通讯机构：
[Wen, W ] C;Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Peoples R China.
关键词：
Disintegrated carbonaceous mudstone;Triaxial test;Numerical simulation;Discrete element method
摘要：
The paper aims to study the mechanical characteristics of disintegrated carbonaceous mudstone in a triaxial stress state from a micro-perspective of particles. Based on the discrete element method (DEM), a spherical-polymer (SP) model that includes three different types of the particles (triangle-like, rectangle-like, and sphere) was proposed and combined the error diagram with R2 to analyze the difference between the SP model and Ball-Ball (BB) model. Meanwhile, a sensitive analysis of micro-mechanical characteristics was carried out, which quantitatively described the sensitivity of different parameters according to stress-strain curves. The processes of deformation and failure for the disintegrated carbonaceous mudstone were finally analyzed based on the displacement diagram of the particle according to the energy theory. The results suggest that the SP model could better reflect the mechanical characteristics of disintegrated carbonaceous mudstone, for the SP models, the correlation coefficient (R2) range was larger than the BB model. From the sensitivity analysis of parameters, the decreasing rate of initial deformation modulus was 56-66% as the stiffness ratio was modified when fixing other factors. The peak strength correlated well with the tensile-shear strength ratio, stiffness ratio, and friction coefficient. The modification of abnormal-shaped particles' volume fraction ratio could affect the peak shear strength significantly. For the disintegrated carbonaceous mudstone, the processes of deformation and failure were discussed by energy transference which particle elements go from a low-energy state to a high-energy state.
关键词：
Asphalt;Dry flue gas desulfurization ash;Filler;Rheological properties;Pavement performance;Leaching
摘要：
This study aims to explore the feasibility of using dry flue gas desulphurization ash (DFGDA) as a filler in asphalt pavements. Two DFGDA materials were added into the base asphalt with different mineral powder proportions to prepare asphalt mastic and mixture, and the pure mineral powder asphalt mastic and mixture were used as the blank control group to evaluate the properties of DFGDA-doped asphalt mastic and mixture. The results show that the addition of DFGDA can improve the high-temperature rheological property and reduce the low-temperature rheological property of asphalt mastic; similarly, the high-temperature stability of asphalt mixture can be greatly improved, while its low-temperature performance and water stability are reduced; despite these decreases, all outcomes still meet the requirements of relevant specifications. No chemical reactions are observed between DFGDA and asphalt, indicating that the physicochemical properties of fillers are responsible for the change in the properties of DFGDA-doped slurry and mixture. Notably, the DFGDA-added asphalt mixture does not bring additional negative effects to the environment. Based on cost analysis, the high-quality use of DFGDA in asphalt mixture can save direct material costs of about $920,000 per 100 kilometers of asphalt road construction. In summary, the application of DFGDA in the asphalt mixture can not only meet the basic performance requirements of asphalt pavements but also greatly save material costs and protect the environment.
摘要：
Asphalt pavement, a major type of road surface, may contain hazardous elements depending on its specific composition. A growing concern has developed regarding the potential leaching of these hazardous constituents from asphalt pavements, particularly when incorporating waste materials and additives. This study investigates the presence of heavy metals and polycyclic aromatic hydrocarbons (PAHs) in leachates from six commonly employed asphalt paving materials. A comprehensive laboratory leaching experiment was conducted on three key sample scales: asphalt binder, asphalt mortar, and asphalt mixture. The impact of the leachates was assessed by the heavy metal pollution index and the toxic equivalency factor based on the benzo[a]pyrene equivalent concentration. The results reveal that leaching tests at the binder and mortar scales provided fundamental insights into leaching characteristics within a relatively short timeframe, while the mixture-scale test was more capable of representing pollutant leaching in near-true scenarios. In addition, the results indicate potential adverse health implications associated with the incorporation of hazardous waste, such as bottom ash, into asphalt pavement. These findings hold significant implications for promoting environmentally responsible practices of asphalt pavement.
