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Introduction
Brad Parker Wham is an Assistant Research Professor and directs the Center for Infrastructure, Energy, and Space Testing at the Department of Civil, Environmental and Architectural Engineering (CEAE), University of Colorado Boulder. Dr. Wham performs research in Structural, Geotechnical, and Lifeline Engineering. His published work focuses generally on critical pipeline response to hazards such as earthquakes and construction-induced ground movements.
Additional affiliations
March 2019 - January 2021
Publications
Publications (81)
February 6th, 2023 M w 7.7 and M w 7.6 Kahramanmaras earthquakes caused severe damage to lifeline systems across 13 provinces in Turkiye and regions of Northern Syria. Impacts to water and wastewater infrastructure were significant, requiring the mobilization of support from across the region, and around the world to provide life-sustaining service...
The aging pipeline infrastructure around the world necessitates immediate rehabilitation. Internal replacement pipe (IRP) is a trenchless system offering a versatile and cost-effective solution across a variety of industries, including oil, natural gas, water, and wastewater. As a structural pipeline repair system, IRPs are subject to lateral defor...
Buried pipelines subjected to permanent ground deformations (through, e.g., earthquake-induced liquefaction or fault rupture) often experience widespread damage. Regardless of the direction of the demands, pipelines tend to respond and experience damage axially due to their directional stiffness characteristics. In addition, case studies and previo...
Buried pipelines need to withstand soil friction forces generated during relative movement between the soil and structure. The forces that develop along pipelines with diameter inconsistencies (i.e., with enlarged connections) are severely underestimated or ignored by current design practices. The movement of these enlarged connections can mobilize...
This paper presents the results of 1520, three-dimensional (3D), fully-coupled, effective-stress, finite-element simulations in OpenSees to evaluate the influence of a variety of intensity measures (IMs) on excess pore pressures and potential for surface ejecta in the free-field. The analyzed profiles showcase different layering, and vertical chang...
As legacy gas pipelines age, they often encounter issues. Pipe rehabilitation and replacement using internal pipes or liners is a trenchless approach to renewing issue-prone facilities. The analysis of recorded pipeline incidents of cast/wrought iron gas distribution mains revealed the causes of damage in host pipe systems. The leading cause of suc...
Shaking tables are widely used across numerous engineering research and industrial sectors, including mechanical (e.g. automotive and aerospace testing), electrical (e.g. instrumentation testing) and civil (e.g. structural and geotechnical testing) engineering. It is commonly required to replicate the shake table motions accurately and precisely. I...
The 2021 Marshall Fire was the costliest fire in Colorado's history and destroyed more than 1,000 homes and businesses. The disaster displaced over 40,000 people and damaged six public drinking water systems. A case study was developed to better understand decisions, resources, expertise, and response limitations during and after the wildfire. The...
This study focuses on the development of a pipeline performance classification for Axial Connection Force Capacity (CFC) to support the ongoing efforts of developing seismic design guidelines for water and wastewater systems. The only existing seismic design standard that includes a performance classification system for pipelines is ISO 16134. Whil...
Pipe-in-pipe (PIP) has become an acceptable system for the rehabilitation and repair of natural gas distribution networks. Damaged host pipes usually contain defects such as circumferential cracks which can affect the performance of the PIP systems. Under internal pressure, the PIP system will be in contact with the damaged pipes and may have an ad...
Different failure modes should be carefully analyzed to effectively design the pipe-in-pipe (PIP) repair systems to rehabilitate natural gas and water pipelines in place and in service. This study characterizes the failure modes through analytical and numerical modelling of the different performance objectives to have a comprehensive understanding...
Aging natural gas pipeline infrastructure needs rehabilitation, and trenchless, pipe-in-pipe (PIP) technologies offer a versatile solution. For example, legacy cast/wrought iron pipes have been subject to elevated incident rates for decades (www.phmsa.dot.gov). In an effort to accelerate innovation, the United States (U.S.) Department of Energy (DO...
Wildland urban interface (WUI) communities in the Western United States have recently dealt with historic and devastating wildfires year after year. The fires have cost tens of billions in damage, burned tens of thousands of structures, displaced thousands of residents, and killed hundreds of people. In particular, the 2017 Tubbs fire, 2018 Camp fi...
