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In order to clarify the ultimate strength of the Pipe type Oil Filled (POF) steel pipe, the four-point bending test of a straight pipe was performed using buried pipes for power transmission, and the ultimate behavior related to bending deformation performance was confirmed. The straight pipe model under the condition of joint and axial force as parameters was tested, and the limit states against ovalization due to buckling of pipe were shown. Based on the experimental results, we performed finite element analysis (FEA) by detailed modeling for the four-point bending test of a straight pipe, confirmed the analysis accuracy, and showed that it was possible to evaluate even local deformation due to buckling. The test results were evaluated by the buckling strength formula of the cylindrical shell, it was confirmed that the maximum buckling strength can be assessed conservatively and rationally.

Demand for underground pipelines and the rehabilitation of existing utility infrastructure has been increasing due to urban expansion, continuous development, and the deterioration of exist...

The research on the map construction of pipeline environment is of great significance for the location of pipeline network, pipeline network planning and pipeline maintenance. It is an important development direction of underground pipeline detection technology to use robot to carry detection equipment into the pipeline to complete fault detection. In this paper, we propose a method of multi-robot collaborative mapping based on decentralized exploration and centralized mapping. The robot describes the pipeline information in the manner designed in this paper. The upper master gets the pipeline map information through single robot and then describes it by using geometry topology method. The simulation results shows that the final pipeline map are consistent with the actual pipeline map.

Advances in the field of material engineering, computerization, automation, and equipment miniaturization enable modernization of the existing technologies and development of new solutions for construction, inspection, and renovation of underground pipelines. Underground pipe installations are used in the energy sector, gas industry, telecommunications, water and sewage transport, heating, chemical industry, and environmental engineering. In order to build new pipeline networks, dig and no-dig techniques are used. Horizontal Directional Drilling (HDD) is one of the most popular trenchless technologies. The effectiveness of HDD technology application is mostly determined by its properly designed trajectory. Drilling failures and complications, which often accompany the application of the HDD technology, result from poor design of the well path in relation to the existing geological and drilling conditions. The article presented two concepts of Horizontal Directional Drilling well path trajectory design: Classic sectional, which is a combination of straight and curvilinear sections, and a single-section chain curve trajectory (catenary). Taking into account the advantages and disadvantages of the catenary trajectory relative to the sectional trajectory, the author&rsquo, s solution was presented, which was the implementation of the sectional trajectory with a maximum shape similarity to the catenary trajectory. The new approach allowed us to take advantage of a chain curve trajectory and was easier to implement using the available technology. The least squares method, based on deviations from a catenary trajectory, was set as the matching criterion. The process of searching for a trajectory, being a combination of straight and curvilinear sections as similar as possible to a catenary-type trajectory, was carried out using two methodologies: State space search and a genetic algorithm. The article shows the pros and cons of both optimization methodologies. Taking into account the technical and technological limitations of HDD drilling devices, a new approach was proposed, combining the methodology of state space search with the genetic algorithm. A calculation example showed the application of the proposed methodology in an engineering design process.

An inertial navigation system (INS) aided by odometers and a series of reference points has been extensively used to determine the location of pipeline inspection gauges (PIGs) in long-range gas and oil pipeline inspection. However, little attention has been paid to short-range urban underground pipeline surveying and the use of a low-cost inertial measurement unit (IMU) for location determination. The positioning performance of PIGs using low-cost microelectromechanical systems (MEMS) INS for short-range urban underground pipeline surveying applications has seldom been comprehensively evaluated. In this paper, we analyzed the positioning accuracy of a PIG based on a MEMS IMU and odometer through a real pipeline surveying case study. Numerous pipeline surveying cases, covering different pipeline lengths, pipe conditions, and surveying times, are included to achieve a practical conclusion with respect to the surveying accuracy. The results demonstrated that the maximum measurement repeatability errors of PIGs based on MEMS IMU and odometer do not exceed 0.25% and 0.1% of the pipeline length in the horizontal and vertical directions, respectively. These results not only provide powerful support for the PIG developers but also provide the expected PIG accuracy in urban underground pipeline surveying by using low-cost IMUs.