摘要：
The copula dependence structure underlying the correlated shear strength parameters of soils can significantly affect the results of slope reliability analysis and risk assessment of slope failure. Currently, how do copula dependence structures affect the failure modes of slopes in spatially variable soils still remains an open question. This study systematically investigates the effect of copula dependence structures on the failure modes of a cohesive-frictional slope in spatially variable soils via an adapted random finite difference method (RFDM) that incorporates the copula-based random fields. The proposed RFDM proceeds with the simulation of cross-correlated random fields considering the copula dependence between the shear strength parameters of the slope. The strength reduction analyses are then performed within the framework of Monte Carlo simulation to obtain the stability analysis results, including the critical slip surface (CSS) and associated factor of safety (FS) and sliding volume. Finally, various statistical analyses on the number and distribution of CSS, FS and sliding volume as well as the failure modes versus different statistics of soil properties are analyzed considering different dependence structures. The results show that the overall distribution range of CSS obtained by the commonly used Gaussian copula is more concentrated, whereas the result by the No. 16 copula is the widest. The differences in the overall distribution range of CSS among different copulas decrease with the increase of the scale of fluctuation, coefficient of variation, and cross-correlation coefficient of the strength parameters. The proportions of different failure modes are comparable for the Gaussian, Plackett and Fran copulas, whereas the No.16 copula has the smallest proportion for the shallow failure and largest proportions for the deep and multi-slip failures. The influence of copula dependence structure on the slope failure mode is more significant than the statistical parameters of soil properties. The results provide useful references for copula selection when the underlying dependence structure is difficult to be determined.
摘要：
The compatibility of cold-mixed epoxy asphalt (CEA) significantly influences its mechanical properties, primarily mediated by the epoxy group content within CEA. However, the feasibility and mechanisms for regulating the external epoxy group content to achieve optimal performance have yet to be explored thoroughly. Herein, soybean oil, epoxidized soybean oil, and epoxy-terminated hyperbranched epoxy resin (EHER) were used to construct CEA with different external epoxy group contents, and their effects and mechanisms on the compatibility and mechanical properties of CEA were investigated based on experiments and molecular dynamics simulation. Our findings suggest that maintaining an external epoxy group content between 8.4%similar to 11.4% in the CEA blend and below 12.17% in the cured CEA is crucial. These criteria can be met by adding no more than 5 wt% EHER. CEA with 3 wt% EHER exhibited the most balanced compatibility and mechanical properties, characterized by a pot life of 91 min, a tensile strength of 5.02 MPa, an elongation at break of 61.3%, and a tensile toughness of 1.58 MJ/m(3). The presence of external epoxy groups increased the cohesive energy density and the solubility parameter difference between epoxy resin and asphalt prior to curing, forming a "sea-island" structure with varying particle sizes, primarily comprising small-sized particles. This structure was preserved post-curing, establishing a stable system with minor energy alterations. Simultaneously, EHER enhanced the molecular rigidity and uniformity of CEA, thereby improving its mechanical properties. It is recommended to relate epoxy group content in CEA blends with indicators of compatibility and mechanical properties, enabling better prediction.
摘要：
Establishing durable asphalt pavement is crucial for realizing green roads. The strength model is the calculation basis for the design of durable pavement structures. Existing strength models for cement-stabilized macadam (CSM) typically derive from static load strength tests, neglecting the impact of loading rates. Firstly, this study validated the strength model under three-dimensional stress state using true triaxial compression test data of CSM and determined the parameters of the strength model. And by conducting uniaxial compression (UC), direct tension (DT), and indirect tensile (IT) strength tests under static and dynamic load conditions, simplified strength model parameters were determined under different loading modes. Then, we calculated the strength under a three-dimensional (3D) stress state of CSM based on simplified strength models with different loading rates, studied the relationship between the strength and loading rate. Finally, the relationship between the parameters of the simplified strength model under dynamic load conditions and the loading rate (v) was established, the dynamic strength model under a 3D stress state of CSM was determined. Using the correlation between driving speed and loading rate, the strength models of CSM for different grades of highways were determined. The results indicate that there is a significant difference between triaxial compression strength and the strength calculated by the simplified strength model under different loading rates. The strength with a loading rate of 50 MPa/s can reach about twice the triaxial compression strength. As the v increases, the strength under the 3D stress state increased in a power function. The strength model parameters under 3D stress state of CSM were related to the v as a linear relationship. Due to different driving speeds, the strength models of CSM of different levels of highways varied. This work makes the strength models of CSM more complete and improves the accuracy of CSM layer design.
通讯机构：
[Chen, Y ] C;Changsha Univ Sci & Technol, Traff & Transportat Engn Coll, Changsha, Peoples R China.
