Statistics and Probability Commons^™

Study On Effect Of Fiber Stabilizers On Water Temperature Cycle Damage Resistance Of Drainage Asphalt Mixtures, Liu Fuming, Wu Di, He Qingde, Yang Zhiping

Journal of China & Foreign Highway

In order to study the effect of fiber stabilizer on the water temperature cycle damage resistance of drainage asphalt mixture, drainage asphalt mixture without fiber stabilizer and with wood fiber, polyester fiber, and basalt fiber, respectively, were compared through tests. By standard dispersion test and immersed dispersion test, the anti-spalling ability of the mixture was analyzed. Under the same asphalt condition, the standard dispersion loss of the drainage asphalt mixture was reduced to different degrees after adding fiber stabilizer, which could increase the anti-spalling property of the drainage asphalt mixture to some extent. The splitting, indirect tensile, and rutting tests …

Experimental Analysis On Recycling And Mechanical Properties Of Waste Cement, Chen Liang

Journal of China & Foreign Highway

In order to recycle waste cement, construction waste cement materials were collected in the laboratory, and they were crushed, ground, and heat treated to facilitate reuse. Then, the waste cement was combined with the commonly used active fly ash admixture to prepare a new cement material for test analysis. The results show that the new cement material produced by industrial by-product, fly ash and waste cement material is feasible. A small amount of construction waste cement material (about 5%) can increase the 28-day compressive strength of cement by more than 50%, and the compressive strength of the prepared building material …

Experimental Study On Characteristics And Stability Of Different Aged Steel Slag Aggregate, Zhang Hongri, Wang Guiyao, Feng Jian, Lan Tianzhu, Wu Tao

Journal of China & Foreign Highway

Steel slag aggregate has good building material properties, but the utilization rate of steel slag in road engineering is low at present. In this paper, the chemical composition, basic physical and mechanical indexes, f⁃CaO, f⁃MgO, pulverization rate, CRB expansion rate, and other indexes of open-air aged steel slag aggregate in Fangchenggang, Guangxi Province for 0, 6, and 12 months were studied. The results show that the physical and mechanical properties of steel slag aggregate basically meet the requirements of road base materials and subgrade fillers, but the indexes of f⁃CaO, pulverization rate, and CRB expansion rate of steel slag aggregate …

Influence Factors Of Deicing And Thaw Performance Of Asphalt Mixture With Low Freezing Point, Zhou Shuiwen, Lin Fang, Zhang Xiaohua, Zhang Lingbo, Jiang Haoqiu

Journal of China & Foreign Highway

The conductivity test was used to study the release law of thawing and deicing components. The freezing test was used to study the cooling law of the mixture, and the thawing rate test was used to study the thawing and deicing performance. The results show that the release of thawing and deicing components of materials with a low freezing point is temperature-dependent, and the release at the high temperature is 3.49–3.77 times that at the low temperature. The granular materials tend to dissolve in water, which results in the release rate of thawing and deicing components faster than that of …

Evaluation Of Anti‐Cracking Performance Of Recycled Concrete With Recycled Rubber/Sbs Composite Modified Asphalt, Li Xiaobin

Journal of China & Foreign Highway

In order to improve the crack resistance of recycled asphalt mixture, a new styrenic block copolymer (SBS)/rubber composite modified asphalt with excellent crack resistance was proposed for the regeneration of reclaimed asphalt pavement (RAP). Based on the creep of low temperature bending beam, confined temperature stress, and four-point bending fatigue test, the low temperature cracking resistance and fatigue cracking performance of composite modified asphalt and SBS-modified asphalt were studied. The results show that the addition of rubber can improve the low temperature and medium temperature crack resistance of recycled asphalt concrete, which may be related to the propagation of micro-cracks …

Study On Anti‐Scattering Performance Of Asphalt Concrete On Aggregate Scattering Pavement Of Highway, Yang Siyuan, Chen Guiliang

Journal of China & Foreign Highway

Due to the lack of quantitative evaluation methods for aggregate scattering degree of expressway asphalt pavement in China and abroad, according to the disease characteristics of surface layer spalling, this paper adopted the Cantabro standard dispersion test to sample the concrete of the section with aggregate scattering of Huangqunan Expressway (G3) in Zhejiang Province. The dispersion impact damage modes of the mixture with different severity were analyzed, and the anti-dispersion performance of concrete was evaluated by mass loss rate and water absorption rate. The results show that aggregate scattering will reduce the density of the concrete structure at the surface …