Components of transient resistance (TR) of underground pipelines are required during the design and control of their anti-corrosion protection and diagnostics of their technical condition. Disadvantages of traditional contact methods of measuring TR are shown. The new possibilities for determining the distribution of TR "pipe – earth" along the route and its components (resistivity of insulation, soil, polarization) on the pipeline sections by contactless measurements of currents and contact potentials measurements and taking into account the established connections between the components of electric field near underground pipeline are described.

The positions of the underground routing pipeline under conditions of the effect of the freeze-thaw processes in the permafrost soils are simulated in the paper. The change in seasonal temperatures leads to the emergence of thermokarsts, heaving and soil failures along the oil pipeline route, which negatively affects the performance of the object. The paper presents the calculation of 520 mm outer diameter (355 JR steel), 30 m length oil pipeline of underground routing (1.5 m depth of burial) in the permafrost soil conditions, which runs 25 ⁰C temperature oil under 5 MPa pressure, with 0 ⁰C temperature pipe casing. Modeling carried out in SolidWorks software using Simulation package. The stress-strain state and travels occurred during the seasonal changes in the soil are determined. According to the results of the study, the methods of reducing the influence of freezing and thawing processes to prevent the negative impact of mm soils on the oil pipeline are proposed.

Underground pipelines are vital means of transporting fluid resources like water, oil and gas. The process of locating buried pipelines of interest is an essential prerequisite for pipeline maintenance and repair. Acoustic pipe localization methods, as effective trenchless detection techniques, have been implemented in locating underground utilities and shown to be very promising in plastic pipeline localization. This paper presents a comprehensive review of current acoustic methods and recent advances in the localization of buried pipelines. Investigations are conducted from multiple perspectives including the wave propagation mechanism in buried pipe systems, the principles behind each method along with advantages and limitations, representative acoustic locators in commercial markets, the condition of buried pipes, as well as selection of preferred methods for locating pipelines based on the applicability of existing localization techniques. In addition, the key features of each method are summarized and suggestions for future work are proposed. Acoustic methods for locating underground pipelines have proven to be useful and effective supplements to existing localization techniques. It has been highlighted that the ability of acoustic methods to locate non-metallic objects should be of particular practical value. While this paper focuses on a specific application associated with pipeline localization, many acoustic methods are feasible across a wide range of underground infrastructures.

Cured-in-place linings (CIPLs) are flexible polymeric linings that can be used for the seismic retrofit of underground pipelines in situ. This paper focuses on the earthquake performance of 150-mm diameter pipelines with defects, such as weak joints and circumferential cracks, which are reinforced with CIPLs. The most critical mode of deformation is in the axial direction of the pipeline reinforced with linings. Full-scale tension tests show that CIPL de-bonding before rupture closely depends on the internal pipe pressure. The results of a finite element model accounting for CIPL de-bonding as a Mode II fracture propagation compare favorably with full-scale test results for different internal pressures. Quasi-static and dynamic tests on CIPL-reinforced pipes show that the CIPL can fail as the lining protrudes from a circumferential crack that opens and closes under transient ground motion, thus “pinching” off the lining. Simplified analytical and finite element models are used to calculate the peak ground velocity and periods leading to “pinching” failure. Recommendations are made for applying the findings of this study for the in situ strengthening of the underground pipelines.

The results of research on safety problems in underground pipeline transport are presented. It is shown that wear of main pipelines and equipment, as well as corrosion processes, are the main reasons that reduce the safety of using underground pipeline transport. Technical solutions have been developed to improve the reliability of pipeline transport and its security.

The magnetic flux leakage (MFL) type pipeline inspection gauge (PIG) is commonly used to detect defects on the underground pipelines as one of the nondestructive testing instruments. Although it is effective for the inter-city scale large size pipeline, it is hard to detect defects for the small size pipeline installed inside the city. So, it is necessary to adopt self-driving robot system to drive PIG module because the small gas pressure inside a small size pipeline is not enough to push PIG module. Even though it is enough to pass in straight line, when this module passes through bent pipe or welded pipe joint, the magnetic force between pipe and inspection module is increased sharply so that the PIG module could be stuck eventually. This paper proposed a new design structure of MFL system to decrease stuck forces on the pipe wall. All structural parameters for MFL sensors based on the magnetic field theory were designed to minimize the magnetic force and maximize the detection sensitivity of defect signals. The performance of the proposed system was verified by simulation results using 3-D finite-element method and experimental measured ones.

