Heavy Vehicle Loads Research Articles

Design of Main Bridge of Second Penang Bridge in Malaysia

The main bridge of the Second Penang Bridge in Malaysia [1-2] is a two-pylon three-span prestressed concrete cable-stayed bridge, with span arrangement of (117.5+240+117.5) m.The pylons and the main girder are monolithic. The main girder, which is 34.6m wide, adopts the ladder type concrete deck section comprising top slab, transverse diaphragms and edge beams. The pylons are H-form pylons, and the stay cables are formed of parallel strands and are arranged in fan cable planes. Each pylon column carries 18 pairs of stay cables that are anchored by the deviation saddles in the pylons and anchor blisters in the main girder. The foundations consist of large diameter bored piles, varying from 2.3m to 2.0m in diameter. An optimized design scheme is tailored for the bridge, in which the main girder has the cross-section built up by a combination of slab, diaphragm and edge beam structuresand was constructed by using the rear supported form traveler and incorporating an optimization of construction timing. The scheme resolved the problems of load-bearing capacity verification for bridge deck and the verification of main girder prestress under the heavy vehicle loads prescribed in the BS5400. Meanwhile, a meticulous calculation method was put forward for the design and analysis of the main girder, to obtain the real load bearing conditions of the main girder and the bridge deck. The diaphragms were calculated by the spatial grillage analysis method, aimed at guaranteeing the load-bearing safety of the structure.

Traffic characteristics and bridge loading in South Africa

The loading model of the Technical Manual for Highways (TMH-7) published for bridge design in South Africa is in need of revision and simplification. The frequency of heavy vehicle loads has increased and the current application of the loading model is unnecessarily cumbersome. This paper aims to compare the heavy vehicle traffic loading of South Africa and Europe. A comparison of global internal bridge forces under the NA loading of TMH-7 and LM1 loading of Eurocode provides an indication of how current South African provision relates to the ones adopted in Europe. Above all, the traffic characteristics in South Africa are investigated in comparison to data used in development of LM1. LM1 loading generally results in higher internal forces when compared to TMH-7 loading. A direct adoption would thus imply more expensive bridges across South Africa without substantiation, considering the satisfactory past performance of existing structures. More importantly, the gross vehicle weights observed in South Africa are higher than those used for the development of LM1, indicating that the current TMH-7 distributed loading may be too low. Axle loads and their variability in South Africa are somewhat less than in Europe, so local design effects are less of a concern. It is apparent that further urgent work is required to establish a load model that reflects the current heavy vehicle traffic and predicts appropriate characteristic vertical loads.

Sensitivity analysis of the mainline travel lane pavement service life when utilizing part-time shoulder use with full depth paved shoulders

Part-time Shoulder Use (PTSU) is an Active Traffic Management (ATM) strategy that utilizes the shoulder as an additional travel lane during high congestion periods to temporarily increase roadway capacity. This strategy has become increasingly popular on freeways around major metropolitan areas in the United States (U.S.) and Europe. This research focused on freeways near major metropolitan areas where the roadways are structurally sound, but widening roadways has become increasingly expensive to implement. These areas typically utilize full-depth paved shoulders, defined as shoulders built to the same pavement structural profile as the mainline travel lanes and structurally sufficient to carry heavy vehicle loading. As a result of PTSU, the load repetitions on the mainline travel lanes can be reduced for multiple hours during each day by shifting vehicles to the shoulder and this load reduction may indirectly increase the mainline pavement’s service life. This research explored the potential benefits of PTSU based on a variety of conditions, including climate conditions, pavement types, and traffic loading levels. The results suggest that across all of these conditions an extension of 10–20% in service life can be expected for both flexible and rigid pavements in the mainline travel lanes.

Assessment of cracks detection in pavement by a distributed fiber optic sensing technology

This paper presents the feasibility of damage detection in asphalt pavements by embedded fiber optics as a new non-destructive inspection technique. The distributed fiber optic sensing technology based on the Rayleigh scattering was used in this study. The main advantage of this technique is that it allows to measure strains over a long length of fiber optic with a high spatial resolution, less than 1 cm. By comparing strain profiles measured at different times, an attempt was made to link strain changes with the appearance of damage (cracking) in the pavement. This non-destructive method was evaluated on accelerated pavement testing facility, in a bituminous pavement. In our experimentation, the optical fibers were placed near the bottom of the asphalt layer. The application of 728,000 heavy vehicle loads (65 kN dual wheel loads) was simulated in the experiment. Optical fiber measurements were made at regular intervals and surface cracking of the pavement was surveyed. After some traffic, a significant increase of strains was detected by the optical fibers at different points in the pavement structure, before any damage was visible. Later, cracking developed in the zones where the strain profiles were modified, thus indicating a clear relationship between the increased strains and crack initiation. These first tests demonstrate that distributed fiber optic sensors based on Rayleigh scattering can be used to detect crack initiation and propagation in pavements, by monitoring strain profiles in the bituminous layers.