The presented study deals with a familiar situation when unsecured objects are transported in a vehicle. Unsecured objects have a character of objects dedicated to daily usage – work purposes or personal purposes. That generally means laptops, cell phones, tablets, drinks in a glass bottle, objects for sports, and others. Objects of interest are co...
Current efforts are underway to address buried pipeline susceptibility to damage from ground movements triggered by earthquakes, such as liquefaction-induced lateral spreading, landslides, and fault rupture. The linear nature of water and wastewater pipelines promotes failure due to ground displacement at locations of weakness, which for segmented...
Innovative hybrid-segmented pipeline systems are being used more frequently in practice to improve the performance of water distribution pipelines subjected to permanent ground deformation (PGD), such as seismic-induced landslides, soil lateral spreading, and fault rupture. These systems employ joints equipped with anti-pull-out restraints, providi...
Innovative hybrid-segmented pipeline systems are being used more frequently in practice to improve the performance of water distribution pipelines subjected to permanent ground deformation (PGD), such as seismic-induced landslides, soil lateral spreading, and fault rupture. These systems employ joints equipped with anti-pull-out restraints, providi...
Buried pipelines are susceptible to damage from large ground displacements imposed by natural hazards such as earthquake-induced fault rupture, landslides, and liquefaction-induced settlements and laterals spreads. A significant percentage of water and wastewater networks are composed of segmented pipelines that are particularly vulnerable at the c...
Dense granular columns (DGCs) are generally known to mitigate the liquefaction hazard through a combination of (1) installation-induced ground densification, (2) enhanced drainage, and (3) shear reinforcement. However, the relative contribution of these mitigation mechanisms remains poorly understood. A recent case history of successful embankment...
As water providers seek improved distribution system resilience to natural hazards such as seismically-induced fault rupture, landslides, liquefaction-induced lateral spreading, settlement, and other natural hazards, manufacturers have responded with innovative products incorporating improved materials and jointing mechanisms to accommodate large g...
In responding to the need for improved technologies to accommodate permanent ground deformation imposed by earthquakes, landslides, and other sources, a new family of segmented pipelines has emerged employing joints that displace axially and deflect before locking up and restraining further movement. Other than employing finite-element modeling, th...
Seismic damages of pipelines at fault crossing have been seen in various places in recent years. Countermeasures against fault offset are difficult, because the amount of fault offset on the order of several meters may occur locally. There have been virtually no cases in which proactive countermeasures were taken for fault crossings. Therefore, the...
Conventional buried pipelines used in water and wastewater systems are especially vulnerable to permanent ground deformation imposed by natural hazards such as earthquake-induced fault rupture and lateral spreading, flooding-induced scour, landsliding, and various
other sources of natural and construction-induced subsidence and settlement. Efforts...
Buried pipelines are susceptible to damage from ground movements triggered by earthquakes, such as liquefaction-induced lateral spreading, landslides, and fault rupture. Given the linear characteristics of water and wastewater pipelines, failure due to ground displacement is most likely to occur at locations of weakness, which for segmented pipelin...
Buried pipelines can be exposed to transient and permanent ground movements (e.g., lateral spreading, landslides, differential settlement, and fault rupture) in earthquakes. These movements can be characterized in terms of ground strain as a function of the ground displacement over the length or width which that displacement occurs. These ground st...
New segmented pipeline systems, with improved materials and jointing mechanisms , are being employed to address water distribution network vulnerability to seismically-triggered permanent ground movement such as liquefaction-induced lateral spreading and land-sliding. Contrary to their improved performance, these systems typically include connectio...
Large diameter steel pipe is a critical component of water transmission infrastructure
around the world and carries a significant percentage of consumed water in transmission
lines ranging in diameter from 0.6 m (24 in.) to 3. 7 m (144 in.). Failure of these large
diameter lifelines in areas of high seismicity can prove catastrophic by hindering fi...
This paper presents preliminary results from four centrifuge tests, performed at the University of Colorado Boulder, to evaluate the relative influence of different mitigation mechanisms provided by dense granular columns (DGC) on the seismic performance of embankments founded on liquefiable soil deposits. The first test was designed as the baselin...
The 2018 Hokkaido Eastern Iburi MW6.6 earthquake struck the southern coast of the north island of Japan in the early morning (3:08 AM JST) on September 6, 2018. The event had a hypocentral depth of 35 km, centered beneath the port city of Tomakomai. Extremely strong shaking with peak ground acceleration in excess of 0.5 g was felt in the communitie...
