Amidst global scarcity, preventing pipeline failures in water distribution systems is crucial for maintaining a clean supply while conserving water resources. Numerous studies have modelled water pipeline deterioration; however, existing literature does not correctly understand the failure time prediction for individual water pipelines. Existing time-to-failure prediction models rely on available data, failing to provide insight into factors affecting a pipeline's remaining age until a break or leak occurs. The study systematically reviews factors influencing time-to-failure, prioritizes them using a magnitude-based fuzzy analytical hierarchy process, and compares results with expert opinion using an in-person Delphi survey. The final pipe-related prioritized failure factors include pipe geometry, material type, operating pressure, pipe age, failure history, pipeline installation, internal pressure, earth and traffic loads. The prioritized environment-related factors include soil properties, water quality, extreme weather events, temperature, and precipitation. Overall, this prioritization can assist practitioners and researchers in selecting features for time-based deterioration modelling. Effective time-to-failure deterioration modelling of water pipelines can create a more sustainable water infrastructure management protocol, enhancing decision-making for repair and rehabilitation. Such a system can significantly reduce non-revenue water and mitigate the socio-environmental impacts of pipeline ageing and damage.

Buried pipelines are essential for the safe and efficient transportation of energy products such as oil, gas, and various chemical fluids. However, these pipelines are highly vulnerable to ground movements caused by geohazards such as seismic faults, landslide, liquefaction-induced lateral spreading, and soil creep, which can result in potential pipeline failures such as leaks or explosions. Response prediction of buried pipelines under such movements is critical for ensuring structural integrity, mitigating environmental risks, and avoiding costly disruptions. As such, this study adopts a Physics-Informed Neural Networks (PINNs) approach, integrated with a transfer learning technique, to predict structural response (e.g., strain) of both unreinforced and reinforced steel pipes subjected to Permanent Ground Displacement (PGD). The PINN method offers a meshless, simulation-free alternative to traditional numerical methods such as Finite Element Method (FEM) and Finite Difference Method (FDM), while eliminating the need for training data, unlike conventional machine learning approaches. The analyses can provide useful information for in-service pipe integrity assessment and reinforcement, if needed. The accuracy of the predicted results is verified against Finite Element (FE) and Finite Difference (FD) methods, showcasing the capability of PINNs in accurately predicting displacement and strain fields in pipelines under geohazard-induced ground movement.

Open-ended pipe piles (OEPPs) are widely used in offshore foundations, yet accurately predicting their driving responses remains challenging due to soil plug complexities. Existing pile driving analysis models inadequately characterize the effects of soil plug, potentially leading to driving problems such as hammer refusal, pile running, and structural damage. This paper proposes an effective soil plug (ESP) model for OEPP driving analysis. The ESP model considers the effective range of soil plug, which exerts internal resistance that increases exponentially with depth while the beyond of effective range contributes only mass inertia. It also accounts for the relative slippage at the pile-soil plug interface. A differential iterative method is developed to solve the ESP model. Subsequently, investigations including the model validation and parameter analysis are conducted. Model validations against existing models and field measurements confirms the reliability of the ESP model. Parameters sensitivity analysis reveals the importance of soil plug length and distribution type of internal resistance on the pile dynamic responses. In addition, if soil plug slippage occurs, the displacement peak of soil plug increases with depth rather than one-dimensional wave attenuation. Furthermore, contrary to previous assumptions of continuous slippage, the soil plug experiences a discontinuous jump-sliding mode under long-duration impact loading. These findings provide theoretical basis for OEPP driving simulation and interpretations of high-strain dynamic test.

