Journal of Pipeline Systems Engineering and Practice

The pipeline inspection gauges (PIGs) are often blocked in actual operation. As the PIG ran in the straight pipeline, elbow, and anomaly, the large deformation and stress state of the power section cup were analyzed by a three-dimensional (3D) finite element (FE) simulation to provide a basis for solving the blockage problems. A rubber cylinder model was first established to simulate the interference fit to the pipeline. Numerical and analytical results were compared to verify the accuracy of the numerical method. Based on this method, the power section model with four cups was established and the contact-pair algorithm was adopted in order to simulate PIGs running in different locations of the pipeline. The radial stress and strain were subsequently obtained. Results show that when the PIG runs in a straight pipeline the radial stress of the outer edge of the cup is evenly distributed, and when the PIG runs in the elbow and anomaly the radial stress of the outer edge of the cup indicates a cardioid distribution.

Sensor networks have gained tremendous appreciation in recent years and have been successfully tested in various application scenarios such as disaster management, pipeline monitoring, and environmental monitoring, as well as different military and security-based applications. In order to protect pipelines from leakage and corrosion, various conventional methods and techniques are used for monitoring. Functioning only in a specific environment, these conventional techniques require special infrastructure and higher maintenance. These challenges could, however, be overcome efficiently by using wireless sensors and robots. Most previous surveys mainly focused on the hardware design of the sensors, basic sensing techniques, and transmission media, but overlooked conducting an exclusive survey of pipeline monitoring schemes using linearly deployed wireless sensor networks or robots. This study attempts to carry out an extensive survey on the factors affecting pipeline monitoring techniques and provides novel classification in terms of classifying them into different strategies, sensor types, sensing coverage, communication methods, and monitoring types. In addition, a survey of comparative analysis of existing pipeline monitoring techniques is also presented, and general pipeline monitoring methods are also compared and summarized. Moreover, the need to explore pipeline monitoring schemes that incorporate wireless sensor networks (WSNs) is highlighted because WSNs are easy to deploy and flexible enough to be installed in any environment. This study discovers that most existing pipeline monitoring schemes that do not deploy sensors in a linear direction, which ultimately increases the cost and reduces overall network performance. Finally, several unresolved issues occurring in the development of pipeline monitoring techniques are highlighted, and future directions are provided accordingly.

Currently, corroded corrugated steel culverts are typically assessed based on the results of visual inspections that provide qualitative data about corrosion levels. However, there is a lack of experimental data relating the extent of corrosion to the capacity of the culvert that would allow engineers to assess the remaining capacity and also the end-of-service-life condition for deteriorated culverts (answering the question, how much deterioration is too much?). To address this need, a series of experiments were conducted on culverts with varying levels of corrosion and two levels of soil cover (0.45 and 0.9 m) subjected to simulated vehicle loading. The results of the experiments indicate that backfill compaction plays a more significant role in the behavior of deteriorated pipes than corrosion for most levels of deterioration. For example, the control pipe (with no corrosion) was not the stiffest pipe and developed significant bending moments under service loading rather than carrying the loads in thrust, which was believed to be the result of poor backfill. The most deteriorated specimen that was tested to failure, with 34% remaining wall thickness at the water line, failed because of local buckling of the remaining strips of steel between perforations in the wall in the corroded region. However, a specimen with 47% remaining wall thickness failed because of the formation of plastic hinges in the top half of the culvert, suggesting that the failure was unrelated to the corrosion. These preliminary results suggest that there is a critical level of corrosion that causes a reduction in capacity but that the condition of the surrounding soil has a significant influence on the ultimate capacity and that the two cannot be assessed independently.

Underground freight transportation (UFT) is a class of automated transportation systems in which vehicles carry freight through tunnels or pipelines under roadways between intermodal terminals. The UFT systems increase the current freight movement capacity and alleviate the problems associated with the fast growing need for freight transportation. Despite the inherent UFT benefits to alleviate traffic congestion and enhance safety and security of freight transportation while improving sustainability, a detailed lifecycle benefit-cost analysis is yet required to explicitly show planners and decision makers the economic feasibility of such systems. The primary objective of this paper is to conduct a comprehensive lifecycle benefit-cost analysis of linear induction motor-based UFT systems for five different scenarios. This methodology includes the following steps: (1) developing UFT scenarios with different sizes (small, medium, and large) and routes (short and long) in collaboration with a stakeholder committee; (2) determining lifecycle cash flows; (3) calculating net present values, benefit-cost ratios, and internal rates of returns; (4) conducting sensitivity analysis; and (5) performing breakeven analysis. The results of this research show that the highest benefits of the UFT systems are revenue from shipment and reduction in air pollution. The internal rates of return, benefit-cost ratios, and net present values of the UFT scenarios indicate that the benefits offset the costs of the system. Results of sensitivity analysis show that the economic feasibility of the large and medium-size UFTs is more sensitive to tunnel construction cost and revenue from shipments. They also indicate that the economic feasibility of the UFT system with a short route and small size is more sensitive to higher discount rates and the policies concerning the shipment pricing. Results of breakeven analysis highlight a shorter payback period for the large and medium-size UFTs compared with small-size scenarios. The results show that the price of shipment for all the UFT scenarios is highly competitive compared with the current price of shipment by trucks.

