We analyze herein the characteristics of pavement temperature based on pavement- and atmosphere-temperature data collected from the environment-information data-acquisition system of the first full-scale test track, i.e., RIOHTrack, in China. The general rules of seasonal change and diurnal variation of RIOHTrack pavement temperature are examined for the first time. The fitting method of pavement-temperature diurnal-variation curve and pavement-temperature-variation curve with depth is studied. Considering the two dimensions of time and depth, the time- and depth-function models of pavement temperature are established, respectively. The fitting results of the measured data show that the established time-function model has high fitting accuracy for the diurnal temperature-variation curve of the pavement structure and can well fit the characteristics of asymmetric wave of the temperature curve. The depth-function model has high fitting accuracy to the change curve of pavement-structure temperature with depth and can well reflect the change law of pavement-structure temperature with depth. The analysis results and the established model can serve as a reference for the further study of pavement-temperature field and the evaluation of pavement performance.

Missing sensor data are unavoidable when sensors are used to monitor a system. These missing data largely affect the sensor applications. When missing data exist, the best method is estimation. Herein, we introduce the k-nearest neighbor on multiple-regression algorithm (KMRA), which builds on the KNN and multiple regression. In the process of estimation, KMRA considers both spatial correlations from its neighbor sensor and time correlations from its own time serials. After computing these two correlations, the algorithm combines them into a unified result of estimation. As KMRA involves spatial and time correlations, it has the efficiency and practicability as an algorithm. Examination results show that KMRA can precisely estimate the missing data.

To construct a more durable long-life asphalt pavement with semi-rigid base, we combine different technical characteristics of long-life asphalt pavements reported at home and abroad. Different interlayer bonding conditions and moduli of the bottom sublayer are considered to analyze the mechanical-state differences among long-life asphalt pavements with semi-rigid base. The following two issues are discussed:fatigue failure in the surface layer and coordination between anti-rutting and anti-fatigue characteristics. Four-point bending fatigue tests are then used at various temperatures and loading modes to evaluate the anti-fatigue characteristics of high-modulus asphalt concretes. The index of accumulative dissipated energy is adopted to compare with materials in the upper sublayer. Analysis results indicate that the application of high-modulus asphalt concrete in long-life asphalt pavement with semi-rigid base can improve anti-rutting and anti-fatigue characteristics and has some rationality.

This paper presents a method of quantifying the air-void distribution and cracking characters through X-ray computed tomography. Five mixtures are analyzed for air-void distribution, and two of them are tested for cracking development under compression. Results indicate that the meso-level air void in the five mixtures obviously differ, and the cracking-development rules are correlated on with the mixture gradation and air-void distribution. Good correlation is observed between the air-void frequency and the fractal dimension of gradation. The air-void rate on the upper part is larger than that on the bottom. Meanwhile, considering the effect of the end restraint, the cracking increment on the middle part are obviously than the upper and bottom part. The cracking in the cement-stabilized crushed stone is circular when the fine aggregate proportion is high (45%).

Asphalt materials including binder, mortar, and mixture are extensively used in the field of pavement engineering considering their obvious viscoelastic properties. To study the phase-transition temperature (T_p) of asphalt materials, we apply dynamic mechanical analysis (DMA) to conduct several temperature-sweep mode tests and compare the T_p values among these materials with similar sizes. Meanwhile, 27 AC5 mixtures are tested to determine the impact of binder type, gradation and, binder content on T_p. Results indicate that the T_p of binder and mortar is negative, but that of mixture is positive. Good correlations among T_p of binder, mortar, and mixture with the same binder type are observed, showing that binder quality is the key factor affecting T_p. Gradation type also affects T_p, and the mixture with a finer gradation has a lower T_p. Among the AC5 asphalt mixtures, the T_p of AR mixture is lower than those of the others, thereby demonstrating better low-temperature performance.