The stress-strain state of underground pipelines three-dimensional seismic loading in the form of a damped sinusoid is studied. The results of the variation of the normal and tangential stresses as well as the intensity of the normal and tangential stresses as a function of time, coordinate, and earthquake magnitude are presented.

Parallel and crossing pipelines are frequently implemented due to land-use restrictions and their ease of operation and maintenance. Given the proximity of these pipelines and the hazardousness of the substances they transport, an eventual Loss of Containment (LOC) in a parallel/crossing corridor can lead to a domino effect that should be considered in Quantitative Risk Analysis (QRA). For underground pipelines, this LOC is accompanied by a formation of a crater, which can uncover adjacent pipelines triggering a domino effect scenario to take place. This paper aims to develop a model to predict feasible crater dimensions (i.e., width and depth) from a LOC in underground natural gas pipelines using operational and structural parameters. For this purpose, a recent review of 57 underground natural gas pipeline accidents were considered in a probability-based approach once data was processed. This approach initially predicts the Width-to-Depth crater ratio (WD) using a multivariate regression. Then feasible crater dimensions were determined using the regression prediction interval and the width-depth joint probability function, which is approximated with a Gaussian copula. This approach proposes a worst, mean and less severe scenarios to support decision-making processes regarding parallel or crossing underground natural gas pipelines with a LOC. Besides the identification of domino effect scenarios, this information can be used to support pipeline segmentation for risk analysis or even to support Right-of-Way (ROW) definition during pipeline installation.

There have been revealed and summarized the regularities in biocorrosion of steel 17G1S-U, which is traditionally used for manufacturing oil and gas mains. The basic regularities of biocorrosion processes in the 17G1S-U pipe steel under the influence of SRB Desulfovibrio Sp. strains Kyiv-10 was obtained by weight-loss testing and surface analysis techniques. Effective inhibitors are proposed, which allow protecting steel 17G1S-U against the development of anaerobic corrosion under the influence of sulfate-reducing bacteria (SRB). The effectiveness of inhibitors is estimated by the degree of their protective effect. The porous structure of the surface film contributes to the initiation of localized corrosion. Damage analysis of the specimen surface corroded under different test conditions was performed.

The mechanism of the interaction of soil and an underground pipeline is studied in order to determine the load arising on the pipeline from the pressure due to the backfill soil and automobile traffic. A more accurate calculation is made of the coefficient accounting for the relief of the pipeline by the soil located in the recesses between the trench walls and the pipeline, and the deformation modulus of the backfill soil is evaluated. It is shown that the distribution of the compressive stresses arising in the soil as a result of the surface traffic is similar to that of a uniformly distributed load.

We consider the main concepts of evaluation of the general stability of underground pipelines according to the currently existing norms of Russian Federation. We analyze the main dependences that describe the interaction of pipes with soils in the transverse and longitudinal directions and are used in the software complexes intended for the design of main pipelines. The proposed solutions make it possible to substantially increase the accuracy of checking the total stability of underground pipelines in the longitudinal direction.

Prior research suggests that underground pipelines do not affect housing prices or that their adverse effects decrease over time. This paper examines an interesting case study where underground pipeline explosions cause negative effects that may persist over longer periods of time. Using an administrative population-based sample of housing transaction records in Taiwan, we estimate the effect of an underground pipeline explosion on housing prices in the island’s second-largest urban city. Overall, the underground pipeline explosion reduced housing prices by 2.9% in the following nine months after the explosion. The explosion directly decreased housing prices by 3.4% during the cleanup period (the first three months after the explosion). However, housing prices directly decreased by 4.9% during the recovery period (the fourth to ninth months after the explosion). We identify migration across districts as a potential mechanism responsible for the explosion’s effect on equilibrium housing prices.

