Journal of Pipeline Systems Engineering and Practice

Pipe jacking is a technique used to construct tunnels by pushing prefabricated pipes through the ground from an entrance shaft to an exit shaft. This technique is referred as microtunneling in U.S. terminology, therefore, in the rest of the text, pipejacking and microtunneling will be used as having the same meaning. Pipe jacking is a more economical alternative to segmental lined tunnels. However, the main limitation of pipe jacking is the jacking distance, which is directly dependent on the friction between the pipe and the soil. Therefore, reducing the friction between the pipe and soil is a critical issue in terms of economy and construction speed. In pipe jacking, in order to reduce the friction between pipe and soil, a bentonite injection is applied. In this paper, a new laboratory test setup was prepared to simulate pipe jacking. The main aim of this test setup was to find the effects of bentonite pressure on the lubrication efficiency, which has not been clarified in the literature yet. In order to verify the test method, results of laboratory tests were compared with measurements of the friction between jacked pipe and soil in several real life projects. The measurements were compared with the coefficient of friction values obtained from three different field measurements conducted in different projects. According to the results, it can be stated that by applying continuous bentonite injection even under very low pressure, an interface can be created between bentonite slurry and a concrete pipe, and this bentonite interface is able to reduce the friction coefficient tremendously to approximately 10% of the sand–concrete pipe interface friction coefficient. But when the injection is not applied continuously, the application of bentonite slurry injection decreases the coefficient of friction to half of that in the case of no bentonite injection.

This work was motivated by the need for providing designers with more effective rehabilitation procedures. The initial step taken was to assess the ovality of the cross sections of thin-walled, cylindrical, high-pressure steel pipelines. Transition pipelines are exposed to the influences of combined loads (internal pressure, longitudinal force, and bending moment). These loads usually appear in places where hazardous conditions exist, such as landslides, soil subsidence, and changing temperatures, among others. Determining the ovality caused by meridian stresses after unloading the pipe sections is vital to the rehabilitation process. Internal pressure, bending moment, longitudinal force, and distribution of stresses and strains in the pipe cross section were analyzed using a new engineering approach to estimate the ovality after the unloading of the pipe element. A pipe with isotropic steel material properties in compressed and tensile hardening regions was considered. A stress-strain diagram of pipe materials was approximated using linear and power law. The approach consisted of two parts: investigation of beam-type load factors that cause elastic-plastic deformations in the pipe element without losing cross-sectional circular stability (ovalization), and determination of the radial and hoop displacements after loading and unloading. The theory of plasticity and the membrane theory of shells were used to reduce problems to the beamlike pipe. The results of the analytical study showed critical moment and curvature of the longitudinal pipe axis that correspond to maximum allowable ovality of the pipe. Variations of internal pressure during the pipe’s bending were compared with experimental outcomes.

One of the crucial issues regarding a storm sewer system is the ability to avoid sediment depositions on the pipe invert. In this study, the mean flow velocity under the limit of sediment deposition conditions in partially filled circular storm sewers is evaluated through the use of a support vector machine (SVM) model coupled with the firefly algorithm (FFA). The aforemetioned velocity, defined as the velocity at the limit of deposition, and the parameters upon which it depends have been nondimensionalized using the Buckingham $\mathrm{\Pi }$ theorem. Therefore, once the dimensionless parameters are identified, six different functional relationships in terms of dimensionless groups can be obtained. The effects of each of these functional relationships on the dimensionless velocity at limit of deposition, defined as the densimetric particle Froude number at the limit of deposition, have been analyzed by using, respectively, the SVM-FFA model, SVM model, genetic programming (GP) model, and artificial neural network (ANN) model. Five statistical indices have been used for evaluating the performance of each model (both in training and test phases) and, later, for comparing the performance of the different models between them. Finally, the predicted densimetric particle Froude number values obtained through the proposed SVM-FFA model have been compared with those obtained by three different dimensionless equations for velocity at the limit of deposition. The results indicate that SVM-FFA predicts the densimetric particle Froude number at limit of deposition fairly accurately.

A defect in a field-buried pipeline that has both a crack and a dent, commonly described as a dent-crack defect, may result in a devastating failure resulting from a rupture or leak in the dent defect. Hence, the safety and performance of a pipeline with a dent-crack defect becomes a significant concern for the operator. Recently, the University of Windsor’s Centre for Engineering Research in Pipelines completed a study examining this concern. The study examined the effect that crack length has on a pipeline’s burst strength or pressure capacity. This examination found that a dent-crack defect’s crack length of 300 mm may result in a 50% reduction in the pipe’s burst strength. This paper explains the examination setup, test specimens, and test procedure as well as the test data and the results garnered from finite-element analyses.

The traditional design-bid-build (DBB) delivery system is a sequential process and can lead to inefficiencies and adverse relationships among owners, design engineers, and contractors, which are often caused by a lack of stakeholder integration. Several alternative project delivery methods (APDM) have been introduced to increase stakeholder integration. Examples of these include construction manager at risk (CMAR), job order contracting (JOC), and design-build (DB). The ability to use alternative project delivery methods to deliver public construction projects is governed by legislation that may vary from state to state. A large and representative industry group working together out of Arizona State University (ASU) helped the State of Arizona revise its statutes in 2000 to allow municipalities, such as the City of Phoenix, to use alternative delivery methods (CMAR, JOC, and DB) for their construction projects. This paper studies the use of the CMAR delivery system by the City of Phoenix to deliver a critical 10-year pipeline rehabilitation program: the Val Vista water transmission main. This paper combines a case study and quantitative analysis of each of the four phases of the rehabilitation program. The findings demonstrate the performance benefits of using CMAR, which include a cumulative cost reduction of 2.75% and schedule reduction of 3.4% over the four phases of the program, as well as improved change and communication performance. This study offers a key contribution to the construction body of knowledge: it uncovers CMAR benefits through (1) performing a longitudinal study on a large-diameter water main rehabilitation program, and (2) analyzing the performance effects of the CMAR delivery method on pipeline rehabilitation. The results can help owners better understand the potential performance benefits CMAR has on pipeline engineering and construction projects.

Pipeline engineering provides practical input for the design, construction, and operations of a 0.6-m (24-in.) steam pipeline in a central city that may differ significantly from that for pipelines in other regions. A relatively short steam line is a critical, high-risk piece of infrastructure. When that pipeline threatens other utility service connections, it could cause hospital emergencies and area fatalities. Pipelines provide a vital service, and concern for the safety and welfare of the public has always been a focal point. The necessary activities and surface characteristics of city streets are key issues that challenge the field engineer for the pipeline installation. Specific project issues that necessitate consideration include temporary barricades, routing of traffic, slope stability, vehicular plating, and supports. This paper provides a case study that examines the field progress of a pipeline installation in one of New York City’s busiest areas and highlights the time spent overcoming key design issues and some of the technical developments of design, construction, and operations of steam supply pipe lines to high-rise office and residential buildings. Improving productivity in all the processes of pipeline construction is recognized as a pipeline engineering management problem that deserves attention.