Heavy Vehicle Loads Research Articles

Influence depth of highway subgrade under heavy vehicle loads based on a theoretical model

A three-dimensional dynamic model of vehicle-road-unsaturated subgrade coupling is established. The semi-analytical and numerical solutions of three-dimensional dynamic response of highway subgrade under vehicle load are presented for the first time. Then, the accuracy of the theoretical model is verified by the field measurement data. Finally, the spatial distribution of dynamic stress and depth of working zone under different influencing factors are studied, and the calculation model of depth of working zone of highway subgrade is proposed. The results show that the dynamic stresses, σx, σy, σz, and τxz increase significantly with the increase of vehicle axle load and decrease significantly with the increase of road thickness under the same subgrade depth. In addition, with the increase of axle load and the decrease of road thickness, the peak values of dynamic stress σx, σy, σz, and τxz decrease more obviously along the depth of roadbed. In the process of vehicle movement, the traditional subgrade working area can be divided into a sensitive area and an influence area of dynamic load. The depth of these two areas is positively correlated with the axle load of the vehicle and negatively correlated with the thickness of the road surface. The advantage of the model in this paper is that the semi-analytical solution of the total stress component of the soil element in the course of traffic load is given.

Effect of Vehicle Load on the Fatigue Cracks of the Center-stay for a Steel Girder Deck in a Suspension Bridge

Steel deck systems are widely used in cable-stayed and suspension bridges because of their various advantages. However, the direct effect of vehicle loads often leads to fatigue cracks in steel decks, particularly at the intersections of the longitudinal and transverse ribs, which have been the focus of most studies. In the target bridge of this study, unlike the location where fatigue cracking generally occurs, cracks were detected in the vertical stiffener inside the stiffening girder just below the center-stay and that adjacent to the center-stay. A precise analysis was performed to determine the cause of fatigue cracking, and the analysis model was verified by comparing it with the results of an existing load test. This study examined the effects of heavy vehicle loads by adjusting the vehicle weight and changing the position of the vehicle. This study confirms that as the vehicle load increases, fatigue cracing may occur in the internal vertical stiffener of the center-stay stiffening girder, leading to subseuent cracs in the external center-stay.

A bridge dynamic response analysis and load recognition method using traffic imaging

As the primary variable load of bridges, vehicle load is an important parameter for bridge health monitoring. However, traditional Weigh-in-Motion (WIM) systems and the commonly used method of placing sensors on the bridge are challenging to apply in load monitoring for many small and medium-sized bridges. Therefore, this paper proposes a bridge vehicle load identification method based on traffic surveillance video data. Leveraging the surveillance video data on the bridge, without introducing additional hardware devices, the displacement of target points is detected through sub-pixel level image detection algorithms, enabling non-contact measurement of bridge structural response through imaging. A spatiotemporal relationship model of structural displacement, vehicle load, and load distribution is established to solve for vehicle load. Finally, model bridge tests under various loading conditions and engineering practice experiments are conducted to validate the feasibility of the method. The results of the model bridge tests show that the structural displacement measured using traffic video measurement has a deviation of less than 10% compared to the measurements obtained using contact displacement sensors (LVDT), and it can accurately reflect the displacement characteristics of the structure. The results of the field tests demonstrate that the average estimation deviation for heavy vehicle loads ranging from 12 to 18 tons is approximately 18%, meeting the engineering requirements. The proposed method can provide load statistical information for the extensive health monitoring of small and medium-sized bridges and offer a new technical pathway for obtaining bridge load information.

Stability Analysis of Open-Pit Bench Slope under Repeated Heavy Vehicle Loading Based on Stress-Corrosion Model

In the present study, we address an important and increasingly relevant topic in mining safety and efficiency, namely the stability of open-pit bench slopes subjected to daily heavy truck cyclic loading. Specifically, we focus on the stability of Zhahanur open-pit slope (Inner Mongolia region, China) and investigate the potential role of daily heavy truck cyclic loading in bench slope instability. To this end, we incorporate a stress corrosion model into the particle flow code to develop a time-dependent deformation model of the rock. With the established model, we quantitatively analyse the effect of heavy truck cyclic loading on the bench slope stability. Our results support the hypothesis that daily heavy truck loading can cause gradual downward deformation of a rock mass, leading to slope instability. To validate our numerical modelling results, we compare and analyse them with in situ monitoring data. Our study demonstrates the significant impact of daily heavy vehicles on bench slope stability in open-pit mines and provides a practical tool for assessing the long-term stability of open-pit bench slopes and optimising mining operations.