关键词：
highway construction project;carbon emission;scenario prediction;LSTM model;Hunan province
摘要：
In order to carry out the research on the measurement and prediction of carbon emissions from highway projects, the prediction index system is constructed by selecting seven influencing factors, namely, urbanization rate, industrial structure, energy intensity, energy structure, key low-carbon technologies, highway construction planning, and green financial support. The carbon emission coefficient method is used to measure the carbon emissions of highway projects from the perspective of energy consumption, and finally, a carbon emission scenario prediction model based on the scenario analysis method and the LSTM algorithm of the recurrent neural network is constructed to put forward a new way of predicting the carbon emissions of highway projects. Taking Hunan province as a case study object, the carbon emission trends in the next 15 years are predicted under three scenarios: low carbon, baseline, and high carbon. The results show that the highway project in Hunan province is expected to peak in 2031 under the low-carbon scenario, in 2037 under the baseline scenario, and around 2044 under the high-carbon scenario. It is also found that energy saving and emission reduction measures have a certain lag in the emission reduction effect of highway projects. Finally, based on this, suggestions and countermeasures for carbon emission reduction of highway development in Hunan province are proposed.
摘要：
The low thermal conductivity of phase change material limits its heat storage and cooling effect in asphalt pavement. Considering the multi -layer structure of asphalt pavement, conducting orientated heat induction in the asphalt layer outside the phase change asphalt layer is a novel approach to improve the temperature regulation ability of phase change asphalt pavement. As a result, this paper designed a heat storage and heat induction structure (HS -HIS) by combining the heat -storage top layer and the heat -induction middle and bottom layer. A finite element model was established to study the thermal behavior of HS -HIS and an indoor irradiation test was designed to verify the simulation results. The simulation results show that compared with control structure (CS), the heat storage in the top layer of HS -HIS increased by 14.9 %, while the heat accumulation in the middle layer decreased by 8.7 %, resulting in a decrease in heat flow and temperature inside the pavement. The peak temperature on the surface and at 4 cm depth was 0.5 degree celsius (11: 00 a.m.) and 2.6 degree celsius (13: 00 p.m.) lower than those of CS. Meanwhile, there was a good correlation between the indoor irradiation results and the simulation results. The above results indicate that HS -HIS can be used to effectively enhance heat directional transfer and improve the cooling effect of phase change asphalt pavement.
关键词：
eucalyptus plantation;sliding time window;LandTrendr;Google Earth Engine (GEE);historical dynamic
摘要：
Eucalyptus plantations are expanding rapidly in southern China owing to their short rotation periods and high wood yields. Determining the plantation dynamics of eucalyptus plantations facilitates accurate operational planning, maximizes benefits, and allows the scientific management and sustainable development of eucalyptus plantations. This study proposes a sliding-time-window change detection (STWCD) approach for the holistic characterization and analysis of eucalyptus plantation dynamics between 1990 and 2019 through dense Landsat time-series data. To achieve this, pre-processing was first conducted to obtain high-quality reflectance data and the monthly composite maximum normalized-difference vegetation index (NDVI) time series was determined for each Landsat pixel. Second, a sliding time window was used to segment the time series and obtain the NDVI change characteristics of the subsequent segments, and a sliding time window-based LandTrendr change detection algorithm was applied to detect the crucial growth or harvesting phases of the eucalyptus plantations. Third, pattern-matching technology was adopted based on the change detection results to determine the characteristics of the eucalyptus planting dynamics. Finally, we identified the management history of the eucalyptus plantations, including planting times, generations, and rotation cycles. The overall accuracy of eucalyptus identification was 90.08%, and the planting years of the validation samples and the planting years estimated by our algorithm revealed an apparent correlation of R2 = 0.98. The results showed that successive generations were mainly first- and second-generations, accounting for 75.79% and 19.83% of the total eucalyptus area, respectively. The rotation cycles of the eucalyptus plantations were predominantly in the range of 4-8 years. This study provides an effective approach for identifying eucalyptus plantation dynamics that can be applied to other short-rotation plantations.
