rehabilitation alternatives - mi-wea.org technologies scholl.pdf · •the liners are resistant to...

Rehabilitation Alternatives

MWEA Collection System Seminar

October 1, 2009

Overview

• Types of Rehabilitation

• Trenchless Categories

• On-Line Replacement

• In-Situ Options

• Selecting the Best Solution

Types of Rehabilitation

• Excavation and Replacement

• Trenchless Technologies

Reference:

New Pipes for Old: A Study of Recent Advances in Sewer Pipe Materials and Technology, Project 97-CTS-3, Water Environment Research Foundation, 2000

Trenchless Categories

• On-line Replacement

• In-Situ Renovation

Options for On-Line Replacement

Method DiameterRange, inches

Installation Length, feet

Old Pipe Material

Application

Pipe Bursting-Pneumatic

2 - 24 475 Ductile Iron, VCP, Concrete

Gravity and Pressure lines

Hydraulic 2 - 24 475 Ductile Iron, VCP, Concrete

Gravity and Pressure lines

Static Pull 4 - 24 650 Concrete, VCP Gravity sewers

Extraction 4 - 14 250 Ductile Iron, Steel

Pressure lines

Cutters & Expanders

1 - 6 300 Steel, PE, PVC Pressure lines

Pipe Bursting / In-Line Expansion

• Description: outwardly displacing the existing pipe to make room for a slip lined pipe. Normally used with short sections. Allows for larger diameter pipes than existing pipes

• Options: static (no moving internal parts) or dynamic (provide pneumatic or hydraulic forces at point of impact) expansion heads

Static

Dynamic

In-Situ Options

• Slip-Lining

• Close-Fit Lining (CIPP)

• Coatings - Structural

• Point Repairs

Slip Lining• Description: Slide a flexible pipe of

a slightly smaller diameter into the existing pipe – the space between new and old pipe is grouted (foam, pea gravel, etc.) continuously prevent leaks and improve structural integrity

• Restrictions/ requirements: Can use with pipes that have structural problems. Requires ground surface access to lower the discrete pipe sections – large access pit. Doesn’t require elimination of normal flows

• Options: continuous segmental and spiral wound: HDPE (high density polyethylene), PP (polypropylene), PET-R (fiberglass reinforced polyesters), TR-R (reinforced thermosetting resins), and PVC (polyvinyl chloride). Some use small sections of stainless steel sleeves

Segmental

Spiral Wound

Continuous

Advantages of Sliplining

• It can be applied to most types of sewer pipe

• It is rapid and causes little disturbance to other buried utilities

• Depending on flows, installations can be done in live lines without bypass pumping

• It is most successful when there are long runs with few connections

• An improved interior surface with a reduced friction coefficient helps to improve flow

Considerations of Sliplining

• The reduced pipe diameter will cause loss of cross-sectional capacity

• When short pipe sections are used, the benefits of sliplining have to be offset against the increased cost of the jointing techniques

• Where connections are being made, the relative movements of the original pipe and the sliplined pipe need to be considered

• Poorly controlled grouting to the annular space can lead to buckling of the liner pipe

Types of Close-Fit Lining Systems


Max Installation Length, feet

Liner Material Application

Spirally Wound 4 - 100 300 PVC Gravitypipelines

Diameter Reduction

4 - 24 300 PE, PP Gravity and Pressure pipelines

Fold and FormLiners

4 - 64 300 PE, PVC Gravity (PVC) and Pressure (PE) pipelines

CIPP (inverted) 4 - 100 3,000 Resin-saturated fabric tube

Gravity and Pressure pipelines

CIPP (winched) 4 - 54 500 Resin-saturatedfabric tube


Fold and Formed / Rolldown• Description: fold and formed is when

flexible pipe in a U shape is inserted into host pipe. Rounding mandrels round out the pipe. Then liner is heated and pressurized to conform to original pipe shape. Swagelined and rolldown use chemical and mechanical forms respectively to temporarily compressed the lining before being drawn into the pipe.

