| Page Type |
Page
|
| Main |
Existing Conditions
|
| Topic |
Pipe Deterioration
|
| Subtopic |
Deterioration Accelerates with Time
|
| Subtopic |
Extent of Corrosion May Limit Repair Options
|
| Subtopic |
Deterioration at Invert is Hard to Detect
|
| Subtopic |
Corrosion Occurs from Outside In
|
| Subtopic |
Inspect Full Length of Pipe
|
| Subtopic |
Connection between Riser and Conduit often First to Fail
|
| Subtopic |
Bituminous Coating Impact on Design Life of Pipe
|
| Subtopic |
Treatment Types
|
| Subtopic |
Exposed Steel
|
| Subtopic |
Longitudinal Cracking
|
| Subtopic |
Joint Deterioration - Pay me now or pay me later
|
| Subtopic |
Service Life
|
| Subtopic |
Continuous Flows can Reduce Deterioration in Downstream Valves
|
| Topic |
Seepage and Piping
|
| Subtopic |
Seepage and erosion around the conduit must be taken seriously
|
| Subtopic |
Seepage into pipe can go unnoticed for years until sinkhole develops
|
| Subtopic |
Deteriorated conduits with holes can cause seepage
|
| Subtopic |
Multiple Factors May Contribute to Internal Erosion Failures
|
| Topic |
Operation
|
| Subtopic |
Debris Clogging Intake Structure can lead to Overtopping
|
| Subtopic |
Use a Limit Nut on Gates
|
| Topic |
Erosion/Energy Dissipation
|
| Subtopic |
Headcuts in stream can lead to failure
|
| Subtopic |
Erosion that cuts into the toe of dam can cause embankment instability
|
| Topic |
Investigation Methods
|
| Subtopic |
Go-Pro Mounted on a Sled
|
| Subtopic |
Closed Conduit Television Camera
|
| Main |
Rehab vs. Replacement
|
| Subtopic |
⚠ Gather Information Before Design
|
| Subtopic |
Pipe too deteriorated? Sliplining is not an option.
|
| Topic |
Conduit / Pipe Rehabilitation
|
| Subtopic |
Slipline Example 1
|
| Subtopic |
Slipline Example 2
|
| Subtopic |
⚠ May force water along outside of pipe
|
| Subtopic |
⚠ May require more grout than anticipated
|
| Subtopic |
CIPP Works well for Smaller Conduits
|
| Subtopic |
⚠ Cautions for CIPP in Large Diameter Conduit
|
| Subtopic |
CIPP Example 1
|
| Subtopic |
CIPP Example 2
|
| Subtopic |
Internal Repair of Isolated Damage (Joint)
|
| Subtopic |
Filter Diaphragm Exhibits
|
| Subtopic |
Filter Diaphragm may Require Downstream Pipe Replacement or Extension
|
| Topic |
Replacement
|
| Subtopic |
Coated CMP Example, Low-Hazard Dam
|
| Subtopic |
HDPE Encased in Concrete
|
| Subtopic |
PVC in Small, Low-Hazard Dam
|
| Subtopic |
Concrete Bedding is Easier to Bed than Clay
|
| Subtopic |
Importance of a Dry Trench During Construction with Concrete Cradle
|
| Topic |
Abandonment
|
| Subtopic |
Abandonment Example 1
|
| Main |
Outlet Configuration
|
| Topic |
Upstream Control
|
| Subtopic |
Sloping Gate Example 1
|
| Subtopic |
Sloping Gate Example 2
|
| Subtopic |
Upstream Gate Stem can be Protected by Concrete or Riprap
|
| Subtopic |
Upstream Control with Single Gate
|
| Subtopic |
Upstream Control with Multiple Gates
|
| Subtopic |
Ice and Debris may cause Damage
|
| Subtopic |
Wet Tower with Spillway Splitter Wall No. 1
|
| Subtopic |
Wet Tower with Spillway Splitter Wall No. 2
|
| Subtopic |
Dual Chamber with Dual Slide Gates
|
| Subtopic |
Single Chamber and Gate
|
| Topic |
Downstream Control
|
| Subtopic |
⚠ Include an Upstream Gate/Valve
|
| Topic |
Siphon
|
| Subtopic |
Siphons when regular releases aren't needed
|
| Subtopic |
Siphoning May Not Always Be Possible
|
| Subtopic |
Low Pressure During Siphoning Can Collapse Pipe
|
| Subtopic |
Pump... or Siphon?
|
| Subtopic |
Siphons can pose Reservoir Level Control Challenges.
|
| Main |
Filters and Drains
|
| Topic |
General Information
|
| Subtopic |
Filter Diaphragm Exhibits
|
| Subtopic |
Filter Diaphragm may Require Downstream Pipe Replacement or Extension
|
| Topic |
Drainage Pipes
|
| Subtopic |
Access is Needed for Inspection, Cleanout, and Measurement
|
| Subtopic |
Typical Toe Drain Pipe Construction
|
| Topic |
Soils
|
| Subtopic |
Typical Filter and Drain Configurations
|
| Main |
Accounting for Energy Dissipation
|
| Subtopic |
Hydraulic Jump Stilling Basin Examples
|
| Subtopic |
Impact Basin Examples
|
| Subtopic |
Stilling Well Examples
|
| Subtopic |
Conduit Outlet Expansion Examples
|
| Subtopic |
Riprap and Concrete Blocks Examples
|
| Subtopic |
Baffled Drop Examples
|
| Main |
Construction Considerations
|
| Subtopic |
Filter Diaphragms
|
| Topic |
Pipe Installation
|
| Subtopic |
Concrete Bedding Easier than Clay
|
| Subtopic |
Importance of a Dry Trench During Construction with Concrete Cradle
|
| Subtopic |
Pipe Grade
|
| Topic |
Dealing with Mud/Muck
|
| Subtopic |
Anticipate dewatering problems in advance
|
| Subtopic |
Underwater Construction
|