To research the compatibility and adhesion of rubber asphalt, the correlation of the asphalt components and rubber content with conventional properties of rubber asphalt was analyzed. The effects of asphalt component, rubber content, thin-film oven testing, and ultraviolet (UV)-aging testing on the adhesion properties of rubber asphalt were analyzed by measuring the surface free energy and its component based on the theory of surface free energy. Results show that the three major indicators of rubber asphalt are obviously affected by the properties of matrix asphalt, i.e., rubber asphalt has low penetration, high softening point, and movement viscosity processed by the matrix asphalt with high resin and asphaltene content. With increased rubber content, the penetration of rubber asphalt decreases and its softening point increases, but its ductility value is closer. Viscosity decreases when rubber asphalt is stored at high temperature, and viscosity decreases by 60% when stored for 8 h at 180℃. The surface energy of rubber asphalt increases with increased rubber content. After thin-film oven testing of 5, 10, and 15 h, the surface energy of rubber asphalt increases, but the change rate of surface energy decreases. The effect of UV aging on the surface properties of rubber bitumen is not obvious. The surface energies of rubber asphalt processed by different components of matrix asphalt after 10 and 20 d of UV aging differ.

Different samples of eolian sand were treated to study the sand-fixing effect of microbial-induced mineralization after mixing fly ash with eolian sand. The effects of blending fly ash on microbial-induced mineralization and sand fixation were investigated by measuring permeability, water retention, surface strength, and wind erosion resistance. After three times of microbial-induced mineralization treatment with 30% fly ash, the permeability coefficient decreased by 79.4%, the cumulative evaporation decreased by 26.5%, the surface strength increased by 19.9%, and the wind erosion rate decreased by 21.2%. The yield of calcium carbonate was negatively correlated with wind erosion rate and positively correlated with surface strength. In conclusion, mixing fly ash is more practical than simply using microbial-induced mineralization to fix sand, which can considerably reduce the permeability and improve the water retention, surface strength, and wind erosion resistance of the solidified layer of aeolian sand.

Under the influence of long time load actions, shrinkage and creep of concrete, temperature variation, and concrete pouring quality, debonding may occur between steel tube and concrete. Debonding affects the mechanism behavior of arch rib and joint and even threatens the integrity of an entire bridge. To reduce such possibility, a concrete-filled steel tubular arch bridge stiffened with perfobond ribs (PBL) is proposed. Based on a concrete-filled rectangular steel tubular truss-arch composite bridge stiffened with PBL in Xining City, Qing Hai province, we conduct force analysis of the bridge on the aspects of the arch ribs and the truss-arch composite system. According to the mechanical properties of the bridge, we establish finite-element models, including joint models in which web members bore relatively large axial force and a typical arch rib model. Based on the models, the local mechanical property of joints, and the interfacial properties between steel tube and concrete under solar radiation are studied. Results show that PBL reduces the length of force transmission and improves the stress and deformation concentration of the joints. PBL also alleviates the debonding between steel tube and concrete. This bridge scheme meets the requirements of function, aesthetics, and safety.

Considering the limitations in construction technology, deviations in the initial tension force of cables often exist. Herein, we established an analytical model through the finite-element analysis software ANSYS to study the influences of random deviations in cable tension force on the stress of pylon, beam, and cable, as well as the deformation of pylon and beam and the structural reliability of the construction of Dongguanshuidao bridge. This bridge is a composite-girder cable-stayed bridge without backstays. In our model, Monte Carlo method and Latin hypercube important sampling technique were used. Sensitivity factor and percentage of structural response were analyzed, and reliability analysis of the control-section stress was carried out. Results showed the following. First, the stress of pylon, beam, and cable, as well as the deformation of the pylon and beam, presented significant asymmetry. The related sensitivity factors had high disparities; among them, the standard deviation of stress and deformation in the side span of the beam and pylon were the least impacted by the initial cable force. Second, the initial cable force had the most influence on the final cable force of the cable, and the related number was consistent. The error level of the initial cable force was controlled according to the guidelines for the design of a highway cable-stayed bridge.

