The thermal insulating performance of ceramic asphalt concrete (CAC) is investigated based on the thermophysical parameters of asphalt mixture. CAC is produced by the replacement of the coarse aggregate in SMA-13 with ceramic aggregate by the same volume.The replacement percentages are 10%, 20%, 30%, 40%, and 50%. Thermophysical parameters (i.e., thermal conductivity, thermal diffusivity, and specific heat capacity) of the mixtures with different ceramic replacement contents are tested, and the thermal insulating effect of the CAC surface with different ceramic replacement contents on pavement is simulated. The relationship between the maximum temperature in pavement structure and the thermophysical parameters is analyzed using the gray correlation method. Results show that:(1) the addition of ceramic aggregate changes the thermophysical parameters of the mixture. Approximately 10% ceramic replacement percentage results in a reduction of thermal conductivity and thermal diffusivity by 20.5% and 23.5% respectively, and an increase of specific heat capacity by 20.9%. (2) The influence of ceramic decreases as the ceramic replacement percentage increases. FE analysis results show that, compared with the 4 cm thickness SMA-13 surface, ceramic reduces the temperature in pavement structure effectively, and 40% replacement percentage of CAC-13 significantly reduces temperature on the surface bottom by 5.2℃. Gray correlation analysis shows that three thermal parameters influence pavement temperature, and thermal conductivity has the most significant effect on temperature, followed by thermal diffusivity and specific heat capacity.

Triaxial shear experimental research is conducted on intact unsaturated aeolian soil, remolded unsaturated aeolian soil, and intact saturated aeolian soil under three different dry densities and seven different moisture contents using the true triaxial apparatus TSW-40. Moreover, the relationship between structural parameters and structural strength indexes of intact unsaturated aeolian soil is explored. Test results show a negative correlation between structural parameter ratio m_ε/m_ε0 and moisture content w but a linear positive correlation between structural parameter ratio m_ε/m_ε0 and dry density ρ_d. The functional relationships between the ratio of structural strength indexes tan φ/tan φ₀ and c/c₀ and structural parameter ratio m_ε/m_ε0 are all a quadratic function. The quantitative index or value of synthetic structural state P_cs, which reflects the effect of different factors on the structural characteristics of intact unsaturated aeolian soil synthetically, is constructed. This paper considers the strength indexes of intact aeolian soil under natural moisture contents, so that the shear strength indexes of intact unsaturated aeolian soil under discretional structural state can be calculated. This research provides a novel method for the practical use of shear strength of intact unsaturated aeolian soil for aeolian soil engineering in the west of Liaoning Province.

To address steel fiber cement concrete pavement abrasion problems, the response surface method of Design Expert 7.0 software is used to analyze the effect of aspect ratio of steel fiber, steel fiber volume adding rate, and water-cement ratio on the abrasion resistance of steel fiber reinforced concrete. Steel fiber concrete abrasion resistance model and optimization prediction model are built. Regression analysis and variance analysis are performed on the model. The model represents lack of fit at P=0.066 6>0.05, which indicates that the model's lack of fit does not show significant difference. The test data and model are irrelevant and insignificant. The multiple correlation coefficient R² is 0.986 6. The actual test difference degree is 0.013 4, and the optimization results of the solving model are unknown. When the steel fiber slenderness ratio is 56.24, the steel fiber mixing rate is 1.34%; the water-cement ratio is 0.37; and the abrasion resistance of steel fiber reinforced concrete is the optimum. The difference between the testing value and the theoretical prediction is not significant. The response theory analysis of the actual situation can be fit for steel fiber reinforced concrete abrasion surface analysis.

To understand the influence of formation methods on the performance of graded gravel,graded gravel specimens composed through two common methods, i.e., compaction and vibratory formation, were analyzed. First, the K change method was adopted to design the graded gravel; subsequently, the graded gravel specimens were generated through the aforementioned methods. The maximum dry density, optimum moisture content, and CBR values of the specimens were measured separately, and the parameters were analyzed comprehensively. The analysis of the ideal data indicated that (1) compaction formation severely disturbed the previous gradation of graded gravel, particularly the gradations from 13.2 mm to 1.18 mm; that (2) vibratory formation slightly disrupted but basically maintained the previous gradation; that (3) the CBR values of the graded gravel specimens formed through vibratory formation were almost twice as high as those generated through compaction formation; and that (4) a densely graded gravel specimen does not indicate a high CBR value.

