Finite-Element Modeling of Failure of PCCP with Broken Wires Subjected to Combined Loads

Zarghamee, Mehdi S.; Eggers, Daniel W.; Ojdrovic, Rasko P.

doi:10.1061/40641(2002)66

Cited by 33 publications

(23 citation statements)

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“…The primary question to be answered through development of the risk assessment tool based on a PCCP design is how one could represent the number of wire breaks and their distribution within a PCCP. As part of the research program sponsored by the PCCP Users Group, Zarghamee et al (2002) performed hydrostatic tests and nonlinear finite element analyses to investigate the PCCP failure mechanisms under prestress loss attributable to wire breaks. Based on the findings from this research, Zarghamee et al (2003) presented a simplified analysis model to investigate failure margin in an embedded cylinder pipe (ECP) and proposed failure curves to assess the risk.…”

Section: Modeling Prestress Lossmentioning

confidence: 99%

Development of a Risk Assessment Tool for Managing PCCP Assets with Broken Wires

Rajah¹,

Plattsmier²,

McDonald³

et al. 2014

Pipelines 2014

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Aging pipeline infrastructure and limited funding for pipeline maintenance efforts make condition assessment an essential function in managing large-diameter pipeline assets for water agencies. Many of these pipelines are prestressed concrete cylinder pipe (PCCP) and, therefore, are subject to an elevated risk of failure attributable to prestressed wire breaks and continued corrosion of steel cylinders. Major water agencies must emphasize assessing and monitoring the PCCP pipelines' condition. Condition assessments should include: (1) determining the pipeline's structural condition by considering the number of wire breaks and the external and internal loads on the pipeline, (2) ranking the pipeline's condition, and (3) prioritizing maintenance needs.Based on past research supported by the PCCP Users Group and the American Concrete Pressure Pipe Association (ACPPA), the use of risk curves in PCCP asset management has been successfully demonstrated in the existing literature. However, given the complex structural analysis procedures required for the design of PCCP and the development of appropriate representations for wire break conditions, analysis tools for creating such risk curves have not been widely developed for practical applications.This paper presents a Microsoft Excel spreadsheet-based risk assessment tool developed by the primary author to perform structural analyses and to create risk curves based on condition assessment findings, including wire breaks detected through electromagnetic data and corrosion damage to cylinders obtained from internal and external pipeline inspection. The spreadsheet tool uses the structural analysis approach outlined in the current American Water Works Association (AWWA) C304 standard and historical C301 and C304 standards. The paper also presents an example of the tool's application to a risk-based condition assessment program.

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Section: Modeling Prestress Lossmentioning

confidence: 99%

Development of a Risk Assessment Tool for Managing PCCP Assets with Broken Wires

Rajah¹,

Plattsmier²,

McDonald³

et al. 2014

Pipelines 2014

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show abstract

“…al. [11] used a non-linear finite element model to predict the performance of PCCP with broken wires, and subjected to the combined effects of internal pressure, pipe and fluid weights and earth load as it loses prestress due to the gradually increasing number of broken wires. The model incorporated a non-linear stress-strain relationship for concrete that included nonlinearities due to compressive crushing, tensile softening and cracking.…”

Section: Introductionmentioning

confidence: 99%

“…The study showed that crack properties, pipe deflection, change in wire stress and concrete crushing are functions of the length of wire breaks. The results of the non-linear finite element analyses were used to validate engineering criteria and the procedures used for risk analysis and determining repair priorities for PCCP with broken wire wraps and for comparison with confirmation testing of such PCCP [11].…”

Section: Introductionmentioning

confidence: 99%

Effect of the location of broken wire wraps on the failure pressure of prestressed concrete cylinder pipes

