GRAVITY SEWER REHABILITATIONCSEAO CONFERENCE, JUNE 5TH, 2017

V. Firat Sever, PhD, PE, BCEE

Goals of Sewer Rehab • Reduce/Eliminate Inflow

and Infiltration – Prevent Sanitary Sewer

Overflows (SSOs).– Reduce treatment plant flows

and operation costs.• Maintain structural integrity

of sewer system– Avoid catastrophic failures.– Prevent sewage backups

• Achieve regulatory compliance– EPA’s CMOM– Consent decrees

• Improve asset management

Funding Gap

Federal funding for wastewater infrastructure

CMOM

• Inspection coordination• Condition Assessment• Modeling• Defect/Impact Analysis• Decision Support Tools• Comprehensive assessment reports• Design• Maps/drawings (GIS or CAD)• Technical specifications

REGULATORY COMPLIANCECOST SAVINGS

Asset Management Condition

assessment/rehabilitation plan

WERF’s 10-step approach for water/wastewater facility asset management

Asset Management (contd.)

Adding Value to Sanitary Sewers

Rehab Decision Process Flow EVALUATE THE HYDRAULICS OF THE SYSTEM USING FIELD DATA/OBSERVATIONS AND

HYDRAULIC MODELING

INSPECT EACH PIPE SEGMENT WITH CCTV/SSET

ASSIGN A SCORE TO EACH DEFECT AND CALCULATE THE TOTAL CONDITION

SCORE

REVIEW INSPECTION REPORT AND CCTV VIDEO

IDENTIFY DEFECTS

IS UPSIZING NEEDED?

EVALUATE REPLACEMENT METHODS IS PIPE BURSTING

FEASIBLE/ECONOMICAL?

REPLACE TRENCHLESS BY BURSTING

RETRIEVE AND DOCUMENT INSPECTION

RECORDS

ASSIGN A COLOR CODE TO THE PIPE SEGMENT BASED ON CONDITION

IS RELINING (CIPP) FEASIBLE?

EVALUATE REPLACEMENT METHODS IS PIPE BURSTING

FEASIBLE/ECONOMICAL?

REPLACE TRENCHLESS BY BURSTING

REPLACE OPEN-CUT RELINE THE PIPE SEGMENT (EXAMPLE CIPP) REVIEW THE INSPECTION

RECORDS OVER

IS STRUCTURAL REHABILITATION

NECESSARY?

RELINE THE PIPE SEGMENT (EXAMPLE CIPP)

LIST THE DEFECTS AND DETERMINE DYSFUNCTIONS AND IMPACTS FOR EACH DEFECT

IS REHABILITATION NECESSARY?

LEAVE AS IS

IDENTIFY AVAILABLE TRENCHLESS POINT REPAIR

METHODS?

ASSIGN A METHOD (EXAMPLE CHEMICAL GROUTING, SEGMENTAL LINING) TO EACH DEFECT

LEAVE AS IS GREEN

RED

YELLOW

Evaluate hydraulic capacity

Identify defects and evaluate structural integrity

Economics and feasibility

YELLOW

RED

GREEN

LEAVE AS IS

OPEN-CUT POINT REPAIR

REHAB 100% TRENCHLESS (PREFERABLE)

CAN ALL THE DEFECTS BE REPAIRED BY TRENCHLESS TECHNOLOGIES?

ASSIGN A METHOD (EXAMPLE CHEMICAL GROUTING, SEGMENTAL LINING) TO EACH DEFECT

IDENTIFY AVAILABLE TRENCHLESS POINT REPAIR METHODS?

LEAVE AS IS

IS REHABILITATION NECESSARY?

LIST THE DEFECTS AND DETERMINE DYSFUNCTIONS AND IMPACTS FOR EACH DEFECT

RELINE THE PIPE SEGMENT (EXAMPLE CIPP)

IS STRUCTURAL REHABILITATION NECESSARY?