The purpose of this article is to show a metallographic analysis of an underground pipeline taken out of operation upon failure. The pipeline had an 8.89 cm (3.5”) diameter and a 7 mm thickness. The study was based on a 45 cm long pipe sample, visibly and entirely corroded, with a fish-mouth crack along its length. The work contributes to finding new ways to prevent structural failure, which has high-impact consequences from the point of view of production, damage to property, pollution, and risks to human live. Through this analysis the knowledge on behavior of failures in terrestrial ducts has been extended. Development of the research included metallographic, chemical, and mechanical tests on the sample in order to know the composition of the material, its strength and its physical conditions upon taking it out of operation. After the analysis of the laboratory tests, the physical and chemical features were compared to existing national and international regulations, which allowed a specific characterization of the conditions of the sample. In accordance with the regulations, the grade of the pipe was between ×65 and ×70. Tensile testing was carried out to obtain mechanical properties in order to corroborate the grade of pipeline steel and complement the metallographic analysis.

Ground-penetrating radar (GPR) has become one of the key technologies in subsurface sensing and, in general, in nondestructive testing (NDT), since it is able to detect both metallic and nonmetallic targets. GPR has proven its ability to work in electromagnetic frequency range for subsoil investigations, and it is a risk-reduction strategy for surveying underground various targets and their identification and detection. This paper presents the results of a case study which exceeds the laboratory level being realized in the field in a real case where the scanning conditions are much more difficult using GPR signals for detecting and assessing underground drainage metallic pipes which cross an area with large buildings parallel to the riverbed. The two urban drainage pipes are detected based on GPR imaging. This provides an approximation of their location and depth which are convenient to find from the reconstructed profiles of both simulated and practical GPR signals. The processing of data recorded with GPR tools requires appropriate software for this type of measurement to detect between different reflections at multiple interfaces located at different depths below the surface. In addition to the radargrams recorded and processed with the software corresponding to a GPR device, the paper contains significant results obtained using techniques and algorithms of the processing and post-processing of the signals (background removal and migration) that gave us the opportunity to estimate the location, depth, and profile of pipes, placed into a concrete duct bank, under a structure with different layers, including pavement, with good accuracy.

The lithotechnical, natural-technical, and geoecological, rarely - natural-technical geoecological systems (NTGES), which refer to the material type, are the most popular in the geoecological research, according to the their purpose. Under the conditions of cryolithic zone of Western Siberia, one of the most dangerous NTGES is a system «objects of the gas transportation - environment», as it includes all the components of the environment and complex transportation infrastructure, which provides the main transportation of the gas and ties together the individual components of the gas complex, including the surface and underground pipelines, compressive and pumping stations, assosiated power lines and communication, storage, warehouses and domestic premises and others. A complexity of the NTGES’s behavior definition is in ability to see all thesystem in a whole, not breaking it in the components, for this it is reasonable to find the measure of its emergence.

Polyethylene (PE) insulations have a wide applicability in the insulation of both underground pipelines and underground power cables. In this context, by coupled techniques of thermal analysis (TG/DTG+DTA) and microbiological determinations, have been studied thermooxidability and resistance to moulds action of some polyethylene sorts. Following the processing of the experimental data obtained by thermal analysis it was found that during the applied heat treatment (100 grd C), in the first approx. 380 h, there is a growth of LDPE (low density polyethylene) polymerization degree by elongation of the aliphatic chains, after which the predominant process consists in the structure crosslinking. For MDPE (mean density polyethylene) samples, during the thermal treatment applied, it was found that the crosslinking degree of polyethylene (PE) increased without significant molecular weight change (with all the related consequences of increasing the weight of the tertiary and quaternary carbon atoms in the molecule). Microbiological determinations have highlighted that the resistance to filamentous fungal action of LPDE is higher than that of the investigated MDPE. It was found that after heat treatment applied (1000 h and 100 oC), both at LDPE and at MDPE, decreases the resistance to moulds action is decreased. It has also been found that moulds action resistance is substantially decreased when inoculated culture media and PE samples are exposed to an alternative electric field of 50 Hz - 6 Vrms/cm.

Land subsidence resulted in the loss of urban safe elevation, the tilt of buildings, and the damage of underground pipelines. It has been a big challenge to urban sustainable development.