As the number of deteriorated infrastructure assets, including culverts, continues to rise, there is a need to find the most cost-effective approaches to dealing with these assets. At the same time, there is a growing awareness that decisions cannot be made exclusively based on cost and that sustainability must also be considered. Although there exist a number of tools that allow environmental, societal, economic, and technical considerations to be assessed when evaluating alternatives for many infrastructure projects, there is no such tool for culverts. This paper describes the development of a culvert module for a commercially available assessment tool known as GoldSET. The environmental, societal, economic, and technical indicators used within the culvert module are introduced and described. The use of the tool is then demonstrated using two case studies that assess the viability of a traditional open-cut approach compared to trenchless approaches. For the two selected case studies, the trenchless approaches are found to be preferable except if considerations of technical uncertainties dominate the decision making.

This paper investigates the condition of polyethylene (PE) pipelines as a case study. This study introduces a novel method to detect and diagnose defects of high-density polyethylene (HDPE) pipes. The pipe defect detector technique (PDDT) is designed to capture and process the images from the inner surface of pipes. Consequently, PDDT is one of the nondestructive ways to investigate possible defects in pipes. The PDDT’s outcome offers valuable information regarding the shape, orientation, and length of defects in the inner surface of the pipe. This information plays an important role in defining the lifetime of the pipe and fault prediction. In this paper, a database consisting of a total 350 images was used to train, test, and verify a neural network system. For this purpose, input image quality was enhanced by applying Gabor and entropy filters. Then, the trained neural network was used to classify the input images into five defect categories. These categories are defined in a way to describe the shape and the orientation of the defects. Afterward, a curve completion method (CMM) that effectively derives the defect dimensions such as diameter and length was introduced. Finally, the life prediction methods that can use PDDT’s result to predict the time that actual fault may occur in the pipe are discussed.

Analyses of well-documented field instrumentation data from two deep excavations in Shanghai soft ground indicate that displacements of shallowly buried pipelines caused by adjacent excavation are predominantly governed by the locations of the pipelines relative to the pits and are much less affected by pipeline flexural rigidity or soil bedding stiffness. On average, circular excavations produce much smaller pipeline settlement ($u_y<0.16\%H_e$) than do rectangular excavations ($u_y\le 0.42–0.46\%H_e$), where $u_y$ and $H_e$ denote pipeline settlement and final excavation depth, respectively. Despite this discrepancy, $u_y$ of pipelines behind corners of rectangular pits behave similarly to those behind circular excavations in terms of both magnitude and settlement profile. For pipelines parallel to rectangular excavations, their $u_y$ exhibit obvious corner stiffening behavior, i.e., the $u_y$ near the pit middle span is as much as to 9 times the $u_y$ near the pit corner. Consistent with ground settlement, primary $u_y$ is observed at those pipelines buried within the zone approximately $0.5–1.5H_e$ behind the retaining wall for both circular and rectangular excavations. Compared with $u_y$, the corresponding lateral pipeline displacement, $u_x$, is much smaller, less than $0.16\%H_e$. Furthermore, the magnitudes of $u_x$ along pit sides are independent of the distance from the pit corners and more closely related to lateral displacements of adjacent retaining walls. Based upon regression analyses on amounts of field measurements, empirical formulas are developed for estimating adjacent excavation-caused $u_x$ and $u_y$. Once the location of the pipeline relative to the pit, $H_e$, and pit geometry are known, both $u_x$ and $u_y$ corresponding to different intermediate excavation levels, $H$, can be reasonably predicted.

Freight transportation by trucks plays a significant role in the economy of a region, and at the same time contributes greatly to the deterioration of roads and highways. The majority of goods shipped in Texas are carried by trucks or by services that use trucks for part of the delivery. Construction of new intermodal transportation systems, such as underground freight transportation (UFT) systems by using underground tubes or tunnels for moving goods can mitigate the need for road widening or building new roads in areas bogged down by truck traffic. However, the gap between public service needs and the financial capabilities of the state governments has grown, and financing innovative infrastructure projects, such as UFT systems, has become increasingly challenging. Successful implementation of a large UFT system demands availability of appropriate funding sources. The objective of this paper is to identify and evaluate viable funding sources and appraise the eligibility of these sources for constructing UFT systems in Texas. An extensive literature review, analysis of codes and legislation, and case study analyses were used to achieve the research objectives. This research identified a variety of public and private funding sources, such as federal, state, and local funds, Transportation Infrastructure Finance and Innovation Act (TIFIA) loans, funds provided under the Fixing America’s Surface Transportation Act (FAST Act), revenue bonds, private activity bonds, and equity participation for financing UFT systems. The results highlight significant opportunities to qualify UFT projects with state or national significance for federal funding eligibility. It is also possible to identify UFT systems as projects that alleviate traffic congestion and improve safety to be eligible for Texas state funding programs.

To transfer petroleum products, a common pipeline is often used to continuously transfer various products in batches. Separating the different products requires detecting the interface between the batches at the storage facilities or pump stations along the pipelines. The conventional technique to detect the product in the pipeline is to sample the fluid in a laboratory and perform an offline measurement of its physical characteristics. The measurement requires sophisticated laboratory equipment and can be time-consuming and susceptible to human error. In this paper, for performing the online detection and separation of the batches, two methods are suggested that do not need extra equipment and are more practical. Because different petroleum products have different densities, the goal of both methods was to estimate the density of each product to detect its type. To estimate the fluid density, the first method used a recursive Kalman filtering algorithm and a model that defined the relationship among the pump’s differential pressure, the volume flow rate, and the rotational speed. The second method was suggested for the cases when the measurement of pressure and flow rate are not possible but the motor current and rotational speed are directly measurable. For that purpose, first the load torque was estimated. Then, by using a model that has parameters that depend on the density and that defines the relationship between the required pump torque and its rotational speed, the parameters of this model and consequently the density of the fluid were estimated.