Evaluation of mechanical properties of paver blocks by replacing cement with fly ash and marble waste

Paver blocks (PB) play a pivotal role in various construction and infrastructure works providing aesthetically and durable pleasing surfaces for various applications such as pavements, walkways, and driveways. These blocks can be used for heavy vehicle loads instead of low-strength clay bricks and tiles. PB gained focus in the construction industry due to its multi-advantages like high strength, durability, and low maintenance cost. However, due to the usage of cement, its application is limited, which releases a huge amount of carbon dioxide into the ecosystem. Thus, it leads to global warming and climate change. In addition, cement is one of the expensive materials used in PB, which further reduces the interest of the construction industry and end-users of PB. Marble waste as its excessive amount of generation from stones in industry and fly ash as a byproduct from coal combustion immediate opportunities to use these materials and reduce the impact of waste material on the environment. Therefore, this study aims to reduce cement consumption by partially replacing marble waste and fly ash combinedly. The study contributes practically to the use of alternative materials in the construction industry. Three types of samples namely M1 (replacement with marble waste), M2 (replacement with fly ash), and M3 (replacement with both fly ash and marble waste) were used. Various proportions were added as a partial replacement, the replacement varying from 5 to 30%, which was 5%, 10%, 15%, 20%, 25%, and 30%. Statistical analyses were carried out for interpretations of the data. The result concluded that all three mixes achieved their maximum compressive strength on different days of curing. M1-15 and M3-20 mixes achieved maximum compressive strength related to control specimens at 56 days. However, the M2-20 mix achieved maximum compressive strength at 7, 28, and 56 days, The maximum flexural strength was recorded by the M1–15 mix at 7 and 56 days, while the M2–20 and M3–20 mix achieved maximum flexural strength at 7, 28 and 56 days. ANOVA tests by one-way indicate that there is no difference in the mean of compressive strength however, there is a difference in the mean of flexural strength. The Tukey post hoc analysis shows a statistically significant difference between all levels of days of compressive and flexural strength, except for some levels of compressive strength. The correlation test results indicate a positive and strong association between all three mixes.

Analysis of the extent of heavy vehicle overloading on Namibian trunk roads and evaluation of the effectiveness of existing mitigation measures

Overloading of heavy vehicles reduces pavement life and increases pavement life cycle costs. As part of Namibia's strategy to control heavy vehicle overloading on the road network, weighbridge facilities have been constructed at strategic locations on primary routes (trunk roads). The study analysed the extent of heavy vehicle overloading on Namibian trunk roads, as well as the effectiveness of existing overloading mitigation measures. The dataset comprised heavy vehicle loading information from the year 2015 to 2019, from ten static weighbridge facilities. The parameters investigated include overloading magnitude, the effect of overloading on road pavement life, and the effectiveness of current overload mitigation measures. The results showed that 13.3% of the vehicles weighed were overloaded, with a compounded decrease in overloading of approximately 0.5% per annum. Despite the overloading decrease, the study found that the estimated road service life was reduced by as much as nine years over the study period. High levels of weighbridge avoidance and poor stakeholder coordination in mitigating overloading were identified. The study recommends deploying high-speed weigh-in-motion systems, an increase in fines charged for overloading offenses, and developing a demerit point-based system for habitual offenders to strengthen mitigation measures.