Iron pipes connected by bell-spigot joints are utilized in buried pipeline systems for urban water and gas supply networks. The joints are the weak points of buried iron pipelines, which are particularly vulnerable to damage from excessive axial opening during seismic motion. The axial joint opening, resulting from the relative soil displacement surrounding the pipeline, is an important indicator for the seismic response of buried iron pipelines. The spatial variability of soil properties has a significant influence on the seismic response of the site soil, which subsequently affects the seismic response of the buried iron pipeline. In this study, two-dimensional finite element models of a generic site with explicit consideration of random soil properties and random mechanical properties of pipeline joints were established to investigate the seismic response of the site soil and the buried pipeline, respectively. The numerical results show that with consideration of the spatial variability of soil properties, the maximum axial opening of pipeline joints increases by at least 61.7 %, compared to the deterministic case. Moreover, in the case considering the variability of pipeline-soil interactions and joint resistance, the spatial variability of soil properties remains the dominant factor influencing the seismic response of buried iron pipelines.

Buried pipes are subjected to static and dynamic loads depending on their areas of use. To mitigate the risk of damage caused by these effects, various materials and reinforcement methods are utilized. In this study, five buried uPVC pipes designed in accordance with ASTM D2321 standards were reinforced with three different ground improvement materials: Geocell, Geonet, and Geocomposite, and experimentally subjected to dynamic impact loading. Acceleration, velocity, and displacement values were obtained from the experiments. Subsequently, finite element analysis (FEA) was performed using the ABAQUS software to determine stress values and volumetric displacements in the pipes, and the model was validated with a 5-7% error margin. In the final stage of the study, a parametric analysis was conducted by modifying the soil cover height above the pipe and the Geocell thickness in the validated finite element model. The parametric study revealed that the displacement value in the pipe decreased by 78% with an increase in soil cover height, while a 16% reduction was observed with an increase in Geocell thickness. The results demonstrate that the soil improvement techniques examined in this study provide an effective solution for enhancing the impact resistance of buried pipeline systems.

Subsea pipelines in Arctic environments face the risk of damage from ice gouging, where drifting ice keels scour the seabed. To ensure pipeline integrity, burial using methods like ploughs, mechanical trenchers, jetting, or hydraulic dredging is the conventional protection method. Each method has capabilities and limitations, resulting in different trench profiles and backfill characteristics. This study investigates the influence of these trenching methods and their associated trench geometries on pipeline response and seabed failure mechanisms during ice gouging events. Using advanced large deformation finite element (LDFE) analyses with a Coupled Eulerian-Lagrangian (CEL) algorithm, the complex soil behavior, including strain-rate dependency and strainsoftening effects, is modeled. The simulations explicitly incorporate the pipeline, enabling a detailed analysis of its behavior under ice gouging loads. The simulations analyze subgouge soil displacement, pipeline displacement, strains, and ovalization. The findings reveal a direct correlation between increasing trench wall angle and width and the intensification of the backfill removal mechanism. Trench geometry significantly influences the pipeline's horizontal and vertical displacement, while axial displacement and ovalization are less affected. This study emphasizes the crucial role of trenching technique selection and trench shape design in mitigating the risks of ice gouging, highlighting the value of numerical modeling in optimizing pipeline protection strategies in these challenging environments.

Buried water pipelines, as crucial urban infrastructure, play an essential role. However, the damage to the pipeline structure has emerged as a severe public safety hazard. Monitoring the state of the pipeline structure holds great significance for the normal operation of water pipelines. In this paper, a damage monitoring method for buried pipelines based on distributed acoustic sensing technology is proposed. Through a series of field experiments conducted on a pipeline, the feasibility of utilizing the attached fiber-optic cable to acquire vibration information has been demonstrated. The recorded vibration signals can indicate various damage statuses during the pipeline damage process, including rock/soil fall, pipeline seepage, and pipe wall failure. The results suggest that the fiber-optic cable accompanying the pipelines can be exploited as sensing resources to monitor damage risks to the pipelines, which presents advantages in the damage identification and location of buried pipelines. This research provides a valuable reference for the application of distributed acoustic sensing technology in the damage monitoring of urban buried water pipelines.