Research on identification method of heavy vehicle rollover based on hidden Markov model

AbstractAiming at the problem of early warning credibility degradation as the heavy vehicle load and its center of gravity change greatly; the heavy vehicle rollover state identification method based on the Hidden Markov Model (HMM, is introduced to identify heavy vehicle lateral conditions dynamically in this paper. In this method, the lateral acceleration and roll angle are taken as the observation values of the model base. The Viterbi algorithm is used to predict the state sequence with the highest probability in the observed sequence, and the Markov prediction algorithm is adopted to calculate the state transition law and to predict the state of the vehicle in a certain period of time in the future. According to combination conditions of Double lane change and steering, applying Trucksim and Matlab trained hidden Markov model, the model is applied to the online identification of heavy vehicle rollover states. The identification results show that the model can accurately and efficiently identify the vehicle rollover state, and has good applicability. This study provides a novel method and a general strategy for active safety early warning and control of vehicles, which has reference significance for the application of the Hidden Markov theory in collision, rear-end and lane departure warning system.

Cause Analysis of Asphalt Pavement Rutting on Section N5 in Pakistan

It was well known that rutting is one of the most common types of pavement distress for asphalt pavement under heavy vehicle loading in hot climate. In this study, the cause of rutting on highway N5 in Pakistan was reviewed in detail, mainly including climate conditions, pavement materials and traffic control. It was concluded that local conditions should be carefully considered for projects either designed or constructed by Chinese companies during the implementation of ‘One Belt, One Road’ strategy.

EFFECT OF ROAD SURFACE DEFORMATIONS ON LATERAL LANE UTILIZATION AND LONGITUDINAL DRIVING BEHAVIOURS

Various road surface deformations generally occur on urban and rural roads due to infrastructure, superstructure deficiencies and excessive heavy vehicle loads. In addition to driver-based errors, many accidents happen due to these mentioned surface deformations. This study aims to present lateral lane utilization and longitudinal driving behaviours on a two-lane deformed road. The effect of deformation on the tendency of drivers’ lane selection, lane utilization, and the movement in traffic flow will also be determined. For this purpose, parameters such as lateral position, speed, acceleration/deceleration and location data of vehicles travelling through four different deformation zones on a two-lane road in Izmir (Turkey), were collected. Based on the fact that in ideal conditions, distribution of lateral positions of vehicles in a lane is similar to normal distribution. The collected data was evaluated with chi-square (χ2) goodness of fit test to see if they are fit to normal distribution or not. This study concluded that if a deformation zone has wider area and less depth, it will be less effective on lateral lane utilization of vehicles. It was also obtained from the results that variation in other parameters such as deformation type, depth and height are associated with the lateral lane utilization of drivers. Additionally, the drivers’ characteristics such as perception and aggressiveness are seen as the most important factors influencing the longitudinal vehicle behaviours while passing through the deformation zones.

Cost Impact of Increasing Heavy Vehicle Loads on Bridges

This study aimed to investigate the cost impact of meeting the increase in freight demand by doubling the truck weight (AS1), doubling the traffic volume (AS2), or legalizing a new-proposed-truck of 97-kip weight instead of the currently legal 80-kip truck (AS3). The State of Michigan's average daily traffic database of year 2001 has been used as a case study. The study was applied only on the very common US Bridge with RC (reinforced concrete) deck over steel girder. Sampling criteria also includes the age of the bridges. The study covered the four-cost-impact categories provided by the NCHRP (National Cooperative Research Program). The current truck weight and double traffic volume (AS2) show the best scenario to meet the increase in freight demand. However, doubling the truck weight with the current traffic volume (AS1) was the worst scenario. The use of the proposed 97-kip truck with the current traffic volume (AS3) compromises both, meeting the increase in freight demand and the cost impact.