A deep learning method for heavy vehicle load identification using structural dynamic response

The identification of dynamic vehicle loads is crucial for bridge health monitoring. Currently, bridge weigh-in-motion (BWIM) system and image recognition methods are extensively used for vehicle load identification. However, BWIM systems are costly, while single image recognition methods struggle to accurately identify vehicle weight. Hence, an improved approach is proposed to address the above issues, which employs a Bidirectional Long Short-Term Memory (BiLSTM) network model to establish the mapping relationship between vertical deflection of bridges and vehicle loads. Firstly, based on practical engineering, the Grey Wolf Optimization-Variational Mode Decomposition (GWO-VMD) method is employed to address the influence of temperature effects on deflection response data. Then, through a time matching algorithm, the sliced deflection data and the corresponding BWIM system vehicle load information are paired to form the dataset for the deep learning models. The results of the models demonstrate that the optimal BiLSTM model exhibits better robustness and generalization performance. It achieves high accuracy of 97.9% in load identification. The method significantly reduces the economic cost and improves the accuracy of vehicle load identification.

A Hierarchical Trajectory Planning Algorithm for Automated Guided Vehicles in Construction Sites

Herein, to address the challenges faced by Automatic Guided Vehicles (AGVs) in construction site environments, including heavy vehicle loads, extensive road search areas, and randomly distributed obstacles, this paper presents a hierarchical trajectory planning algorithm that combines coarse planning and precise planning. In the first-level coarse planning, lateral and longitudinal sampling is performed based on road environment constraints. A multi-criteria cost function is designed, taking into account factors such as deviation from the road centerline, shortest path cost, and obstacle collision safety cost. An efficient dynamic programming algorithm is used to obtain the optimal path. Considering nonholonomic constraints of vehicles, eliminating inflection points using improved B-Spline path fitting, and a quadratic programming algorithm is proposed to enhance path smoothness, completing the coarse planning algorithm. In the second-level precise planning, the coarse planning path is used as a reference line, and small-range sampling is conducted based on AGV motion constraints, including lateral displacement and longitudinal velocity. Lateral and longitudinal polynomials are constructed. To address the impact of randomly appearing obstacles on vehicle stability and safety, an evaluation function is designed, considering factors such as jerk and acceleration. The optimal trajectory is determined through collision detection, ensuring both safe obstacle avoidance and AGV smoothness. Experimental results demonstrate the effectiveness of this method in solving the path planning challenges faced by AGVs in construction site environments characterized by heavy vehicle loads, extensive road search areas, and randomly distributed obstacles.

Research on the Damage Mechanics Model of Asphalt Pavement Based on Asphalt Pavement Potential Damage Index

In recent years, due to the increasing traffic volume and the serious deterioration of overloading, the heavy vehicle load has emerged, leading to the more and more common early damage of asphalt pavement, and overloading has become one of the important factors endangering the pavement. The traditional method is to strengthen the road, but as the base course and asphalt pavement thickness are both improved, TOP-DOWN fissures and ruts on the asphalt pavement surface have emerged as the most prevalent form of asphalt pavement damage. However, a final verdict on a single mechanical explanation for the many occurrences of asphalt pavement deterioration has not yet been reached. Material yielding and failure under varying stress conditions are the focus of strength theory, which seeks to provide norms and standards for their computation. Mohr Coulomb and Drucker Prager strength theories are two of the most well-established, thoroughly investigated, and widely used strength theories in geological and geotechnical engineering. In this research, the damage form and stress condition of asphalt pavement are analyzed and predicted using M-C and D-P criteria, and a new pavement structure damage control index, the Asphalt pavement potential damage index with fatigue loading (APPDI), is established. Preliminary calculations reveal that APPDI may become a unified mechanical assessment index of asphalt pavement structural damage, since it can explain both flexural tensile damage at the base of the layer and rutting and cracking at the surface.