• Restrictions and requirements: heat and pressure are used to create a snug fit between lining and pipe. Requires carful cleaning of the pipe. Also should give time for stabilizing because of high coefficient of expansion of material

• Options: PVC, PE, HDPE, high tensile polyester reinforced polyethylene

Advantages of Fold and Form Liners

• Disruption and risk of damage to other buried utilities is minimized

• Severely corroded pipelines can be lined• The liners are resistant to attack from most acids• Despite a slight loss of cross-sectional area, the

smooth interior surface of the liner may improve flow capacity

• Dimples in the lining indicate connections, which can be opened by robotic cutters

• No grouting is required

Considerations for Fold and Form Liners

• Reversion may sometimes not be completed fully

• Stresses may be locked into the liner, which over time can cause the liner to move in relation to the pipe

• The long-term performance of these liners is not fully researched

Cured In Place Pipe - CIPP• Description: a flexible liner such as

felt that is impregnated with thermosetting resins is inserted through the manholes into the pipe and then the resin is set ( hardens) through contact with steam or hot water. Inserted by winch in place and invert in place methods.

• Restrictions and requirements: no additional excavation is required, can be used on non-circular pipes, bends, offsets, and misaligned joints. Useful in pipes needing minor structural reinforcement. A Jointless solution. Has a curing time. Sometimes require flow bypass – lots of methods.

• Options: Resins – unsaturated polyester (poly-urethane), vinyl ester, fiberglass epoxy ; Textiles –polyester fiber felt

Advantages of CIPP

• Installation is relatively fast and excavation is not normally required

• Access is gained through existing manholes• The method is versatile and can be tailored to line

noncircular sections• It can negotiate bends and bridge offsets and missing

sections of pipe• CIPP can be used for full structural renovation or for thin,

hydraulic liners• Laterals can be reinstated in non-man-entry lines with

robotic cutters• Despite a slight loss of diameter, the smooth interior

surface may improve flow capacity

Considerations of CIPP

• The old pipe needs extensive surveying, cleaning, and preparation

• Bypass pumping is required• Pre-grouting may be necessary in damaged areas or

where there are voids• The liner pipe is flexible and needs support from

surrounding material• Over and under-cuts at lateral restoration can occur• As diameters get larger, costs tend to rise more rapidly

because of the weight and cost of material plus the greater difficulty of installation

Types of Coating




Spray-onLinings (Structural)

36 - 180 Various Reinforced cement mortar


Spray-onLinings (Non-Structural)

3 - 180 500 Epoxies, cement mortar


Coating• Description: material is applied

by spray, trowel, or roller to the host pipe and can be used as a patch or complete rehabilitation

• Restrictions and requirements: requires a clean dry surface, no loose material in sewer, cure in around 1 hour

• Options: epoxy, shotcrete, polyester, silicone, urethane, and vinylester.

Spectra Shield

Sewpercoat

Advantage of Ferro-cement

• It can easily accommodate noncircular sections and diameter changes

• Connections are easily incorporated into the relining

• It can be used in partial flows and precast invert sections can be incorporated

• The cross-sectional capacity loss is relatively small• It is possible to design for pressure line

rehabilitation• Work can be undertaken from existing manholes

Considerations of Ferro-cement

• Skilled and experienced operators are needed to achieve the required level of quality

• The system is not well understood as a rehabilitation technique

• Spraying is difficult to control

• Preliminary sealing may be necessary to avoid infiltration

Techniques for Point Repair




Robotic Repairs 8 – 30 N/A Epoxy resins,cement mortars

Gravity pipelines

Grouting N/A N/A Chemical Grouting


Link-Sleeve 4 – 24 N/A Special sleeves Gravity and Pressure pipelines

Point CIPP 4 – 24 50 Resin-saturated fabric tube

Gravitypipelines

Point Repair Practices for Collection Systems

Technologies Structural Integrity

CorrosionResistance

Advantages Disadvantages

Grouting Low Good •May improve hydraulic characteristics•Protects against corrosion•Provides soil stabilization around pipe

•Adds no structural capacity to pipe•Equipment intensive operation•Bypass pumping or system shutdown may be required

CIPP High Good •Able to provide area repair of numerous cracks

•Bypass pumping or system shutdown may be required•More expensive for small sections

Grouting –MechanicalSleeves

High Good •Good application for repairing joint leaks•Bypass pumping or system shutdown not required

•Only possible to repair a local area, such as a joint or single large crack

Universal Need for RehabilitationGuatemala

Chicago

Liverpool

Tucson, Arizona

Tucson Arizona

Unit Costs for Pipeline Rehabilitation using CIP Technology (Costs Corrected to ENR CCI 8574)

Bidders

Lo

cati

on

Yea

r 6"

CIP

($/LF)

8"

CIP

($/LF)

10"

CIP

($/LF)

12"

CIP

($/LF)

15"

CIP

($/LF)

18"

CIP

($/LF)

