⚠ May require more grout than anticipated: Difference between revisions
From ASDSO Dam Safety Toolbox
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[[Category:Rehab vs. Replacement Outlet Works]] | |||
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''' ''Message: Sliplining perforated CMP can be problematic because grout may fill holes in embankment.'' ''' | |||
'''Lessons Learned:''' | '''Lessons Learned:''' | ||
#If pipe has holes, consider replacement instead of slip lining. It can be difficult to estimate grout needs because voids adjacent to the conduit can fill with grout. | #If pipe has holes, consider [[replacement]] instead of slip [[lining]]. It can be difficult to estimate grout needs because voids adjacent to the conduit can fill with grout. | ||
#Grout mix and placement technique is very important. The grout must be flowable in order to properly seal the annular space. | #Grout mix and placement technique is very important. The grout must be flowable in order to properly seal the annular space. | ||
#Grout is especially important with mechanical joints – more important than with a fusion welded joint. | #Grout is especially important with mechanical joints – more important than with a fusion welded joint. | ||
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<gallery mode="slideshow"> | <gallery mode="slideshow"> | ||
File:SMR1.jpg|This central Montana dam had holes in the invert of the pipe. The pipe was sliplined with a mechanically joined HDPE pipe. | File:SMR1.jpg|This central [[Montana]] dam had holes in the invert of the pipe. The pipe was sliplined with a mechanically joined HDPE pipe. | ||
File:SMR2.jpg|This central Montana dam had holes in the invert of the pipe. The pipe was sliplined with a mechanically joined HDPE pipe.The grout take was significantly higher than the original quantity estimate – voids around the pipe were far worse than anticipated. | File:SMR2.jpg|This central Montana dam had holes in the invert of the pipe. The pipe was sliplined with a mechanically joined HDPE pipe.The grout take was significantly higher than the original quantity estimate – voids around the pipe were far worse than anticipated. | ||
File:SMR3.jpg|This central Montana dam had holes in the invert of the pipe. The pipe was sliplined with a mechanically joined HDPE pipe.The grout take was significantly higher than the original quantity estimate – voids around the pipe were far worse than anticipated.It was difficult to get a good seal of annular space and to achieve the correct grout mix (due to winter conditions) – sand caused bridging in the annular space. | File:SMR3.jpg|This central Montana dam had holes in the invert of the pipe. The pipe was sliplined with a mechanically joined HDPE pipe.The grout take was significantly higher than the original quantity estimate – voids around the pipe were far worse than anticipated.It was difficult to get a good seal of annular space and to achieve the correct grout mix (due to winter conditions) – sand caused bridging in the annular space. |
Latest revision as of 00:28, 2 December 2022
Message: Sliplining perforated CMP can be problematic because grout may fill holes in embankment.
Lessons Learned:
- If pipe has holes, consider replacement instead of slip lining. It can be difficult to estimate grout needs because voids adjacent to the conduit can fill with grout.
- Grout mix and placement technique is very important. The grout must be flowable in order to properly seal the annular space.
- Grout is especially important with mechanical joints – more important than with a fusion welded joint.
- Low head dams might be more cost effective to replace than slipline.
Note: The content on this page was originally created as part of DamOutletWorks.org (DOWL, 2018). It has subsequently been updated and reformatted as part of the Dam Safety Toolbox.
Revision ID: 4702
Revision Date: 12/02/2022