The mechanical deformation characteristics of the internal structure of large diameter shield tunnel in different construction stages

PurposeUnder the repeated action of the construction load, opening deformation and disturbed deformation occurred at the precast box culvert joints of the shield tunnel. The objective of this paper is to investigate the effect of construction vehicle loading on the mechanical deformation characteristics of the internal structure of a large-diameter shield tunnel during the entire construction period.Design/methodology/approachThe structural response of the prefabricated internal structure under heavy construction vehicle loads at four different construction stages (prefabricated box culvert installation, curved lining cast-in-place, lane slab installation and pavement structure casting) was analyzed through field tests and ABAQUS (finite element analysis software) numerical simulation.FindingsHeavy construction vehicles can cause significant mechanical impacts on the internal structure, as the construction phase progresses, the integrity of the internal structure with the tunnel section increases. The vertical and horizontal deformation of the internal structure is significantly reduced, and the overall stress level of the internal structure is reduced. The bolts connecting the precast box culvert have the maximum stress at the initial stage of construction, as the construction proceeds the stress distribution among the bolts gradually becomes uniform.Originality/valueThis study can provide a reference for the design model, theoretical analysis and construction technology of the internal structure during the construction of large-diameter tunnel projects.

Experimental Study on the Mechanical Properties of Reinforced Pervious Concrete

Pervious concrete (PC) has gained popularity as an environmentally friendly solution for mitigating the urban heat island effect and promoting sustainable construction. However, its lower compressive strength, attributed to its higher porosity required for permeability, poses challenges for withstanding heavy vehicle loads on pavements. Our study aims to improve the flexural strength of regular PC by adding advanced reinforcing materials like steel wire mesh or glass fiber mesh. This results in reinforced pervious concrete, referred to as RPC, which offers enhanced strength and durability. The primary objective of our research is to investigate the mechanical behavior of RPC, with a specific emphasis on essential design parameters such as PC elastic modulus, modulus of rupture, and stress–strain characteristics under both single and repeated loading conditions. Our findings reveal that the influence of repeated loading on the compressive strength and elastic modulus of PC pavement is negligible, as there are no significant differences observed between the two loading protocols. Notably, our statistical analysis indicates that the PC strength (fc′) averages around 15 MPa. Moreover, empirical formulas for the elastic modulus (Ec = 3072fc′) and modulus of rupture (fr = 0.86fc′) are derived from our research. Furthermore, our study establishes that the stress–strain behavior of PC closely aligns with the general concrete model proposed by a previous scholar, providing valuable insights into the material’s structural performance. These findings contribute to a better understanding of RPC’s mechanical properties and offer potential solutions for improving its suitability for heavier vehicular loads.

EFFECTS OF LOADING MASS ECCENTRICITIES ON UNSPRUNG MASS ROTATIONAL DYNAMIC RESPONSES OF HEAVY VEHICLE ON IRREGULAR ROAD PAVEMENT

Using individual independent unsprung masses in suspension system modeling is not a realistic reflection of vehicle dynamics in response to eccentric wheel kinematics and asymmetric heavy vehicle loading. This is because the use of such masses does not accurately represent the unsprung mass system's influence on heavy vehicles' dynamics, including its impact on the sprung masses or wheel pavement dynamic loading. This study aims to examine how heavy vehicle asymmetric loading and wheels' eccentric kinematic excitation affect the rotational dynamic response of the unsprung masses. A total of 450 models were used to investigate various asymmetrical cases, from which 9 3D 24 DOF heavy vehicles' 4 DOF rear tandem drive axle suspension systems were selected for analysis using SIMWISE 4D. These vehicles were tested for a pothole depth of 25 mm and a vehicle translational speed of 60 km/h. The study found that the nature of the pavement distress factor (kinematic excitation) determines the suspension's rotational dynamic response and, consequently, the sprung mass. Moreover, the load distribution on the sprung mass also affects the rotational dynamic response of the tandem beams

Analysis of dynamic response of three-span bridge using vehicle load data from Road Administration Department IV in Vietnam

In many studies, the dynamic response of bridges is influenced by various factors. Multiple factors, such as vehicle loads, road roughness, vehicle-bridge interactions, and travel speed, impact the dynamics of a three-span bridge on highways. Because the mass of the vehicle, including the cargo, fluctuates randomly, a probabilistic methodology based on the Monte Carlo method is utilized to produce random anomalies for dynamic analysis. To examine the Song Gieng bridge, data from the Road Administration Department IV on heavy vehicle loads and overloaded vehicles are utilized to produce random vehicle loads. The analytical results indicate that there is a discrepancy in the probability distribution rules between the vehicle load (input random variable) and the dynamic impact factor (output random variable). This implies that their mapping connection is not monotone. Compared with the threshold values specified in the bridge design standards of Vietnam and the United States, the dynamic impact factor obtained in this study is significantly different. These findings can provide additional guidance for practicing engineers.