Variable Speed Limit Control Method For Highway Under Dense Fog, Sun Jiancheng, Qiao Jiaxing

Journal of China & Foreign Highway

In order to solve the problem of traffic safety on expressways under dense fog and change the original fixed speed limit measures, a variable speed limit control method based on the safe allowable speed was proposed. The speed limit value was calculated based on the regulations in road traffic safety law on the speed under dense fog by considering that the traffic law does not mention the road alignment conditions, road conditions, and other factors, and the monitor data was used to approximate replace the data of individual vehicles for data optimization, and the safe speed and safe distance of …

Design And Experimental Study On Special Spherical Support Of Pingtang Bridge, Tang Zhi, Ma Baihu, Du Bin, Xu Xiangdong, Xia Junyong

Journal of China & Foreign Highway

The vertical bearing capacity of the 16# pier of Pingtang Bridge is 10 000 kN, and the horizontal bearing capacity along the bridge is 12 000 kN, which is 120% of the vertical bearing capacity. The support angle needs to reach the technical parameter requirements of 0.05 rad, which far exceeds the requirements of 10–40% horizontal force of conventional highway supports. According to the specific engineering situation, a new type of support with a large horizontal bearing capacity was designed. Firstly, the finite element model of the support was established to analyze the mechanical properties of the support, and the …

Study On Practical Method Of Safety Assessment For Bridges Under Heavy‐Cargo Transportation, Jiang Xu, Wang Wanfeng, He Zhensheng, Gao Xuefeng

Journal of China & Foreign Highway

In order to meet the requirements of the industry for the high efficiency, safety, and reliability of the traffic safety assessment of heavy-duty vehicles, this paper proposed a method that combined a real-time monitoring system with a finite element method for the traffic safety assessment of heavy-duty vehicles on bridges and verified the method through practical projects. The paper evaluated the bridge’s technical condition level before the heavy-duty vehicle passes and determined the resistance reduction factor considering the bridge’s technical condition level. The finite element analysis model of the bridge was established, and the reliability of the model was verified …

Research On Vibration Reduction Measures Of Short‐Hole Blasting For Pile Group Foundation Of Bridge, Long Lidun, Ji Zhongyan, Li Shaofang, Zhou Xu

Journal of China & Foreign Highway

In the construction of pile hole blasting of group pile foundation of bridges, due to the small clear distance between piles, the blasting vibration will have adverse effects on the wall protection of adjacent pile holes and the poured pile core concrete. Measures thus should be taken to control the seismic wave vibration velocity. In view of the inapplicability of conventional blasting vibration reduction measures such as reducing charge and setting isolation ditch in the construction of pile group foundation of the bridge, this paper proposed vibration reduction measures such as setting isolation holes and using air bags to replace …

Analysis Of Influence Parameters Of Steel Corrugated Plate‐Concrete Composite Arch Culvert, Zhang Haijun

Journal of China & Foreign Highway

In order to explore the parameter effect of a composite arch culvert with corrugated steel plate and concrete, based on the engineering background of a composite arch culvert, the influence rules of four parameters, namely fill height, pipe diameter, wall thickness, and uneven settlement, on the stress and deformation of the arch culvert were analyzed based on the control variable method. The results show that the deformation and stress of the arch culvert are positively correlated with the fill height h and pipe diameter R. When h < 25 m, the deformation and stress increase linearly with the increase in the fill height, and when h > 25 m, the deformation and stress increase in a curve form. When R …

Research And Analysis On Controlled Blasting Demolition Of Continuous Thin‐Walled Box Ribbed Arch Bridge, Ma Shaojun, Chen Huibin, Chai Wendong, Zhang Chunquan, Wang Yuan

Journal of China & Foreign Highway

The 1st bridge of the Jialing River in Pengan County is erected over the Jialing River, a tributary of the Yangtze River. Due to earthquakes and perennial high load operation, the overall technical condition is “Class Ⅴ”, which cannot meet the requirements of the design load grade. This bridge is the longest highway bridge dismantled in Sichuan Province. Its structure is a multi-span continuous thin-walled box ribbed arch bridge. In addition, there are obvious diseases, so the demolition is difficult, and the safety risk is great. For the demolition of the bridge by controlled blasting, numerical simulation, shaped charge cutting …