A finite element model of a bridge that considers the nonlinear mechanical behavior of piers was built using a reinforced concrete continuous girder bridge in an expressway as the subject. Comparative analysis via nonlinear time history integration was conducted to determine the influences of frequency characteristics, peak ground acceleration (PGA), and effective duration on the magnitude and distribution of hysteretic energy and structural damage under selected typical near-fault and far-field earthquake records. The following conclusions were drawn from the result:(1)The frequency characteristics of ground motion significantly influenced the seismic response of the bridge structure, and an increase in peak ground acceleration/PGA would obviously increase hysteretic energy and damage; (2) The hysteretic energy and damage of the bridge piers under near-fault earthquakes were greater than those under far-field earthquakes at the same PGA and duration, and the position of damage was considerably higher; (3) The proportions of hysteretic energy and damage under near-fault earthquakes were less than those under far-field earthquakes in certain regions near the pier bottom, whereas the aforementioned indices were contrary outside that region; this finding showed that hysteretic energy and damage under near-fault earthquakes were well-distributed along the piers. The comparative analysis indicated that near-fault earthquakes had higher energy and damage dissipation requirements than far-field earthquakes, and that such requirements increased upward along the pier. Consequently, strict measures for the seismic design of bridges under this type of earthquake should be proposed.

A novel high-damped rubber bearing was applied to a continuous girder bridge. The flexuary capacity of piers and piles and the displacement demand of bearing were used as research objects. Simulation was performed by using a numerical model of the seismic isolation performance along the longitudinal direction of an irregular concrete continuous girder bridge. Various parameters and isolator layouts were optimized on the basis of FEM results to regularize and unify the seismic demands of the entire system. An unseating prevention device and a restrainer were used along the longitudinal direction to reduce the seismic displacement of the isolated girders. The design scheme of the pile foundation was also discussed. The effects of soil stiffness, nonlinearity of bearings, and collision of restrainer blocks were included in this analytical course. Numerical results reveal the excellent isolation performance of high-damped rubber bearings.

Bridge load test, especially static test evaluation, is one of the most commonly utilized bridge inspection appraisal methods. Verification coefficient values are rough and could not adapt to the trend of bridge construction over the years. To improve calculation precision and evaluation accuracy, a concept of verification coefficient of the impact factor is proposed. A new verification coefficient calculation method based on the analysis of the differences between the calculation model and actual structure and combined with the characteristics of practice and calculation modeling error is presented. Then, a theoretical verification coefficient calculation method is established, and the range of verification coefficient values of different parameters is summarized. After calculating the deviation percentage, research is conducted to reduce bridge assessment misjudgment. A practical optimization method for bridge static test evaluation is established. This optimization method comprises three parts, namely, correction calculation of the theoretical value, optimization analysis of the verify coefficient range, and evaluation algorithm for the deviation percentage. Numerical examples show that the proposed optimization method can reduce the deviation percentage and improve the accuracy of evaluation results. The method is suitable for all bridge inspection applications.

To improve the traditional fuzzy evaluation method and reflect its nonlinear characteristics, a nonlinear fuzzy evaluation method based on the entropy weight of a structure is proposed according to the construction risk characteristics of the integral hoisting of concrete-filled steel tube (CFST) tied-arch bridge. The risk sources in the construction process of the integral hoisting of CFST tied-arch bridge are associated with structural and personnel safety are considered, and a construction risk level evaluation system is established. A two-level fuzzy evaluation calculation model of the said bridge is established based on the identified results. The the entropy weight of a structure method, which combines the subjective and objective assignment methods, is adopted to calculate the weights of risks. A nonlinear fuzzy algorithm is introduced to reflect the prominent effect of high-risk indicators on the evaluation results. The nonlinear fuzzy evaluation method for the construction risks in a tied-arch integral hoisting of CFST tied-arch bridges is then established. An analysis of an engineering example proves that this method is feasible and effective.

Blasting load is investigated using LS-DYNA software for the tunnel structure with different densities of expanded polystyrene (EPS) granule layers. Analysis of different points of pressure shows that the presence of EPS granule layers has beneficial effects on the attenuationof the stress wave, and the pressure decay exponent increases with the increase in particle density. In addition, the presence of EPS granule layers can reduce the tensile stress caused by the impact of the free surface of the tunnel. A mathematical model of the pressure attenuation index relative to EPS grain density and relative distance is established.

To reduce the negative effects of intersection delay caused by bus priority signal control, three types of bus priority green loss equilibrium methods were proposed, namely, green extension, red truncation, and prior phase insertion. Given the process of vehicle accumulation, evacuation, and parking start-up at intersection imports, a model for delay calculation under green loss equilibrium was established. This model was developed by increasing or decreasing the calculation caused by length variation on the left and right ends of the green phase. A delay overlay analysis was also applied. A bus priority optimal signal-planning model based on green loss equilibrium for maximizing the reduction of total average delay at intersections was presented to optimize the parameters. Green loss equilibrium is subject to the status of the vehicles at rest, which may normally move. A method for solving the function was designed by utilizing the diagonalization algorithm, which is based on the Frank-Wolfe algorithm. Results showed that the new delay calculation model can describe the delay change at bus priority intersections more precisely compared with existing methods. The optimal signal-planning model showed effective green loss equilibrium results with non-priority phases. The amount of delay reduction at intersection was also significant.