Monitoring and Simulating the Responses of Four Flexible Pavement Test Sections under Heavy Vehicle Loading

Abstract For mechanistic-empirical design of pavements, it is essential to accurately predict the responses of the structure that are caused by the design traffic loading. The aim of this study was to compare the simulated responses of pavements with real measurements under heavy vehicle loading. With this objective, four instrumented test sections were built in northern Sweden—about 100 km north of the Arctic Circle. These test sections differed in material quality of the various layers. Each test section was instrumented with pressure cells and strain sensors that measured the pavement response to external loading. Climatic variables were monitored through a weather station as well as temperature and moisture sensors installed in the road structures. Response measurements were carried out using 25-m-long 10-axle vehicles with gross weight of 90 tons. For the simulations of the responses of these test structures under the same vehicular loading, a multilayer elastic theory–based program called ERAPave was used. The required material properties for the simulations were based on laboratory testing of core-drilled samples from the sites. For the simulations, three combinations of material characterizations were considered: (a) linear elastic (LE) all layers, (b) nonlinear (NL) unbound layers, and (c) viscoelastic (VE) asphalt layers. Acceptable agreement between the simulations and measured responses were observed. Generally, the responses calculated based on LE and NL analyses were indistinguishable, whereas the VE analyses showed somewhat lower amplitude peaks.

FIELD EXPERIMENTAL STUDY ON EXTERNAL PRESTRESSING REINFORCEMENT OF A 420M PC CONTINUOUS BEAM BRIDGE

In this paper, the practical engineering of a 420 m PC continuous beam bridge is taken as the research object, and an external prestressing reinforcement method is proposed to reinforce the damaged and cracked girder. The paper is to study the structural performance of PC continuous beam bridge before and after reinforcement. The heavy vehicle loading test of reinforced PC continuous beam bridge was carried out. A total of three test spans were selected, and each test span selected seven deflection test section and a strain test section. The corresponding finite element model was established and verified by the test results. Finally, it was concluded in this study that the external prestressing reinforcement method has a good effect on improving the loading capacity and overall performance of damaged bridges.

Progressive collapse assessment of Osmangazi Suspension Bridge due to sudden hanger breakage under different loading conditions

The design life of suspension bridges can expire in a shorter time than the estimated time due to many factors such as strong winds, earthquakes, heavy tonnage vehicle loads, vehicle crashes etc. Small cracks/damages that may occur due to corrosion and fatigue effects, especially in steel elements, may increase over time and cause sudden breakages. It has been seen in the past years that hangers, which are one of the slender structural elements, can break with the tearing of the plates, especially at the hanger-deck connection points. The creation of various damage/accident scenarios during the design of these structures, which are of high importance in terms of both the country's economy and life safety, will enable quick decision-making during possible events. For this purpose, scenarios for different loading condition and different number of hanger breakage situations were created for the Osmangazi Suspension Bridge with a main span of 1550 m, which was put into service in Turkey in 2016, and progressive collapse analyses were made. The analyses, which was started by removing only one hanger, taking into account the dead load and dead load + vehicle load of the bridge, continued until the bridge collapsed. After each removed hanger, the internal force and displacement values of the hangers, cables, deck and towers of the bridge were obtained and compared with each other. The results obtained show that large force and displacement values occur in the field where the hanger is breakage, but the other parts of the bridge are not affected by this event. As the number of hangers breakage increases, the tensile strength of the hanger immediately adjacent to the hanger breakage may exceed the ultimate tensile force that the hanger can bear. This situation causes the hanger to start to break automatically and the bridge to collapse.