摘要：
This paper studies fabric properties with the evolution of sand liquefaction by performing a series of 3D constant -volume cyclic triaxial DEM tests. With calibrated parameters for HN31 sand, the consistency between the obtained DEM results and the counterpart experiments is presented. The evolution of fabric characteristics is then assessed with the coordination number and mechanical coordination number, respectively. For liquefaction is-sues, the conventional coordination number outperforms the mechanical one since the floating particles with the number of contacts less than or equal to 1 can be fully considered. To analyse the complex inter-particle contacts in a granular assembly, the second-order contact normal fabric tensor is briefly introduced with its important mathematical properties. The second invariant of its deviatoric part can prove to be a proper index describing the degree of anisotropy in the principal fabric space spanned by the three eigenvectors belonging to this tensor. Following the direction of the applied loading, the fabric anisotropy accumulates in a gradual manner and finally reaches a threshold value corresponding to liquefaction triggering on the macro scale. This value is fabric -dependent and thus independent of loading intensity. For gaining a complete insight of sand liquefaction on both the micro and macro scales, the shear strain can act as a bridge to describe the evolution of coordination number and the anisotropy degree, respectively.
通讯机构：
[Liu, CC ] C;Changsha Univ Sci & Technol, Natl Key Lab Green & Long Life Rd Engn Extreme Env, Changsha 410114, Hunan, Peoples R China.
关键词：
SBS composite rejuvenating agent;Reclaimed asphalt pavement;Hot in -place recycling;Road -related properties;Engineering verification
摘要：
This study aims to supplement the degraded SBS components and improve the road-related properties of Hot in-place recycling (HIR) asphalt mixtures. Under the direct-to-plant process, a composite rejuvenating agent (SBS-CRA) composed of instant SBS, regenerant, and coupling agent is used to regenerate the HIR asphalt/asphalt mixture. Explore the effects of SBS-CRA on the properties and chemical composition of extracted asphalt using rheological and Fourier transform infrared spectroscopy tests. Evaluate the road-related properties and microstructure of SBS-CRA modified HIR asphalt mixtures under the direct-to-plant process through high and low temperature, water stability, fatigue, and scanning electron microscopy tests. And conduct performance verification by paving the test road. The research results indicate that the SBS-CRA can promote extracted asphalt's low-temperature behavior and viscosity while maintaining excellent high-temperature behavior. Under the direct-to-plant process, the SBS-CRA modified HIR asphalt mixture's high and low-temperature behavior and water stability comply with the specified requirements. After SBS-CRA regeneration, the asphalt on the surface of RAP material is smooth. Considering the road-related properties of SBS-CRA modified HIR asphalt mixture, the optimal recommended dosage of SBS-CRA is 5%, and the optimal mixing time of SBS-CRA and RAP material is recommended to be 120 s. At a 5% SBS-CRA content, the fatigue life of the HIR asphalt mixture is 407.9 times higher than that of the neat asphalt mixture. The on-site test results show that the freeze-thaw splitting strength ratio of the HIR asphalt mixture is 88.76%, which meets the specification requirements. The laboratory and on-site test results have proven that applying SBS-CRA in HIR technology is feasible.
期刊：
International Journal of Pavement Research and Technology,2024年17(1):36-52 ISSN：1996-6814
通讯作者：
Qinxue Pan<&wdkj&>Cece Zheng
作者机构：
[Qinxue Pan; Huaide Zhou; Cece Zheng; Hongfu Liu; Songtao Lv; Junhui Zhang; Defang Yue] Key Laboratory of Road Structure and Material of Ministry of Transport (Changsha), School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha, China;[Xiaojin Song] Hunan Huacheng Testing Technology Group Co., Ltd, Changsha, China;[Bo Yang] Chongqing Jiaotong University, Chongqing, China
通讯机构：
[Qinxue Pan; Cece Zheng] K;Key Laboratory of Road Structure and Material of Ministry of Transport (Changsha), School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha, China<&wdkj&>Key Laboratory of Road Structure and Material of Ministry of Transport (Changsha), School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Changsha, China
摘要：
In view of the non-uniqueness of modulus selection and the mismatch among the values of various mechanical parameters of the same material in the current asphalt pavement design, typical pavement materials, asphalt mixture (AC), and cement stabilized macadam (CSM) were selected to perform unconfined compressive, direct tensile, bending, and splitting tensile tests. Then, the quantitative matching relationships among the mechanical parameters were established considering the velocity dependence and the different properties of tension and compression. Moreover, the superiority–inferiority of the four test methods was also evaluated by analyzing the stability and change law of test data and the specimens force characteristics. The results show that the difference in tension and compression of strength and modulus was the inherent attribute of the materials, which leads to the non-uniqueness of the mechanical parameters. The unconfined compressive and direct tensile tests are suitable methods to obtain mechanical parameters of pavement materials. The ratio of the direct tensile strength (modulus) to unconfined compressive strength (modulus) of AC decreases (increases) with the loading rate, while those of CSM shows an opposite regular pattern, and these above ratios of the two pavement materials tend to be a fixed value at higher loading rates. This research can provide a reference for the scientific selection and proper value of mechanical parameters in asphalt pavement design.
