor now retains entries in the description field.
Corridor Design
- Using the Drive command on a Feature Line object no longer causes the application to close unexpectedly.
- An issue where a change to the Offset End Station resulted in an unusable drawing has been resolved.
- Switching between drawings while Station Tracker is enabled no longer causes the application to close unexpectedly.
Corridor Volumes
- Volume calculations using sample lines and section views provide more consistent results.
Cross Section Views
- Performance when using the Change Band Set selection tool in the Section View Group Properties dialog box has been improved.
- Opening a Civil 3D 2010 drawing containing the OverlayAndMill subassembly in Civil 3D 2012 no longer results in a display issue with the section views.
Cross Sections
- The right side of a Sample Line is now visible to the Intersection or Apparent Intersection Osnap commands.
- Referenced Cross Section Labels whose placement has been modified no longer revert back to original their location after reloading the XREF.
Data Exchange
- An imported Structure will now use the expected dimension rather than the dimension of the first Structure of the imported group.
Feature Lines
- Stability when grip editing a Feature Line has been improved.
- Creating Feature Lines from objects when the objects are overlapping closed polylines no longer causes the application to close unexpectedly.
General/Other
- The stability of the Audit command has been improved.
- A memory issue that prevented opening some drawings from previous releases has been resolved.
- An issue that caused an error when closing a drawing has been resolved.
- Renaming a layout while the Sheet Set Manager is open no longer displays an error message in the command line.
- The display of custom linetypes has been improved.
- Right-click menus from Prospector have been updated to resolve display issues.
Grading
- An error while using the Grade to Surface command has been resolved.
- Saving a drawing after running the Automatically raise/lower to balance the volumes command no longer causes the application to close unexpectedly.
Hydraflow Express and Hydraflow Storm Sewers
- The following issues related to Inlet calculations and reporting have been resolved:
- Inlet Calculations have been clarified to match HEC-22 requirements.
- Combination inlets in sag conditions now report expected depth and spread results.
- Slotted drains in sag condition no longer display the gutter spread and gutter depth values as bypass in reports.
- Slotted drains in sag condition now calculate expected depth and spread values while transitioning between weir and orifice flow.
- Open Area Design calculations are now less than or equal to the product of grate length and width.
- 3D images for Inlets without depression specified no longer depict a local depression.
- 3D images for Inlets with local depression now depict the correct grate slopes.
- Section images for on-grade inlets now depict the expected results for the entire spread.
- Inlet efficiency is now calculated as expected when the frontal flow width is less than the gutter width.
Hydraflow Storm Sewers
- Storm Sewer calculations have been clarified to follow methodologies according the HEC-22.
- Storm Sewers using HDS-5 inlet control option now report expected results.
- The following issues related to Inlet calculations and reporting have been resolved:
- Inlets with no tributary area now report expected flow capture results.
- Gutter depth and spread no longer calculate as negative values.
- Inlet Section Views now correctly show the grate slope when there is local depression.
- Inlet Section View display shows spread correctly in 2D when depression is ignored.
- A column in Interactive Designer is now labeled "Local Depression" to be consistent with the data-entry field.
Hydraflow Express
- Text in images exports clearly.
- Channel calculations for gutter channels now match the gutter calculations performed for Inlets.
- The following issues related to Inlet calculations and reporting have been resolved:
- Gutter depression values can now be set to zero.
- Manning roughness n-value default for gutter sections has been set to 0.016 for Inlet calculations.
- The following issues related to Culvert calculations and reporting have been resolved:
- Culvert calculations clarified to match HDS-5 requirements.
- The Manning roughness n-value list for Culverts now includes values up to 0.035 to match HDS-5.
- Circular culverts now report consistent tailwater results as expected across a flow range.
- Box culverts under outlet control now report expected headwater values.
- Horizontal elliptical pipes now report expected headwater values.
- Elliptical Culvert calculations now report expected headwater values above the crown of the pipe.
