A Characterization Method for Pavement Structural Condition Assessment based on the Distribution Parameter of the Vehicle Vibration Signal

A pavement structural survey plays a vital role in road maintenance and management. This study was intended to explore the feasibility of a non-stop pavement structure assessment method by analyzing the vibration data from a vehicle sensor. In this study, three falling weight deflectometer (FWD) tests and four vehicle vibration tests were conducted on five pavement structures. The FWD test results show that the continuously reinforced composite pavement has a higher structural stiffness than the semi-rigid base asphalt pavement. According to the statistical distribution of vehicle acceleration, a distribution parameter, the peak probability density (PPD), was proposed. The correlation coefficient (−0.722) of the center deflection (D1) and PPD indicates a strong correlation between the two variables. Therefore, PPD is strongly correlated with pavement structural stiffness. This study proposed a novel characterization method for pavement structural conditions based on the distribution parameter of the vehicle vibration signal.

Crack detection of concrete structures using deep convolutional neural networks optimized by enhanced chicken swarm algorithm

With the rapid increase of ageing infrastructures worldwide, effective and robust inspection techniques are highly demanding to evaluate structural conditions and residual lifetime. The damages on structural surfaces, for example, spalling, crack, rebar buckling and exposure, are important indicators to assess the structural condition. In fact, several state-of-the-art automated inspection techniques using these indicators have been developed to reduce human-conducted onsite inspection activities. However, the efficiency of these techniques is still required to be improved in terms of accuracy and computational cost. In this study, a vision-based crack diagnosis method is developed using deep convolutional neural network (DCNN) and enhanced chicken swarm algorithm (ECSA). A DCNN model is designed with a deep architecture, consisting of six convolutional layers, two pooling layers and three fully connected layers. To enhance the generalisation capacity of trained model, ECSA is introduced to optimize meta-parameters of the DCNN model. The model is trained and tested using image patches cropped from raw images obtained from damaged concrete samples. Finally, a comparative study on different crack detection techniques is conducted to evaluate performance of the proposed method via a group of statistical evaluation indicators.

Post-Earthquake Rapid Damage Assessment of Road Bridges in Glina County

In December 2020, a strong earthquake occurred in Northwestern Croatia with a magnitude of ML = 6.3. The epicenter of this earthquake was located in the town of Petrinja, about 50 km from Zagreb, and caused severe structural damage throughout Sisak-Moslavina county. One of the biggest problems after this earthquake was the structural condition of the bridges, especially since most of them had to be used immediately for demolition, rescue, and the transport of mobile housing units in the affected areas. Teams of civil engineers were quickly formed to assess the damage and structural viability of these bridges and take necessary actions to make them operational again. This paper presents the results of the rapid post-earthquake assessment for a total of eight bridges, all located in or around the city of Glina. For the assessment, a visual inspection was performed according to a previously established methodology. Although most of the inspected bridges were found to be deteriorated due to old age and lack of maintenance, very few of them showed serious damage from the earthquake, with only one bridge requiring immediate strengthening measures and use restrictions. These measurements are also presented in this paper.

Validation Of A New Method For Determining The Remaining Service Life Of Rigid Pavements

About a half of the Austrian highways are rigid pavement constructions, and increasingly more money has to be invested in their renovation and redevelopment. However, there are different approaches for the evaluation of the condition assessment of concrete pavements. The aim of the research presented in this paper is a concept for assessing the condition of a road section in rigid pavement. This consists of a structural and a visual assessment scheme for selecting appropriate maintenance actions. For the verification of this new method of assessment of the structural condition of concrete pavements, several field tests were examined. Furthermore, a case study was carried out to examine the level of influence of several input parameter. This analysis shows that the influence of the layer thickness is very high, while the influence of the modulus of elasticity of the existing concrete is significant lower. The FWD measurements were carried out radial (instead of linear) for the first time. The results show possible inhomogeneities in the subgrade or in the bedding, which would not be recognized by the standard linear measurements. With the results from the already mentioned measurements, the remaining service life of the test tracks could be calculated.