Study On Parameter Optimization Of Feet‐Lock Anchor Pipes Of Tunnels In Unconsolidated Formation, Tang Heqing, Jiang Xishan, Yang Peng

Journal of China & Foreign Highway

In order to give full play to the supporting role of the feet-lock anchor pipe in the tunnel with unconsolidated formation, it is necessary to obtain the optimal construction parameters of the feet-lock anchor pipe. Based on a tunnel project on the Huaping–Lijiang Expressway in Yunnan Province, this paper conducted numerical simulation and field test analysis. By comparing the arch subsidence and horizontal convergence of the supporting structure when the feet-lock anchor pipe with different parameters was constructed, the paper explored the characteristics and causes of the influence of construction parameters on the feet-lock effect. The results show that the …

Simulation Study On Flame Retardant Effect Of Warm‐Mixed Flame Retardant Pavement In Highway Tunnel

Journal of China & Foreign Highway

In order to obtain the flame retardant effect of the warm-mixed flame retardant asphalt pavement in highway tunnels, based on the finite element method and thermodynamics theory, the thermal analysis module of Ansys finite element software was used to study the flame retardant effect of ordinary asphalt pavement, flame retardant asphalt pavement, and warm-mixed flame retardant asphalt pavement under different fire scales. The maximum temperature of the three types of pavement increased with the increase in the fire scale. Under any fire scale, the flame retardant effect of the warm-mixed flame retardant asphalt pavement was increased by 4.9%–8.5% compared with …

Installation Construction Technology Of Composite Girder Cable‐Stayed Bridge Superstructure In Deep‐Cutting Gorge, Ren Lei, Lu Liang, Dong Zhengliang

Journal of China & Foreign Highway

In view of the installation problems of superimposed beam cable-stayed bridge across the deep canyon, this paper studied the superimposed beam lifting, transport on beam, and superimposed beam installation and proposed three kinds of lifting technology with tower truss crane, beam lifting door crane, and large tower crane, as well as two kinds of installation technology including piecemeal assembly by full rotating deck crane and whole segment assembly truss deck crane. It also made a relative comparative analysis, solving the difficulty in vertical lifting on such bridges and providing a reference for the construction of the same type of cable-stayed …

Experiment Research Of High Pressure Jet Grouting Pile On Ultra‐Shallow Buried Tunnel In Strong Weathered Stratum, Lu Liyang, Liu Huan, Li Pinpin

Journal of China & Foreign Highway

By taking the ultra-shallow buried construction of Xinwu Tunnel in Luoding–Xinyi Expressway in Guangdong Province as the engineering background, the key construction parameters and formation reinforcement effect of high-pressure rotary churning pile in ultra-shallow buried tunnel surrounding rock of fully weathered strata were compared. The results show that: ① slurry pressure, rotary churning speed, and lifting speed have obvious effects on the static load bearing capacity of a single pile. Under the same static load condition, greater slurry pressure indicates a lower cumulative settlement value of a single pile and a smaller increase in cumulative settlement value, and the change …

Study On Anti‐Scattering Performance Of Asphalt Concrete On Aggregate Scattering Pavement Of Highway, Yang Siyuan, Chen Guiliang

Journal of China & Foreign Highway

Due to the lack of quantitative evaluation methods for aggregate scattering degree of expressway asphalt pavement in China and abroad, according to the disease characteristics of surface layer spalling, this paper adopted the Cantabro standard dispersion test to sample the concrete of the section with aggregate scattering of Huangqunan Expressway (G3) in Zhejiang Province. The dispersion impact damage modes of the mixture with different severity were analyzed, and the anti-dispersion performance of concrete was evaluated by mass loss rate and water absorption rate. The results show that aggregate scattering will reduce the density of the concrete structure at the surface …

Variable Speed Limit Control Method For Highway Under Dense Fog, Sun Jiancheng, Qiao Jiaxing

Journal of China & Foreign Highway

In order to solve the problem of traffic safety on expressways under dense fog and change the original fixed speed limit measures, a variable speed limit control method based on the safe allowable speed was proposed. The speed limit value was calculated based on the regulations in road traffic safety law on the speed under dense fog by considering that the traffic law does not mention the road alignment conditions, road conditions, and other factors, and the monitor data was used to approximate replace the data of individual vehicles for data optimization, and the safe speed and safe distance of …