Dynamic Response Analysis of Buried Aviation Oil Pipeline Under Heavy Vehicle Load

The risk of damage caused by the third party construction such as vehicle rolling is increasing day by day, which seriously threatens the production and operation of the aviation oil pipeline and the life and property safety of the people along the line. Based on the theoretical calculation model of vehicle rolling, the finite element models of pipeline, soil and pipe-soil are established respectively. At the same time, the moving load is loaded using the VLOAD subroutine, and the numerical simulation is carried out using ABAQUS. Finally, the influence of vehicle rolling load on the dynamic response of buried gas pipeline under different vehicle weight and speed conditions is analyzed. The research results have important guiding value for preventing the damage accident of aviation oil pipeline caused by vehicle crushing and guaranteeing the safe and smooth operation of aviation oil pipeline.

Understanding the effects of structural factors and traffic loading on flexible pavement performance

Pavement damage increases rapidly with vehicle loads. The deterioration in pavements over time is caused by various factors but traffic loading plays a significant role in the consumption of pavement life. heavy vehicle loads, in addition to the insufficient structural capacity of pavements, are a major contributor to poor road conditions. Alligator cracking, rutting, and roughness are among the various types of distresses that are performance measures of road conditions and are the primary focus of this study. Thus, in order to improve the understanding of pavement deterioration in terms of these distresses, this paper assesses the effect of different structural factors, traffic loading and environmental conditions on pavement performance. In this study, the base type, hot mix asphalt concrete (HMAC) layer thickness, base layer thickness, traffic loading, age, and environmental conditions (precipitation and temperature) are chosen as major contributing factors for the analysis of pavement performance. Generalized linear models (GLM), binary logistic regression (BLR), and random forest (RF) approaches are employed to evaluate the data from the Long-Term Pavement Performance Program (LTPP). Cross validation technique is used to compare the efficacy of regression models (GLM, BLR) with RF. Numerous performance indicators demonstrated that RF surpasses other models in terms of accuracy and identification of influencing variables. The result from the study shows that the important design parameters that have considerable effects on rutting, roughness, and alligator cracking are the base thickness and base type. Traffic loading, pavement age and environmental factors (precipitation and temperature) are critical factors and have a significant impact on pavement performance. This study brings a new idea of using statistical methods to analyze the effects of structural factors and loading on flexible pavements.

Analysis of Plain Concrete Pavement Deflection due to Swelling on Expansive Soil

This research was conducted on the Surakarta-Gemolong-Geyer road, which is suspected to be built on expansive land. Every day, this road is always passed by large vehicles, so it is feared that it will be easily damaged if it is not routinely carried out maintenance. This study aims to analyze the damage to the rigid pavement on the highway using ATENA 3D software. The damage analyzed in this study is the deflection. The factors that make the crack large and wide were added to the heavy vehicle load and swelling. The swelling test on the soil carried out in the laboratory was 37 kPa. The results obtained after analysis with 3D ATENA showed differences in deflection at each loading variation. The variation of the middle loading with swelling pressure has a value of -15.49 mm; without swelling pressure, it is -16.37 mm. The middle loading variation with swelling and without pressure has a value of -15.33 mm and -12.4 mm, respectively. Corner loading variation with swelling and without pressure has a maximum deflection of 1.28 mm and -0.26 mm, respectively. This research can be used as a reference and prediction in identifying cracks that occur so that the government can carry out maintenance and rehabilitation before the road is damaged.

STUDY OF THE CAUSES OF ROAD DAMAGE TO CAPTAIN HARUN TOHIR STREET, GRESIK EAST JAVA

This study aims to make a study and technical planning of the road following the traffic of heavy vehicle loads through the Harun Tohir road. Road maintenance is an activity to maintain, repair, add or replace existing physical buildings so that their functions can be maintained or enhanced for a longer period. This maintenance guideline is intended to regulate the procedures for carrying out rigid pavement maintenance activities, and maintain stable serviceability conditions, to provide safety and comfort to road users. This guideline for the maintenance of rigid pavements includes descriptions of the types of damage that commonly occur in rigid pavements, their possible causes, follow-up consequences, recommendations for handling, and methods.