Evaluation of Structural Condition of Flexible Pavement Using The AASHTO 1993 and The MEPDG 2008 Method (Case Study: Cipatujah-Kalapagenep-Pangandaran National Road)

Flexible pavement on Cipatujah-Kalapagenep-Pangandaran National Road has a structural damage which marked by potholes and cracks on the pavement caused by excessive load trucks, so the pavement needs an overlay to improve the pavement condition. This analysis using AASHTO 1993 and MEPDG 2008 method. These methods used because the MEPDG 2008 was developed from AASHTO 1993 method, so the output will be more economic. But, the MEPDG 2008 has not applied yet in Indonesia, so the method will be studied to determine the method feasibility to be applied in Indonesia. This research was analyzed with two skenarios of CESAL, four trial thicknesses, and three CBR numbers. The overlay thickness value using the AASHTO 1993 was at 10 cm and 11 cm for scenario 1 and 2, while the overlay thickness using the MEPDG 2008 was at 10 cm for the two scenarios. The result from AASHTO 1993 was chosen because the MEPDG 2008 needs to studied further yet about suitable calibration factor for Indonesian pavement condition. The cause of difference result are structural damage assessment for AASHTO 1993 method based on deflection value from FWD while MEPDG 2008 method based on stresses and strains respond, material characteristics, and local calibration. Keywords: AASHTO 1993, MEPDG 2008, stress and strain response, FWD deflection value, local calibration factors, overlay thickness. Abstrak Perkerasan lentur jalan Nasional Cipatujah-Kalapagenep-Pangandaran mengalami kerusakan struktural yang ditandai dengan lubang dan retak pada perkerasan badan jalan yang disebabkan oleh truk pengangkut pasir yang memiliki beban berlebih, sehingga diperlukan penambahan tebal lapis tambah pada perkerasan jalan eksisting untuk mengembalikan kondisi kemantapan jalan. Dalam penelitian ini dilakukan analisis terhadap kondisi struktural perkerasan jalan lentur eksisting menggunakan Metoda AASHTO 1993 dan Metoda MEPDG 2008 dengan pertimbangan bahwa MEPDG 2008 merupakan pengembangan dari AASHTO 1993. Namun, Metoda MEPDG 2008 belum diterapkan di Indonesia, maka perlu dilakukan kajian awal untuk mengetahui kelayakan metoda tersebut diterapkan di Indonesia. Analisis ini menggunakan dua skenario nilai CESAL, empat macam tebal dan tiga macam nilai CBR. Berdasarkan hasil analisis, diperoleh tebal overlay menggunakan metoda AASHTO 1993 sebesar 10 cm dan 11 cm untuk skenario 1 dan 2, sedangkan tebal overlay menggunakan metoda MEPDG 2008 diperoleh tebal overlay sebesar 10 cm untuk kedua skenario. Namun dalam penelitian ini dipilih hasil dari metoda AASHTO 1993 dikarenakan MEPDG 2008 masih memerlukan kajian lanjut terkait faktor kalibrasi berdasarkan kondisi perkerasan di Indonesia. Dari penelitian diketahui faktor yang menyebabkan perbedaan hasil adalah Metoda AASHTO 1993 berdasarkan nilai lendutan FWD, sedangkan MEPDG 2008 berdasarkan respon tegangan dan regangan, karakteristik material, dan kalibrasi lokal. Kata-kata kunci: AASHTO 1993, MEPDG 2008, respon tegangan dan regangan, nilai defleksi FWD, faktor kalibrasi lokal, ketebalan lapisan.

A MODWT-Based Algorithm for the Identification and Removal of Jumps/Short-Term Distortions in Displacement Measurements Used for Structural Health Monitoring

Researchers have made substantial efforts to improve the measurement of structural reciprocal motion using radars in the last years. However, the signal-to-noise ratio of the radar’s received signal still plays an important role for long-term monitoring of structures that are susceptible to excessive vibration. Although the prolonged monitoring of structural deflections may provide paramount information for the assessment of structural condition, most of the existing structural health monitoring (SHM) works did not consider the challenges to handle long-term displacement measurements when the signal-to-noise ratio of the measurement is low. This may cause discontinuities in the detected reciprocal motion and can result in wrong assessments during the data analyses. This paper introduces a novel approach that uses a wavelet-based multi-resolution analysis to correct short-term distortions in the calculated displacements even when previously proposed denoising techniques are not effective. Experimental results are presented to validate and demonstrate the feasibility of the proposed algorithm. The advantages and limitations of the proposed approach are also discussed.

