August 9, 2016

Rerounding of Deflected Buried Pipe Subjected to Internal Pressure

This paper presents a theoretical basis for the rerounding effect of internal pressure on deflection and stresses in buried pipe. The nonlinear differential equations governing pipe-soil interaction of deflected buried flexible or semi-rigid pipe...

August 9, 2016

From Reactive to Proactive: A Pipeline Owner's Change in Philosophy

By: Rasko Ojdrovic, Anna Pridmore

Pipeline systems in power plants have a unique set of factors quite different from pipeline systems in municipalities. Typical municipalities have hundreds of miles of pipelines and focus on the inspection of this underground...

August 9, 2016

Forensic Analysis of a Large-Diameter Knife Gate Valve Performance

By: Rasko Ojdrovic, Christopher Trautner

Knife gate valves (KGVs) are frequently used in pipeline systems as on-off valves and to enable isolation and servicing of other system components. This type of valve operates by lowering a steel plate between two seal rings that are...

August 8, 2016

Evaluation of Unintended Live Load Effects on Buried Pipelines

Buried pipelines may be subjected to external live load effects not considered in the initial design during normal operation or during nearby construction activities. External live loads may be in the form of truck loads,...

August 8, 2016

Design of Concrete Pressure Pipelines for Thrust Restraint Using AWWA Manual M9

This paper details the procedure for pressure-induced thrust restraint design of concrete pressure pipelines with tied joints at elbows, tees, and end-caps through several examples following the current AWWA Manual of Practice M9. The paper...

August 5, 2016

Construction Dewatering: Understanding its effect on below-grade waterproofing

By: Daniel Gibbons, Payal Vora

Construction site dewatering is used to locally control and lower groundwater levels in the vicinity of the excavation. This is typically done to maintain soil conditions needed during, and occasionally after, construction—for example, to...

August 3, 2016

Evaluation of the Impact of Typical Imperfections in Hand-Applied CFRP Liners in Pressure Pipelines by Hydrostatic Testing

By: Rasko Ojdrovic, Murat Engindeniz, Nico Meyer, Scott Arnold

Fiber Reinforced Polymer (FRP) rehabilitation systems have validated efficacy in structural rehabilitation of pipelines since the first installation in the early 1990s. The hand applied layers of carbon and glass FRPs allow for time...

August 3, 2016

DC Water 22-Foot Brick Sewer Emergency Repair

By: Rasko Ojdrovic, Murat Engindeniz, Steve Bian, Anna Pridmore, Ben Deaton

In 2014, a five (5) story residential house was constructed in a residential area of Washington D.C. directly over the top of DC Water’s North East Boundary Trunk Sewer (NEBTS) without prior knowledge of DC Water. Based on the...

August 3, 2016

Discovery to Solution Implementation: NTMWD Addresses Degraded Piping under a Major Highway

By: Rasko Ojdrovic, Murat Engindeniz, Steven Long, Travis Markham, Mike Larson, Anna Pridmore

The North Texas Municipal Water District (NTMWD) is a water conservation and reclamation district created by an act of the Texas Legislature in 1951. Today NTMWD’s Regional Water System provides drinking water to over 1.6...

August 3, 2016

Evolution of the CFRP Repair of Pipelines—The Road to a Well-Established Technology

As with any technology, internal repair of pipelines using carbon fiber reinforced polymer (CFRP) composites has evolved since its first use in the United States in late 1990s, and the current state of the art in design, installation...