Application Of Digital Image Processing In Cracks Of Concrete Pavement, Gao Fan, He Chunguang, Wang Pengzhang, Qin Yanping, Duo Huaqiong

Journal of China & Foreign Highway

The image obtained by using the traditional crack detection method of concrete pavement has some problems, such as low contrast and high noise, which makes it difficult to meet the requirements of modern road engineering management or non-destructive testing. In order to eliminate the interference in crack images, digital image processing technology was used to improve the image quality through computers. This paper took digital image processing as the core and introduced its development and application in pavement cracks. Based on the research progress and achievements of digital image processing on pavement cracks in recent years, the principles and characteristics …

Design And Experimental Study On Special Spherical Support Of Pingtang Bridge, Tang Zhi, Ma Baihu, Du Bin, Xu Xiangdong, Xia Junyong

Journal of China & Foreign Highway

The vertical bearing capacity of the 16# pier of Pingtang Bridge is 10 000 kN, and the horizontal bearing capacity along the bridge is 12 000 kN, which is 120% of the vertical bearing capacity. The support angle needs to reach the technical parameter requirements of 0.05 rad, which far exceeds the requirements of 10–40% horizontal force of conventional highway supports. According to the specific engineering situation, a new type of support with a large horizontal bearing capacity was designed. Firstly, the finite element model of the support was established to analyze the mechanical properties of the support, and the …

Study On Practical Method Of Safety Assessment For Bridges Under Heavy‐Cargo Transportation, Jiang Xu, Wang Wanfeng, He Zhensheng, Gao Xuefeng

Journal of China & Foreign Highway

In order to meet the requirements of the industry for the high efficiency, safety, and reliability of the traffic safety assessment of heavy-duty vehicles, this paper proposed a method that combined a real-time monitoring system with a finite element method for the traffic safety assessment of heavy-duty vehicles on bridges and verified the method through practical projects. The paper evaluated the bridge’s technical condition level before the heavy-duty vehicle passes and determined the resistance reduction factor considering the bridge’s technical condition level. The finite element analysis model of the bridge was established, and the reliability of the model was verified …

Study On Pavement Performance Of Waterborne Epoxy Emulsified Asphalt And Its Application In Micro‐Surface, Jiang Hai, Liu Dachang

Journal of China & Foreign Highway

In order to improve the pavement performance at micro-surface, waterborne epoxy resin was used to modify the emulsified asphalt, and the compatibility, microstructure, mechanical properties, rheological properties, and pavement performance of mixtures of the modified emulsified asphalt were studied. The storage stability test shows that the epoxy emulsion has good compatibility with emulsified asphalt. With the increase in waterborne epoxy resin content, the modified emulsified asphalt tends to form an epoxy resin-dominated skeleton structure. At the same time, with the increase in waterborne epoxy resin content, the adhesion and mechanical properties of emulsified asphalt and aggregate are significantly improved. At …

Stochastic Optimization To Reduce Aircraft Taxi-In Time At Igia, New Delhi, Rajib Das, Saileswar Ghosh, Rajendra Desai, Pijus Kanti Bhuin, Stuti Agarwal

International Journal of Aviation, Aeronautics, and Aerospace

Since there is an uncertainty in the arrival times of flights, pre-scheduled allocation of runways and stands and the subsequent first-come-first-served treatment results in a sub-optimal allocation of runways and stands, this is the prime reason for the unusual delays in taxi-in times at IGIA, New Delhi.

We simulated the arrival pattern of aircraft and utilized stochastic optimization to arrive at the best runway-stands allocation for a day. Optimization is done using a GRG Non-Linear algorithm in the Frontline Systems Analytic Solver platform. We applied this model to eight representative scenarios of two different days. Our results show that without …

Occurrence Of Per- And Polyfluoroalkyl Substances (Pfas) In New Hampshire Biosolids, Katherine A. Wieck

Honors Theses and Capstones

Per- and polyfluoroalkyl substances (PFAS) are a group of over 4,000 compounds used in the manufacturing of products including aqueous film forming foams for firefighting, stain repellents, waterproofing agents, and nonstick cookware since their initial development in the 1940s. The long fluorinated carbon chain structure of PFAS causes chemical and thermal stability, and thus resistance to biodegradation. Biosolids produced at wastewater facilities for uses such as agricultural land-applied compost and fertilizer for lawns and athletic fields, as well as sludge disposed in landfills can cause contamination of groundwater and surface water. This poses a significant threat to human and environmental …