The structural health-monitoring system for a large bridge is a huge intelligent and integrated information system. Thus, conferring it with a self-checking function through a remote control is an important and difficult task. This article focuses on an integrated monitoring and management platform based on remote-control technology and proposes the overall architecture of cluster control. The platform introduces and designs the following five aspects in detail:bridge-structure network monitoring, power monitoring, system self-test equipment, mission control, and synchronization control. The research findings are applied in engineering practice, and good results are obtained.

To ensure the safety of shield tunneling near pile foundation and reduce the disturbance of this phenomenon in an urban metro in the loess area of China, a three-dimensional finite-element analysis model of shield-tunneling construction is established based on ABAQUS numerical simulation software and modified Cam-clay model. The deformation and ground settlement of adjacent-pile foundation during shield tunneling are analyzed. The law of descent is calculated and analyzed. Results show that the influence of tunnel shield on adjacent-pile foundation is primarily manifested in the X-direction displacement of the buried depth of the tunnel. During the shield-excavation process, the X-direction displacement of the pile increases gradually with decreased distance between the excavation face and the pile. When the distance between the pile axis and the excavation face of the tunnel is approximately[-0.5D, +0.5D], the displacement is the largest; when D continues to increase, the X-direction displacement is the largest. The displacement also continues to increase and eventually stabilizes. By obtaining the deformation curve of ground settlement, we find that the ground deformation is the largest above the tunnel axis and gradually decreases to both sides, whereas the pile cap is affected by uneven settlement. In the actual excavation of the tunnel project, strengthening the monitoring of the uneven settlement of the cap is necessary to take timely control measures.

To estimate traffic status on urban road accurately and determine the appropriate traffic-status evaluation interval, this research introduces a method based on the theory of set-pair analysis, and takes the number of vehicles passing the segment continuously as time interval of evaluation. First, to improve the operating efficiency of the model, based on the summary and analysis of the current research status, time interval of evaluation could be obtained according to the number of vehide passing and the instantaneous speed is taken as a single index. Second, according to the principle of set-pair analysis, set pair H (A, B)is formed by sets A (measured data) and B (standard of indices). A traffic-status evaluation model with a five-element coefficient is established from the perspectives of identity, difference, and reverse. Finally, to verify the validity of the model, we take the measured data of the eastern segments of the South Second Ring Road in Xi'an City as an example and use the fuzzy-evaluation and set-pair analysis methods to distinguish the traffic-status grade of this segment of roads. Results prove the superiority of our method. The evaluation results of the two methods are basically the same, but the traffic-condition evaluation method based on set-pair analysis theory is more sensitive to the change in speed. When evaluating road-traffic conditions, a smaller time interval means higher sensitivity of traffic conditions to changes in speed. When the evaluation time interval is less than 1 min, the result of traffic-status evaluation is no longer affected by the time interval.

In recent years, defensive driving technology has become an important research direction for road transport safety risk prevention and control. However, the research on defensive driving at home and abroad focuses on the feasibility, judgment, and recognition of defensive driving, and a quantitative research on the relationship between defensive driving training and driver emotional intelligence remains lacking. A multiple linear regression model to represent the relationship between defensive driving training and driver emotional intelligence improvement is proposed. This model is divided into two stages to describe the linear relationship between the five independent variables of driver psychology, physiology, emotion, driving intelligence, and learning time and the dependent variables of defensive driving training effectiveness. An F-test is carried out to verify the linear characteristics of the model. Results show that the average error probability of the linear impact of the five independent variables on the dependent variables is 0.047 in the two stages, which meets the requirements of multiple linear regression. The results prove that the proposed model is effective. Analysis of the model indicates that defensive driving training has two distinct characteristics on the improvement of driver emotional intelligence. In the initial stage, defensive driving training has the highest correlation with indicators related to driver agility. In the second stage, defensive driving training is highly correlated with indicators related to the psychological and emotional control of drivers.