scholarly journals Use of Foamed Cement Banking for Reducing Expressways Embankment Settlement

2021 ◽  
Vol 11 (24) ◽  
pp. 11959
Author(s):  
Yuedong Wu ◽  
Hui Liu ◽  
Jian Liu
Keyword(s):  
Traffic Safety ◽  
Calculation Method ◽  
Load Ratio ◽  
Normal Operation ◽  
Soft Ground ◽  
Construction Period ◽  
Road Closure ◽  
The Impact ◽  
Settlement Monitoring ◽  
Embankment Stability

Expressways are often built on soft ground, the foundation of which is not processed adequately during the construction period. Consequently, the traffic safety and embankment stability will be seriously affected due to uneven settlement. The technology of holing the embankment and replacing foamed cement banking (FCB) could control the settlement of an embankment without road closure, thus reduce the impact of construction on normal operation of highways. In this paper, the principle of FCB is described. Additionally, a sedimentation ratio calculation method, through the analysis of the settlement load ratio, is proposed for calculating the roadbed replacement thickness. This paper takes the example of the test section EK0 + 323 on Shen-Jia-Hu expressway in Zhejiang Province and combines with site settlement monitoring data to confirm the effectiveness of the calculation method proposed.

scholarly journals Study on the Influence of Slope on Pollutant Diffusion Characteristics during Tunnel Construction Period

2019 ◽  
Vol 118 ◽  
pp. 04005
Author(s):  
Zubin Ai ◽  
Zhongqiang Song ◽  
Fan Chen ◽  
Song Yang ◽  
Zhensheng Cao ◽  
...  
Keyword(s):  
Wind Speed ◽  
Traffic Safety ◽  
Reduction Rate ◽  
Tunnel Construction ◽  
Tunnel Length ◽  
Construction Period ◽  
Diffusion Characteristics ◽  
Speed Up ◽  
The Impact ◽  
Dust Reduction

. The relative elevation of the beginning and end of the Jianyuan Expressway exceed 1000m. In order to overcome the impact of the large slope on traffic safety, a spiral tunnel was designed in the middle of the expressway. The tunnel length is 3970m and the radius is 710~730m with its slope being up to 2.08%. The occurrence of large slope has a great impact on ventilation and smoke during tunnel construction, but little research has been done before. In this paper, numerical simulation and field test were used to study the effect of slope on the diffusion characteristics of pollutants. It was found that as the slope increased, the wind speed and CO dilution rate also increased. However, the dust dilution characteristics were different. Especially in the case of the downward tunnel, the effect of wind speed on the sedimentation rate of dust was minimal. Simply increasing the wind speed cannot speed up the dust reduction rate.

scholarly journals Assessing inequality, irregularity, and severity regarding road traffic safety during COVID-19

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lei Lin ◽  
Feng Shi ◽  
Weizi Li
Keyword(s):  
New York ◽  
Los Angeles ◽  
Traffic Safety ◽  
Traffic Accidents ◽  
Road Traffic ◽  
Human Mobility ◽  
Critical Conditions ◽  
Road Traffic Safety ◽  
Accident Data ◽  
The Impact

AbstractCOVID-19 has affected every sector of our society, among which human mobility is taking a dramatic change due to quarantine and social distancing. We investigate the impact of the pandemic and subsequent mobility changes on road traffic safety. Using traffic accident data from the city of Los Angeles and New York City, we find that the impact is not merely a blunt reduction in traffic and accidents; rather, (1) the proportion of accidents unexpectedly increases for “Hispanic” and “Male” groups; (2) the “hot spots” of accidents have shifted in both time and space and are likely moved from higher-income areas (e.g., Hollywood and Lower Manhattan) to lower-income areas (e.g., southern LA and southern Brooklyn); (3) the severity level of accidents decreases with the number of accidents regardless of transportation modes. Understanding those variations of traffic accidents not only sheds a light on the heterogeneous impact of COVID-19 across demographic and geographic factors, but also helps policymakers and planners design more effective safety policies and interventions during critical conditions such as the pandemic.

