• Response of pressure pipes to differential ground movements
Outline: Differential ground movements imposed on buried pipes lead to lateral forces and longitudinal bending. The behaviour of cast iron, steel, PVC, HDPE and fibreglass pipes is being studied for ground movements imposed by frost, iceberg loads (offshore pipes), erosion voids, and faults arising during earthquakes. Analytical and experimental work is being used to understand stability limit states for buried infrastructure responding to frost loads. Thermo-viscoelastic analysis has been developed for HDPE to permit calculation of temperature-induced deformations or stresses. Three dimensional finite element analyses are being used to examine cast iron pipe damage as a result of differential ground movements caused by different levels of frost susceptibility. Reduced scale and prototype scale testing and three dimensional finite element analyses are being used to examine pipe response and soil-pipe interaction.
Funding: NSERC Discovery Grant, Discovery Accelerator Supplement, Strategic Research Grant, and Collaborative Research and Development Grant, Hamilton City, the Wood Group.
Collaborators : A. Fam, M. Green, B. Hawlader (MUN), S. Kenny (MUN), and A. Take
Duration: 2003 - present
Students: H. Mwana'gonze (MSc, 2004), S. Trickey (MSc, 2005), M. Balkaya (PhD, 2010), M. Sarai (PhD, 2011), M. Almahakeri (PhD, 2013), P. Ni (PhD, in progress), A. Burnett (MASc, in progress), E. Poon (MASc, in progress)
• Strength of Deteriorated Pipes and Repair Using Liners
liners fitted within damaged sewers will respond to external fluid loads,
and to changes in earth loads as a result of vehicle loads on the ground surface
or deterioration of the backfill in the vicinity of the buried structure.
Past work has established the role of damaged pipe and liner geometry on both
resistance to buckling under external fluid pressures, and local bending under
external earth pressures. Laboratory testing and nonlinear finite element
analysis is being used to understand how stability is influenced by erosion
voids in the vicinity of the buried sewer pipe. Limit states are now being
investigated for water and gas supply pipes repaired using cast in place liners,
considering the influence of internal pressure, ground movements and soil-pipe-liner
interaction. Large scale experiments are being used to establish the remaining
strength of corroded metal culverts, to establish the influence of soil voids
on culvert strength before and after repair, and to develop design methods
for a variety of culvert repair systems.
Funding: NSERC Discovery Grant, NSERC Strategic Research Grant, Hamilton City.
Collaborators : N. Hoult, A. Fam, D. Becerril Garcia, and E. Allouche (Louisiana Tech).
Duration: 1996 - present
Students: K. El Sawy (PhD, 1996), J. Lee (MSc, 2002) , M. Law (PhD, 2004), Z. Tan (MSc, 2007), N. Ampiah (MSc, 2008), M. Brown (PhD in progress), V. Mai (MASc, 2013), B. Simpson (MASc, 2013), J. Peter (MASc in progress) and C. Regier (MASc in progress).
• Pulling Forces and Hydraulic Fracture During Horizontal Directional Drilling
Outline: Horizontal directional drilling involves opening of a pilot hole using a horizontally directed drilling rig, hole expansion using a back-reamer, and pulling into place of a new HDPE pipe. Field measurements and finite element modeling are being used to investigate pulling forces on HDPE pipes pulled-into-place. Finite element studies are examining both blowout and brittle fracture of soil surrounding the borehole due to excessive mud pressures. Laboratory tests are being used to study hydrofracture in sands and clays.
Collaborators: E.N. Allouche (Louisiana Tech), and R.W. Brachman
Funding: NSERC Discovery and Strategic Research Grants
Duration: 1999 - present
Students: M. Baumert (PhD, 2003), M. Kennedy (MSc, 2004), A. Chehab (PhD, 2008) , H. Xia (PhD, 2008), J. Cholewa (PhD, 2009), H. Lan (PhD, in progress)
PAST ENGINEERING PROJECTS
Behaviour and design of reinforced concrete pipes
Outline: Large scale laboratory tests were used to examine the differences between direct and indirect design methods for these structures, adjustments to Direct Design were recommended to reconcile Direct Design with Indirect Design, and 'Talesnick' contact pressure sensors were used to measure earth pressures resulting from wheel loading. The use of uncompacted native fill to backfill reinforced concrete pipes was investigated through field tests and finite element analysis.
Collaborator: N. Hoult, E.N. Allouche (Louisiana Tech)
Funding: Ontario Concrete Pipe Association, NSERC Discovery Grant, US DOTs through the National Cooperative Highway Research Program
Duration: 2001 - 2014
Student: S. Wong (MESc, 2002), K. MacDougall (MASc, 2014)
Performance and design of piled foundations
Outline: Analysis methods were developed for tapered piles. Medium-scale tests were used to examine lateral earth pressures on piles responding to cyclic lateral loading.
Funding: ARC grant, NSERC Discovery Grant
Duration: 1991 - 2014
Personnel: Postdoc: J. Kodikara (1992), P. Oghabi (MASc, 2014)
Analysis of pipe and culvert coupling systems
Outline: Pipes used for stormwater sewers and highway culverts are fitted with a variety of mechanical and pressure rated couplings. The design of these couplings depends on the interaction of the two pipes, as well as the mechanical coupler and/or rubber gasket. Large scale laboratory testing was used to establish how soil-pipe interaction influences shear forces and rotations across pipe joints, and finite element analysis was developed for use in coupling design. Specific connection problems such as vertical forces at vertical risers have been investigated. Standard pipe joint tests are being developed to examine joint leakage, for the American Association of State Highway and Transportation Officials.