Frequent road collapses caused by water leakages from pipelines pose a severe threat to urban safety and the wellbeing of city residents. Limited research has been conducted on the relationship between pipeline leakage and soil settlement, thus resulting in a lack of mathematical models that accurately describe the soil settlement process resulting from water erosion. In this study, we developed an equation for pipeline leakage, conducted physical model experiments on road collapses induced by drainage pipeline leakage, investigated the functional relationship between drainage pipeline leakage and soil settlement, and validated this relationship through physical experiments with pipelines of various sizes. The results indicated that drainage pipeline leakage triggered internal erosion and damaged the soil layers in four stages: soil particle detachment, seepage channel formation, void development, and road collapse. When the pipeline size was increased by a factor of 1.14, the total duration of road collapse induced by pipeline leakage increased by 20.78%, and the total leakage water volume increased by 33.5%. The Pearson correlation coefficient between the theoretical and actual settlement exceeded 0.9, thus demonstrating the reasonableness and effectiveness of the proposed settlement calculation method. The findings of this study serve as a basis for monitoring soil settlement and issuing early road collapse warnings.

The nonlinear mechanical behaviour of pipeline joints influences the seismic response of water supply pipelines. This study presents an experimental investigation of the tensile behaviour of push-on joints of ductile iron (DI) pipelines, subjected to axial tensile forces and internal water pressure. The axial performance and damage states of joints are determined for push-on joints with different diameters. A statistical analysis is then conducted to determine the correlation between tensile strength and joint opening. An empirical equation for estimating the tensile strength of pipeline joints is proposed, along with a normalized failure criterion for joint opening considering water leakage. Moreover, a numerical model for buried pipelines considering nonlinear soil-pipe interaction is developed. Incremental dynamic analysis (IDA) is performed on DI pipelines with explicit consideration of the uncertainty of joint mechanical properties. Seismic fragility curves are developed based on the IDA results. The effect of mechanical parameter uncertainty of pipeline joints on seismic risk assessment of segmented pipelines is quantitatively evaluated. The numerical results indicated that the failure probability of the pipeline considering the uncertainty of joint mechanical properties is approximately 1.5 to 2 times larger than that predicted by a deterministic model.

Ultrasonic guided waves are widely used in the nondestructive testing (NDT) of aboveground pipelines. However, their application in buried pipeline inspection is significantly hindered by severe soil-induced attenuation. This study proposes a method for detecting defects in buried pipelines using nonlinear chirp signals encoded with orthogonal complementary Golay code pairs. By adjusting the proportion of low-frequency and high-frequency components in the excitation signal, the attenuation of guided waves in buried pipelines is effectively reduced. Meanwhile, the use of coded sequences increases the energy of the excitation signal, and the excellent autocorrelation properties of broadband signals enhance the time-domain resolution of defect echoes. The fundamental principles of coded excitation based on nonlinear chirp signals and pulse compression methods are first introduced. MATLAB simulations are then employed to verify the approach's effectiveness in the characterization of defect echoes under various conditions and signal-to-noise ratios (SNR). A subsequent comparative analysis, using finite element (FE) simulations for buried pipelines, demonstrates that nonlinear chirp signals with a higher proportion of low-frequency components exhibit better resistance to attenuation. By fine-tuning the chirp parameters, higher defect reflectivity can be achieved than with conventional tone bursts for various defect types in buried pipelines. FE simulations further illustrate the superiority of the proposed method over tone bursts in terms of excitation signal amplitude, defect echo reflectivity, and defect location accuracy. Finally, defect detection experiments on buried pipelines with multiple defects confirm that the nonlinear chirp signals with carefully selected parameters exhibit lower attenuation rates. In the same testing environment, the coded nonlinear chirp signals outperform tone bursts by providing higher excitation amplitudes, greater defect echo reflectivity with an increase of up to 81.45 percent, and enhanced time-domain resolution. The proposed method effectively reduces ultrasonic guided wave attenuation in buried pipelines while increasing defect echo reflectivity and extending the effective detection range.