REVIEW THE INSPECTION RECORDS OVER

RELINE THE PIPE SEGMENT (EXAMPLE CIPP)

REPLACE OPEN-CUT

REPLACE TRENCHLESS BY BURSTING

IS PIPE BURSTING FEASIBLE/ECONOMICAL?

EVALUATE REPLACEMENT METHODS

IS RELINING (CIPP) FEASIBLE?

ASSIGN A COLOR CODE TO THE PIPE SEGMENT BASED ON CONDITION

RETRIEVE AND DOCUMENT INSPECTION RECORDS

REPLACE TRENCHLESS BY BURSTING

IS PIPE BURSTING FEASIBLE/ECONOMICAL?

EVALUATE REPLACEMENT METHODS

IS UPSIZING NEEDED?

IDENTIFY DEFECTS

REVIEW INSPECTION REPORT AND CCTV VIDEO

ASSIGN A SCORE TO EACH DEFECT AND CALCULATE THE TOTAL CONDITION SCORE

INSPECT EACH PIPE SEGMENT WITH CCTV/SSET

EVALUATE THE HYDRAULICS OF THE SYSTEM USING FIELD DATA/OBSERVATIONS AND HYDRAULIC MODELING

Sanitary Sewer Inspection

Man-Entry

Columbus LDA – Manhole Inspection w/ Pipetech™

PACP

• Pipeline Assessment and Certification Program

• 13 structural defect groups. More than 100 defect codes

PACP contd. PACP Code: Hole Void Visible (HVV)

Infiltration - Gusher

Structural Defects - Cracks

Structural Defects - Fractures

Corrosion (SAP)

Hole

Partial Failure

Collapse

Ovalization/Buckling

Rehabilitation Defects – Blistered Liner

FOG Buildup

Tree Roots

LACP

• Similar to PACP• Elaborate location

identification• Fittings

MACP

Manhole Defects – Displaced Frame

Manhole Defects – Corrosion

Manhole Defects – Failed Repair

Collapse

Keep small defects from becoming BIG problems!

Mapping / GIS

Inspection Progress Map

Business Risk ExposureThe picture can't be displayed.

BUSINESS RISK EXPOSURE = PROBABILITY OF FAILURE X CONSEQUENCES OF FAILURE

PresenterPresentation NotesPut a Structurepoint criticality map in the background

Criticality (contd.)

Rehabilitation - CIPP

Sliplining (Deform/Reform)

Geopolymer

Rigid Sliplining (GRP)

FRP Lining

PVC Panels

Rehabilitation Design

• Liner type and thickness matter• Loads (soil, groundwater, traffic,

other surcharge)• Environmental effects • ASTM F1216

– Empirical, partially / fully deteriorated design

Brick Conduits

Non-Circular Pipes

• Does ASTM F1216 work?

Manhole Rehabilitation

Manhole Rehabilitation contd.

WERF Project on Manhole Rehabilitation

Decision

Support Tool

Manhole Rehabilitation Material Classification

Experiments FEM

Expert Workshop

Literature Search

Case Studies

Main Test Participants

Strain Gage Installation

Main Tests (Stress vs. Strain)(1,100)

(900)

(700)

(500)

(300)

(100)

100

(170)(150)(130)(110)(90)(70)(50)(30)(10)1030

CMT2 CMT-EPX

PU1 PU2

PU3 EPX4

UNL

Strain [(in/in)x 10^-6)]

Stre

ss (p

si)

Finite Element Model – Hydrostatic Pressure on Liner

Finite Element Model (FEM) cont.

• Complete crushing test simulation on bare and lined samples

• Full-scale manhole modeling• Full-scale manhole

simulation with thinner wall• Full-scale manhole

simulation with deteriorated substrate (i.e. lower modulus of elasticity due to material degradation)

• Simulation for hydrostatic pressure on liner

Decision Support Tool (DST)

Enter MH condition

Enter soil properties

Enter groundwater

properties

Enter loads

Enter location information

Acceptable Structural Class and Materials

Acceptable Methods

Acceptable Classes, Materials, and

Rehabilitation Methods

Prepare technical

specification

Groundwater present?

Select the option with the lowest

price

Yes

No

Decision Support Tool ends here!