Multiscale testing-analysis of asphaltic materials considering viscoelastic and viscoplastic deformation

Fine aggregate matrix (FAM) is a phase consisting of asphalt binder, air voids, fine aggregates and fillers. It acts as a primary phase in evaluating the damage and deformation of entire asphalt concrete mixtures. The simplicity, repeatability and efficiency of the FAM testing make it a very attractive specification-type approach for evaluating the performance characteristics of the entire asphalt concrete mixtures. This study explores a linkage in the deformation characteristics between the two length scales: asphalt concrete mixture scale and its corresponding FAM scale. To that end, a simple creep-recovery test was conducted for both mixtures (i.e. asphalt concrete mixture and its corresponding FAM phase) at various stress levels. Test results were compared and analysed using Schapery’s single-integral viscoelastic theory and Perzyna-type viscoplasticity with a generalised Drucker–Prager yield surface. In particular, stress-dependent nonlinear viscoelastic and viscoplastic behaviours were characterised in addition to linear viscoelastic deformation characteristics, because the nonlinear viscoelastic and viscoplastic behaviours are considered significant in asphalt pavements that are subjected to heavy vehicle loads and elevated service temperatures. With a limited scope and test-analysis results at this stage, it was found that there is a strong link between the FAM and asphalt concrete in (linear and nonlinear) viscoelastic and viscoplastic deformation characteristics. This implies that the viscoelastic stiffness characteristics and viscoplastic hardening of typical asphalt concrete mixtures could be estimated or predicted from the simple FAM-based testing-analysis method, which can significantly reduce the experimental–analytical efforts required for asphalt concrete mixtures.

Sparsel1optimization-based identification approach for the distribution of moving heavy vehicle loads on cable-stayed bridges

A method for identifying the distribution of moving heavy vehicle loads is proposed for cable-stayed bridges based on a sparse l1 optimization technique. This method is inspired by the recently developed compressive sensing (CS) theory, which is a technique for obtaining sparse signal representations for underdetermined linear measurement equations. In this study, sparse l1 optimization is employed to localize the moving heavy vehicle loads of cable-stayed bridges through cable force measurements. First, a simplified equivalent load of vehicles on cable-stayed bridges is presented. Then, the relationship between the cable forces and the moving heavy vehicle loads is established based on the influence lines. With the hypothesis of a sparse distribution of vehicle loads on the bridge deck (which is practical for long-span bridges), moving heavy vehicle loads are identified by minimizing the ‘l2-norm'of the difference between the observed and simulated cable forces caused by the moving vehicles penalized by the ‘l1-norm’ of the moving heavy vehicle load vector. A numerical example of an actual cable-stayed bridge is employed to verify the proposed method. The robustness and accuracy of this identification approach (with measurement noise for multi-vehicle spatial localization) are validated. Copyright © 2015 John Wiley & Sons, Ltd.

Relationship between Traffic Loading and Environmental Factors and Low-Volume Road Deterioration

Many countries use some form of model to determine road user charges. Trucks are expected to pay for most of the cost because heavy vehicles are responsible for most of the deterioration of roads. This research documents findings that will ultimately be used to refine the New Zealand road user charge models. The research was undertaken on data from the Long-Term Pavement Performance Program with the specific aim of determining the relative damage caused by heavy-vehicle loading alone compared with the combined effects of loading and environmental impacts. As part of the overall research process, a cluster analysis was undertaken. The results from this analysis also emphasized the importance of drainage. The cluster analysis resulted in a recommended stratification of low-volume roads on the basis of their urban or rural location, traffic loading, and climatic area. This stratification could be used for a more detailed implementation of a user charge model if needed. On similar low-volume roads, an approximate 0.1-mm/year higher rut rate was observed in areas that had a wetter climate in combination with sensitive in situ soil conditions. The results also illustrated that adequate drainage was vital for limiting environmental impacts. Roads with inadequate drainage had a rut rate 2.5 times as high as that of roads with the necessary provision for drainage.

Structural evaluation of a GFRP truss girder for a deployable bridge

Lightweight for transport facility and reduced assembling and erection time are the main requirements to deployable bridges for emergency purposes which can be easily satisfied by using GFRP profiles. A reduced scale model of the truss girder component of a thirty meters span bridge has been tested in laboratory. The prototype bridge is composed of a GFRP grid floor deck supported by prestressed truss girders which are mounted by assembling GFRP tubular profiles and steel joints with bearing type connections. Structural tests first focused on the behavior of a 13m span simply supported truss girder model fabricated in the reduced geometric scale 1:2.3. This paper presents the description and the results obtained from numerical modeling and from experimental tests performed on the truss girder assembled with three distinct connection details between GFRP tubes and steel joints. The experimental results showed that improved performance of the connections make the proposed conceptual design plainly appropriate to be used as truss girders of a new concept of composite deployable bridge that can carry heavy vehicle loading.