关键词：
Road engineering;Solar pavement;Photovoltaic power generation;Light transmittance;Anti-skid performance;Economic evaluation
摘要：
Solar pavement can convert sunlight shining on the pavement surface into clean electricity through photovoltaic panels, thereby transforming the energy structure of road transportation. In order to balance the light transmittance and anti-skid resistance of the solar pavement surface, this study proposed a concentrated photovoltaic panel (CPP) structure for pavement. The panel structure was optimized, and a laboratory model was developed. The mechanical properties and durability of the panel were tested by the multi-functional material test system (MTS) and the model mobile load simulator 3 (MMLS3). Furthermore, the electrical performance was evaluated by an outdoor test, followed by an economic evaluation. The results show that the optimal structural dimensions of the CPP for pavement are 540 mm long × 540 mm in length × 144.62 mm in thickness. The maximum flexural tensile strength of its anti-skid concentrated panel is 61.67 MPa, satisfying the requirements of the traffic load. After 1.35 million cycles of loading, the surface of the anti-skid concentrated panel is free of cracks and deformation and has no obvious wear, exhibiting good transmittance durability and excellent wear resistance. In addition, the overall structure of the panel counteracts the light loss effect of the material and improves the light concentration performance, providing a gain effect on the power generation of the panel, especially in the case of high irradiance. The return on investment (ROI) of CPP for pavement is 54.42%, with cost recovery in 9.87 years. The levelized cost of energy is 0.67 CNY/kWh, indicating significant economic benefits. At the same time, 1539.3 kg/m2 of CO2 emissions can be avoided during the operation cycle, and the environmental benefits are also considerable. This study can provide a reference for the promotion and application of photovoltaic power generation technology in road engineering.
期刊：
Rock Mechanics and Rock Engineering,2024年:1-17 ISSN：0723-2632
通讯作者：
Shi, XL
作者机构：
[Ma, Hongling; Shi, Xilin; Li, Huan] Chinese Acad Sci, Inst Rock & Soil Mech, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Hubei, Peoples R China.;[Li, Huan] Jiangxi Acad Sci, Inst Energy Res, Nanchang 330096, Peoples R China.;[Li, Huan] Jiangxi Carbon Neutralizat Res Ctr, Nanchang 330096, Jiangxi, Peoples R China.;[Zhang, Haina] East China Jiaotong Univ, Coll Civil Engn & Architecture, Nanchang 330013, Jiangxi, Peoples R China.;[Zhang, Haina] Changsha Univ Sci & Technol, Key Lab Rd Struct & Mat, Minist Transport Changsha, Changsha 410114, Hunan, Peoples R China.
通讯机构：
[Shi, XL ] C;Chinese Acad Sci, Inst Rock & Soil Mech, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Hubei, Peoples R China.
关键词：
Bedded rock salt;Feasibility analysis;Dilatancy safety factor;Geomechanical model;Numerical simulation
摘要：
Based on traditional evaluation indexes, i.e., displacement, volume shrinkage, and equivalent strain, a new safety evaluation system, including the dilatancy safety factor (DSF) of bedded salt rock and failure approach index (FAI), is proposed in this work. Taking the Jianghan gas storage as the engineering background, the feasibility and stability of ultra-large underground gas storages (UGSs) in the Jianghan plain are demonstrated through this evaluation system. A 3D numerical model is implemented based on geological survey results and mechanical parameters of the Jianghan salt district. Subsequently, preferred geometric diameter and operating parameters, including cavern diameter, allowable pressure range, gas production rate, safety pillar width, and operation mode, are determined through a wide range of simulations. Results show that the suitable diameter is 80 m, the allowable pressure range is 16-34 MPa, the reasonable gas production rate is 0.5-0.6 MPa/d; a safe pillar width should be 2-3 times the cavern diameter, and the preferred operating mode should be synchronous injection-production mode. The simulation results, showing a high consistency with the previous research results, indicate the effectiveness and reliability of the proposed evaluation system. This work provides an alternative solution for the safety assessment method and design purposes for the UGSs in bedded salt rock. A new safety evaluation system for bedded salt cavern gas storage is proposed.A 3D geomechanical model of Jianghan salt cavern is implemented.The dilatancy boundary curves of bedded salt rock in China are presented.A complete set of operating parameters for Jianghan gas storage are optimized.
