Recent earthquakes have highlighted the importance of earthquake ground motion recordings and rapid visual inspections (RVSs) of damaged buildings to assess the earthquake impact on the building inventory, prepare recovery plans, and provide valuable findings that could contribute to the preparedness ahead of future earthquake events. The effect of strong earthquake ground motions on the building stock is controlled by a range of interconnected factors. These include the intensity of ground motion, the effects of local soil conditions, the structural design, reinforcement and material properties, as well as the quality control during construction, among others. However, it is important to acknowledge that the earthquake ground motions recorded are dependent on local variables, such as the soil type and potential operational issues. Such an example is the major M6.4 earthquake in Durr & euml;s, Albania, in November 2019, the most significant in the region in the past four decades. The strong ground motion recorded at the sole Durr & euml;s accelerometric station was interrupted due to a power outage. As a result, the recorded accelerograms (with a PGA of 0.192 g) require thorough analysis and evaluation before they can be reliably used in assessing damage of existing structures. The current paper presents a framework for evaluating the incomplete record to ensure that the strong ground motion pulse is captured in the acceleration series. The latter is achieved by analyzing and comparing the amplitude and frequency contents of the recorded motion against ground motion accelerograms from areas with similar seismotectonic features. Ground motion recordings from stations that have soil conditions resembling those of the Durr & euml;s region are used, ensuring that the analysis is relevant to the specific study area. Next, the disrupted ground motion recording is evaluated by comparing the damage of post-earthquake inspected buildings with the results of advanced numerical analysis for the case of a typical 12-storey and a 5-storey building. The effects of pounding, the presence of infills, soil-structure interaction (SSI), and multiple failure modes are taken into consideration. Results indicate that despite the incomplete data, the seismic record retains the essential strong ground motion features and can be used for further studies. The numerical simulations aligned well with observed damage from rapid visual inspections, verifying the record's integrity. The findings show that factors such as soil-structure interaction, infill panels, and pounding effects significantly influenced building performance. The study concludes that the Durr & euml;s record, though incomplete, is reliable for seismic assessment and can aid future risk studies in the region.

To alleviate problems in urban living environments, an increasing number of shield tunnels have been built that go through rivers or underwater areas. Most of these tunnels experience leakage after a long period of operation, which can impact the safety of the tunnel and induce dangerous accidents, resulting in a loss of life and property. This paper reports the leakage characteristics during operation of a double-line ultralarge-diameter underwater shield tunnel that crosses the Yangtze River. After detailed geological surveys and field inspections of the prototype tunnel, the leakage characteristics and patterns of the tunnel were summarized based on long-term monitoring data. The distribution of leak-related defects was described in-depth with sketches and field photographs. Factors influencing the leakage of the prototype tunnel (i.e., the groundwater table, longitudinal settlement, and soil conditions) were interpreted based on field measurements. The mechanisms that triggered two typical leakage accidents that occurred during tunnel operation were systematically analyzed. The leakage mechanisms of the prototype tunnel were subsequently categorized into three patterns: joint leakage, bolt hole leakage and concrete crack leakage. Four countermeasures against leakage were proposed considering the leakage-associated damage to the prototype tunnel: backfill grouting, joint grouting, installation of a bolt hole sealing cover, and caulking gasket addition. The proposed mitigation measures were validated through laboratory tests and field applications. This unique tunnel prototype engineering case can provide a reference for water leakage prevention and control in the design, construction, and operation stages of similar underwater shield tunnel projects.

This paper introduces a novel framework for developing reliable probabilistic predictive corrosion growth models for buried steel pipelines using pipeline inspection data. The framework adopts a power -law function of time model formulation, accounting for nonconstant damage growth rates, and considers the correlation between defect depth and length growth models. The proposed framework explicitly incorporates local influential soil properties in the model formulation; thus, it requires no segmentation and homogenous defect growth assumption and provides defect -specific growth models. The framework is applicable regardless of the availability of matched or non -matched defect data. For corrosion initiation time estimation, two different approaches are proposed: one is to use a Poisson process to account for defect occurrence, which can also predict newly generated defects since the last inspection, and the other is to use multivariate linear regression of soil and pipe properties. The statistics of unknown model parameters are assessed using a Bayesian updating framework in which the model error can be incorporated. The proposed framework is applied using two different sets of data: one set of inline inspection (ILI) data and one set of field excavation data. A case study is conducted, where timedependent system reliability of an in-service pipeline is assessed considering small leak and burst failure modes using the developed defect growth models. The impact of the growth model accuracy on the probability of failure is investigated, and the importance analysis is performed to identify the most influential random variables to the probability of failure.

When operating in large drop pipelines, pipeline inspection gauge may experience severe impact vibration at elbows, potentially leading to its failure. This paper focuses on serial pipeline inspection gauges with multiple sections in large drop pipelines, analyzes the force acting on the pipeline inspection gauge during the descent phase, and establishes a multi-body dynamics model of the gauge under pipe-soil coupling conditions. In addition, a correction formula is developed for the pressure changes in the medium at the front and rear of the pipeline inspection gauge. To solve the model, MSC/ADAMS and MATLAB/Simulink are used for the bi-directional fluid-structure-interaction joint simulation. Moreover, the results are compared with the pipeline inspection gauge motion model established by OLGA. The study investigates the dynamic responses, vibration superposition and laws of dynamic evolution at the upper and lower elbows of the large drop pipeline. The results show that the speed of the gauge increases suddenly during the descent in large drop sections and then stabilizes, with different effects of the fluid medium pressure difference at various stages. The vibration responses along the axial, horizontal radial, and vertical directions at the elbows vary, with the second experiencing stronger vibrations due to superposition effects. Compared to fixed boundaries, the acceleration extremes of the gauge are lower under the constraints of pipe-soil model, indicating significant soil buffering and vibration damping effects.

Visual inspection and hammering tests are the standard methods for inspecting shield tunnels. They can provide a comprehensive judgment based on the engineer's past experience and conditions, such as cracking, water leakage, and structural details. However, one problem with this method is that the inspection results are highly dependent on the skills of the inspector. To overcome this limitation, it is necessary to develop an easy and quantitative inspection method for shield tunnels. The influence line (IL), which is the response at a specific point due to a unit load that is moved along the target structure, can be used for evaluating the soundness of the infrastructure. Therefore, in this study, we propose a method for determining the IL that can be applied when the speed of a passing train changes. The IL is determined by measuring the displacement due to the train load using a MEMS accelerometer. Finally, to verify the validity of the determined IL, a finite element analysis is performed. Good agreement is found between the ILs determined experimentally and analytically when the soil spring constant is 18 times higher than the nominal value, with a correlation coefficient of 0.98.

In view of the problem that the alignment of internal and external detection data mainly relies on manual verification and excavation verification, and can not make full use of mining detection information, feature information and mileage information are extracted from internal and external detection data as input and output variables, and the mapping relationship between them is established by using limit gradient lift (XGBoost) algorithm. Predict the outer detection mileage of the internal detection point, take the internal detection information as the benchmark, and use step by step translation to realize the alignment of the internal and external detection data, and conduct a comprehensive analysis according to the alignment results. The results show that the mileage error of all stations and valve chambers after data alignment is within 5m, the latitude and longitude distribution changes in the same height, and the alignment result points meet the accuracy requirements. In the example analysis, the degree of AC and DC interference of the pipeline is small, and the cathodic protection of the pipeline is normal. Although the soil corrosion is strong, there is metal loss and no obvious corrosion pits and corrosion products are found at the damage of the corrosion layer, indicating that the pipeline is in good running condition. The research results can provide theoretical basis for improving the level of pipeline integrity management.