Response of Perpetual Pavement under Different Axle Heavy Truck

To investigate suitability of the perpetual pavement under ultra-heavy loads, a test road was constructed on expressway in Shandong province of China. There were five pavement structures include semi-rigid asphalt pavement, each was instrumented with gages for measuring the strains of asphalt base layer, the vertical stress of subgrade, temperature of asphalt layers. The analysis of the strain data indicated that the strain values are affected by the temperature, the vehicle load, axle type, and the pavement structure combination. To research the response of different structure, tested different axle and load at different temperature, then different pavement response models were developed that accounts for layer thickness, axles load, pavement temperature and equivalent modulus of pavement foundation. The models provides good references under heavy vehicle loading and China local climate, it will be useful for perpetual pavement design.

RESEARCH AND EVALUATION OF RUTS IN THE ASPHALT PAVEMENT ON LITHUANIAN HIGHWAYS

When exposed to destructive climate and weather factors and heavy vehicle loads, the pavement wears and deflects. In recent decades, apart from cracks and potholes, the depth of ruts grows and makes an increasing share of the pavement surface. The deeper are the tracks, the poorer are traffic conditions for fast-moving cars: drivers are struggling, speed is decreasing and the number of accidents is increasing. After track depth reaches a critical and permissible limit, the road surface must be repaired or speed limit has to be reduced. The work presents a theoretical analysis of track emergence causes and factors determining their depth. With the help of Mobile Road Research Laboratory RST 28, the track depth of all Lithuanian highways has been measured every 20 metres. The obtained data have been processed using the methods of mathematical statistics. Each road has a sample average of every rut, sample standard deviation and a coefficient of individually measured variation. The paper has drawn histograms, calculated skewness, kurtosis and normal distribution and provided lognormal distribution curves of a probability density function. The visualisation and empirical skewness and kurtosis values have revealed that the depth of the rut distributes according to lognormal rather than normal distribution. The average values of the roads having a dividing strip and standard deviations from the distribution across the road have been received. The given dependence of the rut depth of a standard deviation on the averages of rut depth shows an elastic interface of these parameters (determination coefficient R2= 0.741).

Responses and Performance of Stabilized Full-Depth Reclaimed Pavements at the Minnesota Road Research Facility

This paper details the construction and analysis of three stabilized full-depth reclamation (SFDR) sections (Cells 2, 3, and 4) constructed at the Minnesota Road Research Facility on I-94 in 2008. Three test sections with different ratios of pulverized asphalt concrete to granular base were constructed, and the performance of full-depth reclaimed pavements stabilized with engineered emulsion was studied. Emulsion content and base structure varied between test sections. Each test section was designed for 3.5 million equivalent single-axle loads for a period of 5 years. As of June 30, 2012, the sections had been subjected to approximately 2.2 million such loads. Responses were measured with strain gauges embedded at the bottom of the hot-mix asphalt and SFDR layers in each test section. The strain gauges indicated that the bottom of both the hot-mix asphalt and the SFDR layers was subject to horizontal tensile strain from falling weight deflectometer testing and heavy vehicle loading. Pavement performance for rutting, cracking, and international roughness index was measured periodically. The results indicated that all three cells were performing well. The only crack in the three cells was in Cell 3; the roughness index values were well within the acceptable range and rutting, although progressing, was still acceptable. The paper concludes with modeled responses and performance predictions from DARWinME and BISAR. Model predictions indicate that an SFDR layer will provide greater structural benefits and increased performance than will similar structures with unstabilized full-depth reclaimed or granular base layers.

An Experimental Study on a Culvert Buried in Granular Soil Subjected to Vehicle Loads

To understand the performance of culverts buried in the granular soil under heavy vehicle loads, both experimental and numerical studies are conducted. Full-scale model tests with tire loads applied at different locations are carried out to obtain experimental data, and numerical simulation using 3D finite element method is performed to predict the culvert responses and soil distribution due to the same load distribution. Comparisons of the model test results with the computed responses are made in terms of soil pressure above the culvert crown, culvert structure's strain, and culvert deflection. The model test results indicate that the buried concrete culverts embedded with compacted aggregate perform good behavior without structural distress. Both numerical analyses and model tests show that the vehicle loads transferred to culvert crown decrease rapidly with the thickness of fill over the culvert. Based on the model tests and numerical analyses, the cover depth of 1.0 m at least is suggested for prefabricated concrete culverts.