Enter MH condition

Acceptable Structural Class and Materials

Enter soil properties

Enter loads

Acceptable Classes, Materials, and Rehabilitation Methods

No

Groundwater present?

Enter groundwater properties

Yes

Select the option with the lowest price

Prepare technical specification

Enter location information

Acceptable Methods

DST – User Interface

User Interface created using Java Swing

Manhole Rehab Classification - Final

Manhole Rehabilitation

Materials

Structural (Class A) Semi-structural (Class B) Non-structural (Class C)

Polymer Concrete

Cured-in-place polymers (medium)

Cementitious lining (medium)

Fiberglass composite inserts

Cured-in-place polymers (thin)

Cementitious linings (thin)

Thermoplastic Sheets

Partial rehabilitation to stop I&I (e.g. chimney linings, grout sealants)

Cured-in-place (CIP) polymeric composites (steel reinforced)

Cured-in-place (CIP) polymeric composites

Cementitious lining (thick)

Cured-in-place polymers (thick)

Manhole Rehabilitation

Materials

Structural (Class A)

Semi-structural (Class B)

Non-structural (Class C)

Polymer

Concrete

Cured-in-place

polymers (medium)

Cementitious

lining (medium)

Fiberglass

composite

inserts

Cured-in-place

polymers (thin)

Cementitious

linings (thin)

Thermoplastic

Sheets

Partial rehabilitation to

stop I&I (e.g. chimney

linings, grout sealants)

Cured-in-place (CIP)

polymeric composites

(steel reinforced)

(steel reinforced)

Cured-in-place (CIP)

polymeric composites

Cementitious

lining (thick)

Cured-in-place

polymers (thick)

(Manhole RehabilitationMaterialsStructural (Class A)Semi-structural (Class B)Non-structural (Class C)Polymer ConcreteCured-in-place polymers (medium)Cementitious lining (medium)Fiberglass composite insertsCured-in-place polymers (thin)Cementitious linings (thin)Thermoplastic SheetsPartial rehabilitation to stop I&I (e.g. chimney linings, grout sealants)Cured-in-place (CIP) polymeric composites (steel reinforced)(steel reinforced)Cured-in-place (CIP) polymeric compositesCementitious lining (thick)Cured-in-place polymers (thick))

Manhole Rehab Cost

Conclusions

• Rehabilitation saves money• It does not always have to be fully-

structural• Criticality: Do it at the right place and right

time• No silver bullet: Always explore options• Use the right solution: Rehab design may

be complicated

Contact

Dr. Firat Sever, PE, BCEEfsever@structurepoint.com614-901-2235

GRAVITY SEWER REHABILITATIONGoals of Sewer Rehab Funding GapCMOMAsset Management Asset Management (contd.) Adding Value to Sanitary Sewers Rehab Decision Process FlowSanitary Sewer InspectionMan-Entry Columbus LDA – Manhole Inspection w/ Pipetech™PACPPACP contd. Infiltration - Gusher Structural Defects - Cracks Structural Defects - FracturesCorrosion (SAP) Hole Partial Failure Collapse Ovalization/BucklingRehabilitation Defects – Blistered LinerFOG Buildup Tree Roots LACP MACP Manhole Defects – Displaced Frame Manhole Defects – Corrosion Manhole Defects – Failed Repair CollapseMapping / GISInspection Progress MapBusiness Risk ExposureCriticality (contd.)Rehabilitation - CIPPSliplining (Deform/Reform)GeopolymerRigid Sliplining (GRP)FRP LiningPVC PanelsRehabilitation DesignBrick ConduitsNon-Circular PipesManhole RehabilitationManhole Rehabilitation contd.WERF Project on Manhole RehabilitationMain Test ParticipantsStrain Gage Installation Main Tests (Stress vs. Strain)Finite Element Model – Hydrostatic Pressure on Liner�Finite Element Model (FEM) cont.Decision Support Tool (DST)DST – User InterfaceManhole Rehab �Classification - FinalManhole Rehab CostConclusionsContact