Different grades of roads have different function goals during the process of planning and design. The extent of function realization has significant effects on the operational efficiency of a road network system. In accordance with the function description of urban expressways in the Code for Design of Urban Road Engineering (CJJ37-2012), this study presents the concept of urban expressway functional reliability. This concept is also considered as a quantitative and probability evaluation index of the achievement degree of expressway functions. The calculation method of expressway functional reliability is constructed by combining vehicle speed with the coefficient of headway variation. The similarities and differences between the level of service and the proposed function reliability are discussed. Three expressway sections in Zhengzhou city are taken as case studies. The independence between vehicle speed and headway variation coefficient is verified based on the real data collected through video. Functional reliability evaluation results agree well with the results from the service level analysis, which proves the feasibility and applicability of the proposed method.

Average travel speed and density ratio are selected as the traffic state evaluation indexes. Based on the long-term analysis of the distribution characteristics of the detection data of 166 intermodulation points of 26 national and provincial highways in Chongqing, the model for calculating the point speed and travel speed during congestion is established, and the reasonable rating thresholds for identifying indicators are determined according to the grade test scores. Based on logical rules, the synthetic evaluation model that uses travel speed and density ratio as evaluation indexes is established, and the evaluation method suitable for ordinary highway operation status in China is determined. By verifying and analyzing the determination result of the actual operation status of the 26 common highways in Chongqing, the better adaptability of the model is proven.

A valid path searching method was applied in an interrupted urban rail transit network line to determine a rapid, accurate, and easy path for evacuating stranded passengers. The method is based on the established urban rail transit network model and considers the characteristics of interrupted rail networks. Valid paths were redefined with constraint conditions, such as fault points, maximum transfer times, and generalized cost. The depth-first algorithm was also improved, and the valid path searching model for interrupted urban rail transit network lines was established. The model was validated in Shanghai Metro Network, an interrupted urban rail transit, by using the C# programming language. Results show that when People Square station is interrupted, five valid paths can be searched between Shanghai West Railway station and Pudong International Airport station with constraints.

The establishment of a waiting area in an intersection with a complex traffic flow is investigated. With the adoption of the basic conditions of a waiting area, capacity and delay models are established to examine the differences in the capacities of and delays in an intersection with and without a waiting area. Signal control parameters, such as green light interval time and effective green-light time, are also studied. The increase in capacity and reduction in delay from the setting of a waiting area are deduced by using accurate mathematical equations. With the use of actual intersections as examples, traffic operation efficiency was analyzed through simulation. Simulation results can be summarized as follows:generally, under high flow rate and saturation conditions, setting a straight waiting area can adequately utilize the intersection spare space, improve usage efficiency of straight lanes, and maximally realize reciprocal transformation between time and space. Consequently, the capacity of straight lanes is improved, the delay per vehicle is reduced, the capacity of the intersection is enhanced to some extent, and the delay in the entire intersection is reduced, thereby verifying the validity and applicability of the model.

Risk and cost are the basic characteristics of the road transportation of dangerous goods. The characteristics in the programming of the road transportation network of dangerous goods were considered in this study. The influencing factors were divided into seven parts, namely, transportation distance, accident possibility, on-road population exposure, off-road population exposure, property damage, environmental pollution, and efficiency of emergency response. These factors were quantitatively evaluated by using the analytic hierarchy process. The relative weight was calculated. A bi-level model of the road transportation network of dangerous goods was formulated with the minimum risk that governments demand as the upper objective function and the minimum cost that enterprises demand as the lower objective function. The model was calculated by using the genetic algorithm (GA). The case study indicated that solving the bi-level programming model by using GA could rapidly identify a route that meets the minimum risk and cost simultaneously in the road transportation network of dangerous goods, complete the synthetical optimization of the road transportation network of dangerous goods, and find the optimal point of balance between risk and cost.

We constructed the evaluation index system of the transport scheme based on the influencing factors of large-scale highway transport to save cost and improve the decision-making process of a large-scale transport scheme. The scheme considered safety, technical, economic, and timeliness factors. Moreover, we used the analytic hierarchy process (AHP)-grey correlation degree method to optimize the transport scheme. The method adopted AHP to determine index weight, used benefit and cost index normalization to change the decision-making matrix into a relative membership degree matrix, and chose the scheme according to grey correlation degree between the best scheme and alternatives. The methods provided an effective solution for multi-index quantitative analysis of the transport scheme. The objectivity and effectiveness of the method was validated using an example.

This study analyzes the difficulties faced by road development policy in China, and evaluates the toll-road policy from a historical perspective. On the basis of experiences of foreign countries, the study examines the theoretical foundation and decision factors from the standpoint of goods supply theory and Maslow's hierarchy of needs, as well as points out the strategic direction of policy adjustment for road development in China. Finally, the paper proposes that the country's road-development policy adjustment should be based on reality and national conditions. The new policy should be just and efficient as well as promote freeway financing ability and public investment in toll-free roads to provide the public a fair and equal toll-free road system with high quality and efficiency.