Dynamic Analysis of Sandwiched Composite Foldable Structure under Heavy Vehicle Load

Foldable structures are very important for the purpose of rapid construction and bridging system. Such structural element can be utilized in disaster relief operations. In the early days, portable structure such as military bridges were made from steel, causing the weight of the structure to be huge, subsequently it will be costly to operate. To overcome these problems, aluminium and metal alloy were introduced to reduce the weight of such structure. Use of composite material such as Carbon Fiber Reinforced Polymer (CFRP) emerges as a lighter alternative being considered to be the primary material for the portable structure. The use of the CFRP as a primary material is due to its high strength to weight ratio, thus make it lighter than steel and other alloy. In this research, a long-span portable structure is analysed and designed using finite element method. Several dynamic simulations are made to test various possible lay-up including use of core in order to increase strength and stiffness of the member. From the trials it can be concluded that with proper design and fabrication, CFRP is capable of carrying the designed dynamic load. Furthermore, use of core layers for top flange can improve the performance of the structure significantly, while use of core to the webs stiffen the webs against buckling and further improve the overall performance of the structure.

Research of Steel Deck Pavement Suitable Paving Materials

This study utilized mechanical calculation method and finite element method ABAQUS software to analyze the mechanical response of different flexible pavement material combinations on steel deck. Heavy vehicle load with high axle load and high tire pressure were considered, so as to know the reasons for steel deck pavement distress, and to define the arrangement principle for steel deck pavement and the combination of materials suitable for flexible pavement. The results show that the fatigue damage of steel deck pavement coincides with traditional theory, the maximum tensile strain at the bottom of surface course is still the determination index, and the fatigue crack is presented mainly in four types; the maximum compressive strain on the top of steel plate is the determination index of rutting damage, the major cause for rut is the surface course under compressive strain in the wheel load position. The suitable material for steel deck one-course pavement is full depth Guss asphalt mix; the suitable combination for steel deck two-course pavement is modified asphalt mix on top and Guss asphalt mix at bottom.

Field Study of Overload Behavior of an Existing Reinforced Concrete Bridge under Simulated Vehicle Loads

Overload attributable to increased vehicle loads is becoming an increasingly serious issue in highway transportation. Overload results in damages to bridge structures, degradation of their load-carrying capacities, and even collapse of bridges, which may cause loss of lives and properties. Hence, the actual load-carrying capacity of existing bridges with many years of service and obvious damages is becom- ing an important concern for researchers and engineers. In this paper, field experiments were conducted on a simply supported concrete girder bridge located at Province Road 209 of Hunan Province, China. Test loads were applied to the bridge through a group of hydraulic jacks to simulate the heavy vehicle loads of 196 and 294 kN on single-lane loaded and two-lane loaded cases. The results showed that at the deflection limit, the measured load-carrying capacity of the tested bridge was much higher than the designed value. During experiments, the transverse connection stiffness of the bridge varied insignificantly. Cumulative damage of the structure was observed when the simulated cyclic loads were increased to three times the weight of the 294 kN truck on a two-lane loaded case. DOI: 10.1061/(ASCE)BE.1943-5592.0000140. © 2011 American Society of Civil Engineers. CE Database subject headings: Reinforced concrete; Bridges, concrete; Overloads; Vehicles; Cyclic load; Simulation. Author keywords: Reinforced concrete bridge; Overload behavior; Vehicle load; Existing bridge; Cyclic load.

The use of neural network to predict the behavior of small plastic pipes embedded in reinforced sand and surface settlement under repeated load

This paper presents a feed forward back-propagation neural network model to estimate the vertical deformation of high-density polyethylene (HDPE) small diameter flexible pipes buried in reinforced trenches and settlement of soil surface (SSS) subjected to repeated loadings to simulate the heavy vehicle loads. The experimental data show that the vertical diametral strain (VDS) of pipe embedded in reinforced sand and SSS are dependent on relative density of the sand, number of reinforced layers and height of embedment depth of pipe. Therefore in this investigation, the value of VDS and SSS are related to the above parameters. In the developed neural network, the neurons of the input layer represent the relative density of the sand, number of reinforced layers and height of embedment depth of pipe. One neuron is used in the output layer to represent the value of VDS or SSS. In the entire test, the intensity of applied repeated loads is constant (5.5 kg/cm 2, equal to maximum traffic load). A database of 72 experiments from laboratory tests were utilized to train, validate and test the developed neural network. The results show that predictions of VDS and SSS using the trained neural network are in good agreement with experimental results. A comparative evaluation of artificial neural network (ANN) and regression model show that the predictions obtained from the neural network are better than regression model compared to those obtained with the experimental results.