To address well-documented lifeline system vulnerability to ground deformation, a new generation of hazard-resilient pipeline products have been developed. These systems require evaluation for extreme loading conditions before they are accepted as viable options for design in hazard-prone regions. Presented is an experimental evaluation of a steel...
Cured-in-place linings (CIPLs) are flexible fiber-reinforced polymer linings used to rehabilitate aging pipelines in situ. They also can strengthen utilities against transient and permanent ground deformation caused by earthquakes, thus providing added value through seismic retrofitting. This paper presents the results of full-scale fault rupture t...
A new family of hybrid-segmented pipes is emerging into the international market which allow the joints to displace axially and deflect a prescribed quantity before locking up and restraining further movement. These pipe systems are mainly targeting improvement to earthquake-induced ground deformations, but also apply to other types of ground-induc...
Recognizing the need to improve the resilience of water distribution networks, water providers are seeking new technologies to accommodate ground deformation associated with seismically induced fault rupture, landslides, liquefaction-induced lateral spreading and settlement, and ground movements caused by other natural hazards, construction, mining...
This paper reports on a series of full-scale tests to evaluate the performance of seismic resistant, oriented polyvinyl chloride (PVCO) pipe. Earthquake resilience in water distribution networks requires pipelines that can accommodate fault rupture, liquefaction-induced lateral spreading, and subsidence. The implementation of hazard-resistant pipel...
The Kumamoto, Kyushu, Japan earthquakes began with an earthquake (M6.2) on the Hinagu Fault on April 14, 2016 followed by a second (M7.0) event on the Futagawa Fault, that on April 16. These shallow 10-11 deep km events are the strongest earthquakes recorded in Kyushu prefecture during the modern instrumental era. The United States' National Scienc...
Widespread damage to lifeline systems occurred as a result from the Kumamoto Earthquakes that initiated on April 14, 2016. Interruption to the water, gas, and electric power supply affected thousands of people. Landslides and surface rupture caused significant damage to transportation systems, especially roads and bridges. This paper provides an ov...
Pipeline susceptibility to ground deformation resulting from natural hazards, such as earthquake-induced surface rupture, lateral spreading and landslides, as well as construction related movements is well-documented. The present need to replace and retrofit existing infrastructure in high risk areas is being addressed through the introduction of a...
This paper focuses on the effect of tunneling-induced ground deformation on the response of jointed cast iron and ductile iron pipelines that (i) cross the settlement profile perpendicular to the tunnel centerline and (ii) connect through 90° tees with a pipeline parallel to the tunnel centerline. The modeling involves two-dimensional finite elemen...
Technological advances have improved pipeline capacity to accommodate large ground deformation associated with earthquakes, floods, landslides, tunneling, deep excavations, mining, and subsidence. The fabrication of polyvinyl chloride (PVC) piping, for example, can be modified by expanding PVC pipe stock to approximately twice its original diameter...
Technological advances have improved pipeline capacity to accommodate large ground deformation associated with earthquakes, floods, landslides, tunneling, deep excavations, mining, and subsidence. The fabrication of polyvinyl chloride (PVC) piping, for example, can be modified by expanding PVC pipe stock to approximately twice its original diameter...
The performance of segmental pipelines under large ground deformation is strongly influenced by the axial pullout and compressive load capacity of their joints, as well as by the limits on joint rotation during permanent and transient ground deformation. Although ductile iron (DI) pipelines with push-on joints are commonly used in water distributio...
Trenchless technology is well accepted for repairing critical underground lifelines with minimal ground surface disruption. The cured in place pipeline (CIPP) lining process is an application of trenchless technology that involves the installation of fiber reinforced composites inside existing pipelines. The uncertain performance of pipelines reinf...
In past earthquake events, the seismic vulnerability of underground pipelines caused significant life and economic losses. Seismic retrofit of critical underground pipelines has become an urgent need of our society to improve the performance and serviceability of these critical lifeline systems as well as to enhance public safety. The cured in plac...
The earthquake performance of segmental pipelines is strongly influenced by the axial pullout and compressive load capacity of their joints, as well as by the limits on joint rotation during permanent and transient ground deformation. Although ductile iron (DI) pipelines with push-on joints are commonly used in water distribution systems, experimen...
Thesis (Ph.D.)--Pennsylvania State College. Bibliography: pt.2, l.472-478. Microfilm (positive).