Assessing intermittent saline inflows in urban water systems

Urban water drainage systems' primary function is to transport sanitary or stormwater. The intrusion of saline waters has recognized detrimental effects. Especially in coastal areas, saline inflows can compromise performance by increasing the risk of untreated discharges, weakening the structural condition of concrete or metallic components, reducing the effectiveness of wastewater treatment processes and limiting the potential reuse for irrigation. Performance deterioration can be prevented by an early assessment of exposure to saline water, followed by timely actions to control its causes and consequences. The paper describes a procedure for diagnosing undue saline inflows. The procedure is based on the determination of saline inflow's magnitude, acceptance levels, and contribution to the system's performance. Contextual factors and performance indicators, and their reference values, are selected for the assessment. Options to address the problem are proposed, depending on the results. These options can relate to organizational, operational, and structural actions. Application to a case study allowed to validate the method and discuss the results. Here, saline volumes entering the system are quite relevant (almost 30%), posing problems regarding corrosion, treatment plant operation and significant concrete exposure to intermittent saline waters.

Effect of an endotoxicosis on the vegetative status of patients with chronic pancreatitis

Background. One of the defining typical clinical and pathogenetic syndromes of the formation and severity of chronic pancreatitis (CP) are the syndromes of endogenous intoxication (SEI) and autonomic (vegetative) dysfunction (VD). We did not find any studies of hematological indices of inflammation and intoxication, and especially in comparison with the parameters of vegetative status in CP, which motivated us to conduct this research work. The purpose of the study was to establish the relationship between hematological indices of inflammation and intoxication and the parameters of the autonomic status of patients with chronic pancreatitis. Materials and methods. We examined 69 patients diagnosed with CP who were treated as out-patient. The following hematological indices were determined: leukocyte intoxication index (LII), adaptation index (IA) with subsequent determination of the type of nonspecific adaptive response, lymphocyte-granulocyte index (ILG). The correlations of LII with the parameters of psycho-emotional state (neuroticism, reactive (RA) and personal (PA) anxiety according to the Eisenk, Spielberger-Khanin questionnaires), VD according to the Wayne questionnaire, and the duration of the disease were studied. Results. 63% of patients with chronic pancreatitis were diagnosed with endogenous intoxication of mild and moderate severity according to the Kalf-Khalif index, which makes it necessary to use drugs aimed at its correction. Significant correlations were established between LII and personal anxiety (direct weak r = 0.23, p <0.05), neuroticism (direct moderate force r = 0.41, p <0.05), autonomic dysfunction (direct weak r = 0,1, p <0,05), duration of the disease (direct weak r = 0,15, p <0,05), structural condition of the pancreas by ultrasound manifestations in points (direct weak r = 0.29, p <0.05), the level of α-amylase of the pancreas (direct medium strength r = 0.30, p <0.05). The obtained results proved the presence of significant interactions between the parameters of inflammation and endotoxicosis with indicators of autonomic status and the state of the pancreas. This makes it necessary to prescribe anti-inflammatory and vegetotropic drugs to patients with CP to enhance protocol treatment. Conclusions. Among patients with CP, favorable adaptive reactions were observed in only 36% of subjects, adverse - in 25%, intermediate - in 39%, and the average value of the adaptation index was - 0.48 ± 0.18, which corresponds to the upper limit of the orientation reaction. This motivates additional prescription of vegetotropic and adaptogenic drugs to such patients with CP. Only in 10% of patients with chronic pancreatitis the general immune response has no deviations from the adequate immune response, in 48% of subjects there is an inability of the immune system to complete inflammation, in 42% - the predominance of autoimmune intoxication, which requires enhanced anti-inflammatory therapy.