Hajali

Alavinasab

Shdid

2015

Structural Concrete

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1 Introduction and backgroundPrestressed concrete cylinder pipe (PCCP) has been used for large-diameter water transmission and distribution mains in the United States as lined cylinder pipe (LCP) since 1942 and as embedded cylinder pipe (ECP) from 1952 onwards. Many classes of ECP have been standardized by the industry based on their internal fluid pressure capacity and backfill earth pressure capacity. The concrete core and prestressing wire are the main structural components, while the steel cylinder acts primarily as a water barrier. The prestressing wire wraps generate a uniform compressive force in the core that offsets the tensile stresses developed in the concrete due to the internal fluid pressure. A mortar or concrete coating surrounds the prestressing wire, embedding the wraps in an alkaline environment to protect them from external corrosive influences and physical damage such as corrosion. Breakage of prestressing wire wraps is a common occurrence in PCCP and is a result of damage due to corrosion, hydrogen embrittlement, overloading or manufacturing defects. Corrosion in immersed concrete structures can be due to earlyage cracks that leave paths for aggressive media, thus compromising the durability of the element [1], [2]. Corrosion and the subsequent breakage of an individual prestressing wire wrap reduces the strength of the pipe at that location [3]. If corrosion continues, multiple wire wrap breaks may occur in the same region, further reducing the strength of the pipe and leading to failure. Since this wire breakage is the primary cause of the structural deterioration of PCCP water mains, it is important to understand the effect of its length and location. The class of prestressing wire with its corresponding ultimate tensile strength is also an important factor for the overall strength of the pipe. Understanding the behaviour of PCCP under combined internal and external loading has gradually developed since the mid 1950s, and the evolution of the standards has been a direct result of investigations into PCCP failures [4], [5]. Although there have been significant improvements in the design and manufacture of PCCP, understanding damaged PCCP, which is intrinsic to this, is still under investigation. A study performed by Zarghami et al. [6], which compared experimental hydrostatic pressure test results with results from numerical FEM, found that the final failure mode for large-diameter PCCP was caused by increased stress in the prestressing wire wraps rather than crushing of the concrete. Liu et al.[2] presented a constitutive model for concrete hardening which considered the degree of hydration concept. The approach allowed the effects of both age and temperature on hydration to be taken into account simultaneously when modelling the early-age behaviour of underground precast concrete pipes. The study used the proposed numerical model to investigate the influences of mix design, casting scheme and curing conditions on the early-age behaviour of the pipes [2].Ojdrovic et al. [7] used finite ele...

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“…Diab and Bonierbale [18] created twodimensional and three-dimensional finite element models and developed effective repair procedures. Zarghamee et al [19][20][21] studied the characteristics of broken PCCPs with different diameters under combined loads using nonlinear finite element models. They empirically tested the failure modes and ultimate bearing capacity of a PCCP with broken prestressing wires to give probabilistic risk assessments for a PCCP with broken wires.…”

Section: Introductionmentioning

confidence: 99%

Using Externally Bonded CFRP to Repair a PCCP with Broken Wires under Combined Loads

Zhai

Fang

et al. 2019

International Journal of Polymer Science

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Prestressed concrete cylinder pipe (PCCP) is widely used for long-distance water pipelines throughout the world. However, prestressing wire breakage is the most common form of PCCP damage. For some pipelines that cannot be shut down, a new technique for in-service PCCP repair by externally bonding the pipe with layers of carbon fiber reinforced polymer (CFRP) was proposed. A set of three-dimensional finite element models of the repaired PCCP have been proposed and implemented in the ABAQUS software, which took into account the soil pressure, the weight of the PCCP, the weight of the water, and the hydrostatic pressure. The stress–strain features of the PCCP repaired with CFRP of various thicknesses were analyzed. The stress–strain features of different wire breakage rates for the repaired PCCP were also analyzed. The results showed that the strains and stresses decreased at the springline if the PCCP was repaired with CFRP, which improved the operation of the PCCP. It has been found that the wire breakage rates had a significant effect on the strains and stresses of each PCCP component, but CFRP failed to reach its potential tensile strength when other materials were broken.

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Finite-Element Modeling of Failure of PCCP with Broken Wires Subjected to Combined Loads

Cited by 33 publications

References 0 publications

Development of a Risk Assessment Tool for Managing PCCP Assets with Broken Wires

Development of a Risk Assessment Tool for Managing PCCP Assets with Broken Wires

Effect of the location of broken wire wraps on the failure pressure of prestressed concrete cylinder pipes

Using Externally Bonded CFRP to Repair a PCCP with Broken Wires under Combined Loads

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