Joint Probability Analysis Of Extreme Precipitation And Water Level For Chicago, Illinois, Anna Li Holey

Dissertations, Master's Theses and Master's Reports

A compound flooding event occurs when there is a combination of two or more extreme factors that happen simultaneously or in quick succession and can lead to flooding. In the Great Lakes region, it is common for a compound flooding event to occur with a high lake water level and heavy rainfall. With the potential of increasing water levels and an increase in precipitation under climate change, the Great Lakes coastal regions could be at risk for more frequent and severe flooding. The City of Chicago which is located on Lake Michigan has a high population and dense infrastructure and …

Improving Data-Driven Infrastructure Degradation Forecast Skill With Stepwise Asset Condition Prediction Models, Kurt R. Lamm, Justin D. Delorit, Michael N. Grussing, Steven J. Schuldt

Faculty Publications

Organizations with large facility and infrastructure portfolios have used asset management databases for over ten years to collect and standardize asset condition data. Decision makers use these data to predict asset degradation and expected service life, enabling prioritized maintenance, repair, and renovation actions that reduce asset life-cycle costs and achieve organizational objectives. However, these asset condition forecasts are calculated using standardized, self-correcting distribution models that rely on poorly-fit, continuous functions. This research presents four stepwise asset condition forecast models that utilize historical asset inspection data to improve prediction accuracy: (1) Slope, (2) Weighted Slope, (3) Condition-Intelligent Weighted Slope, and (4) …

Impact Of Climate Oscillations/Indices On Hydrological Variables In The Mississippi River Valley Alluvial Aquifer., Meena Raju

Theses and Dissertations

The Mississippi River Valley Alluvial Aquifer (MRVAA) is one of the most productive agricultural regions in the United States. The main objectives of this research are to identify long term trends and change points in hydrological variables (streamflow and rainfall), to assess the relationship between hydrological variables, and to evaluate the influence of global climate indices on hydrological variables. Non-parametric tests, MMK and Pettitt’s tests were used to analyze trend and change points. PCC and Streamflow elasticity analysis were used to analyze the relationship between streamflow and rainfall and the sensitivity of streamflow to rainfall changes. PCC and MLR analysis …

Maximum Likelihood Estimator Method To Estimate Flaw Parameters For Different Glass Types, Nabhajit Goswami

Dissertations, Master's Theses and Master's Reports

Glass is commonly used in architectural applications, such as windows and in-fill panels and structural applications, such as beams and staircases. Despite the popularity of structural glass use in buildings, an engineering design standard to determine the required component or member strength for design loads does not exist. Glass is a brittle material that lacks a well-defined yield or ultimate stress, unlike ductile materials. The traditional engineering methods used to design a ductile material cannot be used to design a glass component. Glass fails in tension primarily due to the presence of microscopic flaws present on the surface that acts …

Investigating The Impacts Of Crash Prediction Models On Quantifying Safety Effectiveness Of Adaptive Signal Control Systems, Weimin Jin, Mashrur Chowdhury, Sakib Mahmud Khan, Patrick Gerard

Publications

Introduction: Adaptive Signal Control System (ASCS) can improve both operational and safety benefits at signalized corridors. Methods: This paper develops a series of models accounting for model forms and possible predictors and implements these models in Empirical Bayes (EB) and Fully Bayesian (FB) frameworks for ASCS safety evaluation studies. Different models are validated in terms of the ability to reduce the potential bias and variance of prediction and improve the safety effectiveness estimation accuracy using real-world crash data from non-ASCS sites. This paper then develops the safety effectiveness of ASCS at six different corridors with a total of 65 signalized …

Computational Modeling For Decision-Making Under Climate Change Uncertainty: Reservoir Simulation Game, Julianne Quinn

All ECSTATIC Materials

Almost every decision you make is under uncertainty. Will I need a rain jacket in the afternoon? Will they say yes if I ask them out? Is 1 hour enough time to finish this assignment? Oftentimes, we can use computational modeling to simulate different scenarios of what might happen in the future to inform what decisions are best on average, or what decisions minimize the worst case outcome. For example, you could decide what player to draft for your Fantasy Football team by simulating player performance. In this activity, we will simulate how much water to release from a dam …