摘要：
To study the disintegration behavior and characterization indexes of Modified Graded Carbonaceous Mudstone (MGCM), soaking disintegration tests of MGCM under vertical loading and cyclic drying-wetting were carried out with a disintegration test instrument which self-designed by our team. The grain size distribution of MGCM during drying-wetting cycles was analysed. Standard basal entropy, as an important parameter of grading entropy that quantitatively characterizes distribution curves, was introduced to characterize the disintegration behavior of MGCM and correlated with the comprehensive evaluation index, namely, disintegration ratio. The results show that as the number of drying-wetting cycles increases, the Graded Carbonaceous Mudstone (GCM) blocks disintegrate rapidly and the fine-grain content increases. With an increase in vertical load, the particles disintegrate more completely. The contents of each particle group in the GCM test groups stabilize after 9, 7, and 4 drying-wetting cycles under vertical loads of 0, 100, and 200 kPa, respectively. Under the same vertical load of 200 kPa, the contents of each particle group in MGCM test groups with Polyurea (PU) content 0, 5, and 10 wt% stabilize after 4, 6, and 8 drying-wetting cycles, respectively. The inclusion of PU can effectively retard the disintegration of GCM, and the effect is more pronounced with 5 wt% PU content compared to 10 wt%. However, it is also susceptible to the deterioration of PU layer caused by mechanical screen. The grading entropy model of MGCM under loading and cyclic drying-wetting is established. There is a significant positive, linear correlation between the standard basal entropy and the disintegration ratio. A smaller standard basal entropy to a smaller disintegration ratio, indicating a greater degree of particle disintegration and fragmentation. The standard basal entropy can characterize the disintegrated particles of MGCM with different PU content under vertical loading and drying-wetting cycles. The standard basal entropy of GCM decreases rapidly initially and then stabilizes as the number of drying-wetting cycles increases. The standard basal entropy decreases exponentially as the vertical load increases. The results provide a new quantitative index for analyzing the grading characteristics of MGCM following disintegration, which are valuable for engineering construction and disaster prevention in carbonaceous mudstone areas.
期刊：
Accident; analysis and prevention,2024年200:107559
作者机构：
[Wu, Wei] Chongqing Key Laboratory of Intelligent Integrated and Multidimensional Transportation System, Chongqing Jiaotong University, 66 Xuefu Avenue, Nanan District, Chongqing 400074, China;[Wu, Wei] Department of Traffic and Transportation Engineering, Changsha University of Science & Technology, 960 Wanjiali South Road, Changsha, Hunan 410114, China. Electronic address: weiwu@cqjtu.edu.cn;[Chen, Siyu] Department of Traffic and Transportation Engineering, Changsha University of Science & Technology, 960 Wanjiali South Road, Changsha, Hunan 410114, China. Electronic address: chensiyu4557@stu.csust.edu.cn;[Xiong, Mengfei] Department of Traffic and Transportation Engineering, Changsha University of Science & Technology, 960 Wanjiali South Road, Changsha, Hunan 410114, China. Electronic address: xiongxiongfei@stu.csust.edu.cn;[Xing, Lu] Department of Automation, Beijing National Research Center for Information Science and Technology, Tsinghua University, China
摘要：
Existing studies on autonomous intersection management (AIM) primarily focus on traffic efficiency, often overlooking the overall intersection safety, where conflict separation is simplified and traffic conflicts are inadequately assessed. In this paper, we introduce a calculation method for the grid-based Post Encroachment Time (PET) and the total kinetic energy change before and after collisions. The improved grid-based PET metric provides a more accurate estimation of collision probability, and the total kinetic energy change serves as a precise measure of collision severity. Consequently, we establish the Grid-Based Conflict Index (GBCI) to systematically quantify collision risks between vehicles at an autonomous intersection. Then, we propose a traffic-safety-based AIM model aimed at minimizing the weighted sum of total delay and conflict risk at the intersection. This entails the optimization of entry time and trajectory for each vehicle within the intersection, achieving traffic control that prioritizes overall intersection safety. Our results demonstrate that GBCI effectively assesses conflict risks within the intersection, and the proposed AIM model significantly reduces conflict risks between vehicles and enhances traffic safety while ensuring intersection efficiency.