Source

Engineer's Estimate

San

Fra

nci

sco

,

CA

12

/06

$65.22 $86.96 $97.83 $119.57 NA NA

1

K.J. Woods Construction, Inc. $32.61 $32.61 $32.61 $43.48 NA NA

Ranger Pipelines, Incorporated $28.26 $27.17 $28.26 $39.13 NA NA

JMB Construction, Inc. $36.41 $35.00 $36.41 $50.44 NA NA

Engineer's Estimate

Vir

gin

ia B

each

,

VA

01

/06

NA $33.58 $67.16 NA NA NA

2

Suburban Grading and Utilities NA $33.23 $99.34 NA NA NA

Peters and White Construction NA $36.94 $38.06 NA NA NA

Tri-State Utilities NA $29.10 $83.95 NA NA NA

W.R. Hall NA $27.98 $87.87 NA NA NA

Engineer's Estimate C

olu

mb

us,

OH

01

/06

NA $41.64 NA $55.52 NA NA

3

United Survey, Inc NA $26.86 NA $39.18 NA NA

Reynolds Inliner, LLC NA $32.46 NA $35.82 NA NA

Insituform Technologies, Inc NA $27.98 NA $41.41 NA NA

Kokosing Construction Co. Inc. NA $29.66 NA $41.41 NA NA

American Water Survey NA $36.38 NA $58.20 NA NA

Kokosing Construction Co. Inc.

Hu

dso

n,

OH

03

/09

NA $21.10 NA NA $40.19 NA

4 United Survey, Inc NA $27.13 NA NA $65.30 NA

Insituform Technologies, Inc NA $23.11 NA NA $62.29 NA

Reynolds Inliner, LLC NA $26.12 NA NA $56.26 NA

Engineer's Estimate

Mo

un

t

Ver

no

n,

WA

05

/09

$28.00 $30.00 NA $34.00 NA NA

5 Columbia Pumping and Construction $31.60 $27.50 NA $49.60 NA NA

Insituform Technologies, Inc $30.00 $27.00 NA $31.00 NA NA

Michel's Corporation $37.00 $29.00 NA $38.00 NA NA

Cement Mortar Pipe / Grouting• Description: application of a cement

mortar to the inside of pipe line to protect them from corrosion or slip line cement pipe into sewer. Cement mortar coatings can be applied to concrete, steel, or iron pipes, and can extend the service life of a pipe by up to 50 years. The coating is made of one part sulfate resistant cement to two parts sand. The coating is applied by hand or by an automated spreading machine.

• Options: glass reinforced cement, polymer mortar, HOBAS pipe – glass reinforced polymer mortar (CCFRPM)

• Restrictions: Cement mortar cannot be applied in pipe networks with many bends, or in very cold regions.

In-Situ Liners / Modified Cross Sectional Liners

• Description: A soft liner is impregnated with a glass reinforced polyester laminate; this is pulled through the damaged drain run and molded rigidly in place by water or air pressure.

• Restrictions and requirements: pipe must be relatively clean – to create tight seal. Existing leaks must be properly repaired. Only acceptable in pipes larger than 48 inches

• Options: preformed strips (PVC) -strips and grout constitute their own structural system, geo-membrane sheets (HPDE) require access pits they are attached with anchor bolts to sewer, geo-membrane panels (HPDE) require anchor studs and space is filled with cementous grout

Example Unit Costs

Sewer Rehabilitation using Cured-In-Place (CIP) Technology

(Unit Costs Corrected to ENR CCI 8574)

Date CIP Products

Cost Range

Assuming a 50-foot lateral with

moderate root intrusion Source

2006

INFlex Liner™ $16.59 - $55.31

Methods for Cost

Effective

Rehabilitation in

Private Lateral Sewers:

Final Report. 2006.

Water Environment

Research Foundation.

Formadrain® $77.43 - $138.27

Inserv™ $66.37 - $70.8

MaxLiner™ $77.43 - $110.62

PermaLateral™ $82.96 - $165.93

Primeliner™ $16.59 - $77.43

Verline Lateral $44.24 - $82.96

TOP HAT® $17.7 - $26.55

PrimeLiner LC™ $11.06 - $22.12

Insituform® Lateral $33.19 - $88.49

LMK T-Liner $77.43

Fold and Formed Cont’d

CIPP Cont’d

Grouting sleeve – a type of CIPP

• Description: the pipe at a reduced diameter is sent down the pipe and expanded in place. Grout expands and penetrates the cracks and the stainless steel core completes the restoration.

Textile

Resin

Grouting Sleeve

rehabilitation alternatives - mi-wea.org technologies scholl.pdf · •the liners are resistant to...

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