Hydraflow Hydrographs
- Resizing column widths no longer revert to original size.
- Correct dates are now printed in report data.
- Hydrograph plots are now displayed correctly on computers running Windows XP 32-bit.
Inquiry
- Switching between drawings with the Profile View inquiry, elevation & grade between two points command active no longer causes the application to close unexpectedly.
Intersection
- An issue with Offset Profiles that resulted in unexpected results when creating an intersection has been resolved.
Labels
- An issue where referenced Pipe Spanning labels list the incorrect distance after reopening a drawing has been resolved.
- Cogo Point labels in drawings from a previous release now retain rotation properties.
- An issue where referenced Pipe Network Labels in section view disappear after reopening a drawing has been resolved.
LandXML
- Importing a Pipe Network with structures deselected no longer causes the application to close unexpectedly.
Lines and Curves
- The Deflection-Distance transparent command now supports angles less the zero.
Parcels
- An error when creating a parcel using the Slide Line Create command has been resolved.
Pipe Networks
- Opening drawings with external references no longer causes the application to close unexpectedly.
- Selecting a pipe part while creating a Profile View no longer causes the application to close unexpectedly.
- Creating a Pipe Network while the Panorama is open with a deleted network no longer causes the application to close unexpectedly.
- Solid hatching now displays as expected on curved pipes.
- Solid hatching now displays as expected in Profile Views.
- Synchronizing a Pipe Network with a part swapped in the source drawing now changes updates the style as expected.
- Setting a template with custom optional Pipe Network parameters as the default template no longer returns an error message.
- Displaying large numbers of Pipe Network parts in Prospector is no longer causing slow performance issues.
- Issues recognizing the correct Manning roughness n-value for parts has been resolved.
- Issues setting and retaining a structure's On Grade / On Sag setting have been resolved.
- Pipe length data is now available in structure tables displaying connected pipes.
Plans Production
- An issue where superimposed profiles are not transferred to view frames in a referenced drawing has been resolved.
Points
- Moving a Point using Osnaps now changes the point elevation.
- Assigning user-defined properties to a Point Group from the summary tab no longer results in the application closing unexpectedly.
Profile View
- Dragging a Profile Label to the end of a Split Profile View using Osnap no longer results in the application closing unexpectedly.
Profiles
- Offset Profile geometry has been updated to provide better results when sampling and labeling.
Project Management
- Drawings with circular dependencies now generate a prompt when being checked in.
Quantity Takeoff
- A calculation error when using formulas has been corrected.
- Alignments can now be assigned as a pay item.
- The Pay Item and Pay Item Categorization files now default to the previously browsed path.
Shortcuts
- Performance when opening a drawing containing references has been improved.
Surface
- The Drape Image command no longer results in a reversed image when hardware acceleration is enabled.
- Creating a surface mask while in wireframe view style no longer results in the application closing unexpectedly.
- The accuracy when calculating surface volumes has been improved.
- An issue where adding a 3D polyline as a surface breakline causes the application closing unexpectedly has been resolved.
- Watershed analysis calculations are now launched when the Run Analysis button is selected.
Survey
- Transformation Settings no longer change when migrating a previous release drawing.
The following issues have been resolved in AutoCAD Civil 3D 2012 Service Pack 2.1:
General/Other
- Drawing stability when closing drawings containing data references has been improved.
- An issue where alignments do not plot according to the STB plot style has been resolved.
Hydraflow Storm Sewers
- An issue where running a default analysis with design mode in Hydraflow Storm Sewers causes the application to close unexpectedly has been resolved.
Hydraflow Hydrographs
- The Hydrograph Types tab now displays the full list of hydrographs.
Pipe Networks
- Referenced network section view labels for pipes and structures are no longer lost when exiting the application and reopening the drawing.
- Referenced pipe network styles retain changes as expected when the drawing is saved and re-open