Funding: NSERC Discovery Grant, Ipex, US DOTs through the National Cooperative Highway Research Program.
Collaborators: D. Becerril Garcia, H. Sezen (Ohio State University)
Duration: 2002 - present
Students: J. Chan (MSc, 2002), J. Ye (PhD, 2008), M. Balkaya (PhD, 2010), D. Becerril Garcia (PhD, 2012), Y. Wang (MASc, 2013)
Soil-structure Interaction During HDPE Pipe Installation Using Pipe Bursting
Outline: Pipe bursting involves expansion to break and displace existing brittle pipes, and pulling into place of a replacement HDPE pressure pipe. Testing has provided detailed measurements of surface uplift resulting from pipe bursting in clays, sands and gravels. Analysis of the cavity expansion and contraction has been used to investigate radial pressures on the HDPE replacement pipe to permit estimation of pulling forces, peak stresses and maximum pulling lengths. Three dimensional finite element analysis has been used to develop parametric design solutions for ground movements, and the behaviour of adjacent pressure pipes.
Funding: NSERC Strategic Research and Discovery Grants
Collaborator: R.W. Brachman
Duration: 1999 - 2013
Student: V. Fernando (MESc, 2002), M. Nkemitag (PhD, 2007), B. Lapos (MSc, 2004), H. McLeod (MSc, 2008), J. Cholewa (PhD, 2009), K. Rahman (PhD, 2013)
Limit States Design of Large-Span Culverts
Outline: Analysis of field tests (conducted by Selig et al at UMass) was used to evaluate the effectiveness of 2D and 3D finite element analyses for calculating metal and concrete culvert response to earth and live loads. Design methods for the AASHTO Highway Bridge Design Code were developed using a parametric study conducted using the analyses. A 10m span deep corrugated metal culvert was tested in the laboratory up to its ultimate limit states. Three dimensional finite element analysis was used to model the service load and ultimate load response, and to develop new design methods for box and arch culverts.
Funding: NCHRP (US Academy of Sciences), NSERC Collaborative Research and Development Grant, Armtec Pty Ltd
Collaborators : R.W. Brachman, E.T. Selig (University of Massachusetts, Amherst MA), and T.G. McGrath (Simpson, Gumpertz and Heger, Arlington MA)
Duration: 1996 - 2009
Student: B. Taleb (PhD), A. Lougheed (MSc, 2008), T. Elshimi (PhD, 2011)
• Limit States Design of Thermoplastic Culverts
Outline: Laboratory testing to define limit states (local bending and local buckling), 2D and 3D finite element analysis and evaluations of published field studies are being used to develop design methods for high density polyethylene and polyvinyl chloride culvert products (being incorporated in the AASHTO Highway Bridge Design Code). New steel reinforced HDPE pipes have also been studied using laboratory testing and finite element analysis.
Funding: NCHRP (US Academy of Sciences), Contech Construction Products
Collaborators: T.G. McGrath at Simpson, Gumpertz and Heger, Arlington MA; R.W. Brachman, D. Sanders at Contech Construction Products.
Duration: 1999 - 2006
Students: A. Dhar (PhD , 2002), S. Munro (MSc, 2006)
• Analysis and Design of Loadout Tunnels Under Ore Stockpiles
Outline: Bulk solids are often removed from ore stockpiles using flexible metal or rigid concrete loadout tunnels. The design of the tunnels and the bulk-solids flow requires an assessment of earth pressures in and under the stockpiles. Finite element studies are being used to understand earth pressures during and after initial filling, unloading and refilling.
Collaborators: A. Roberts, and W. McBride, University of Newcastle (Australia)
Funding: NSERC Discovery Grant
Duration: 2000 -
Student: H.-Y. Jeong (PhD, 2005)
• Response of Silo Structures under Bulk Solid Loading.
Outline: Work has been conducted to compute the loads on silos when filled with bulk solids, assess the buckling strength under the action of vertical shear loads (taking into consideration the stabilizing effects of the bulk solid), and determine the shell response resulting from non-uniform solid-shell friction properties.
Funding: NSERC Collaborative Research Grant
Collaborators : J.M. Rotter and J.Y. Ooi, University of Edinburgh
Duration: 1994 - 1998
Students: J. Zhou (MESc, 1999) and M.T. Abdel-Fattah (PhD, 2001)
• Clogging of Drainage Systems for Municipal Solid Waste Landfills.
Outline: Work has been conducted to assess the impact of using large size gravel and large size perforations with plain HDPE leachate collection pipes to minimize biologically induced clogging. Testing and analysis was used to assess influence on local stresses in the HDPE pipe.
Funding: NSERC Collaborative Research Grant Collaborators : R.K. Rowe and others
Duration: 1994 - 2000
Students: R.W.I Brachman (PhD, 2000) and A. Tognon (MESc, 1999)
|Barrier Systems Project|