The Uneven Settlement Cause and Settlement Prediction of Xi Ying Sluice

2015 ◽  
Vol 733 ◽  
pp. 116-119
Author(s):  
Qing Yuan Zhu ◽  
Li Ting Qiu ◽  
Ting Jiang
Keyword(s):  
Three Dimensional ◽  
Normal Operation ◽  
Wall Structure ◽  
Construction Period ◽  
Settlement Prediction ◽  
Concrete Pile ◽  
Operation Period ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Design Construction

Xi Ying sluice built in Xishi River, Changzhou City, is a single span sluice with width of 6m. The chamber is pier wall structure of depressed reinforced concrete floor, when the chamber had a filling and discharging water during construction period, we found that the chamber appeared large uneven subsidence. According to the design, construction and other specific circumstances of Xi Ying sluice, by using three-dimensional finite element method to calculate and analyzed the settlement of the sluice, we studied on the genesis of the uneven settlement and predicted the settlement after the running. Analysis shows that the chamber of the uneven settlement is due to the jacking effect of concrete pile. The settlement has been basically completed caused by chamber weight, there will not be a substantial settlement; In the case of blocking water during operation period, chamber’s settlement increment outside the river side and inside the river side are respectively 0.3mm and 0.4mm; through processing, the settlement of chamber won’t affect the normal operation of sluice.

Road barriers: modern solutions for improving traffic safety

2021 ◽  
pp. 43-48
Author(s):  
Keyword(s):  
Traffic Safety ◽  
Traffic Accident ◽  
Preventive Measures ◽  
Mechanical Damage ◽  
Road Accidents ◽  
Road Users ◽  
Urgent Task ◽  
The Moment ◽  
Energy Absorbing ◽  
The Impact

Improving the system of preventive measures aimed at reducing the severity of the consequences of road accidents is an urgent task. Road deaths are constantly increasing and there is a need for a comprehensive approach to creating safe road conditions. The purpose of this study is to analyze the promising designs of road barriers designed to prevent uncontrolled exit of vehicles from the roadway of the highway and to develop the design of energy-absorbing fencing. Barrier barriers must not only be safe for road users, but must also ensure their safety, as well as preserve the elements after hitting the fence. Analytical studies have shown that in order to reduce mechanical damage to vehicles and reduce the severity of injuries to the driver and passengers, it is necessary to develop a road fence design that allows you to extinguish the impact energy at the moment of contact between the car and the fence. Keywords: fencing, barrier, safety, traffic accident

scholarly journals Incidence and causes of lower-limb amputations in the city of Ribeirão Preto from 1985 to 2008: evaluation of the medical records from 3,274 cases

2016 ◽  
Vol 19 (2) ◽  
pp. 317-325 ◽  
Author(s):  
Bruna Maria Bueno Barbosa ◽  
Rosane Aparecida Monteiro ◽  
Lucas Françolin Sparano ◽  
Rodolfo Fabiano Niz Bareiro ◽  
Afonso Dinis Costa Passos ◽  
...  
Keyword(s):  
Traffic Safety ◽  
Lower Limb ◽  
Population Aging ◽  
Average Rate ◽  
Control Program ◽  
Diabetes Control ◽  
Ischemic Complications ◽  
The Impact ◽  
The City ◽  
Alcohol Laws

ABSTRACT: Objective: It was to identify trends of traumatic and non-traumatic causes of lower limb amputations, as well as the role played by population aging, traffic violence increase, public health policy of diabetes control program and drivers anti-alcohol laws on these amputations. Method: Hospitalization data recorded in the discharge forms of 32 hospitals located in the region of Ribeirão Preto, Brazil, from 1985 to 2008 were analyzed. Result: A total of 3,274 lower-limb amputations were analyzed, of which 95.2% were related to non-traumatic causes, mainly infectious and ischemic complications of diabetes mellitus. Cancer (2.8%) and congenital (1.3%) causes were included in this group. Only 4.8% were related to traumatic causes. Traumatic amputation average rate was 1.5 amputations in 100,000 habitants with a slight tendency of increase in the last 5 years. Non-traumatic causes showed an average rate of 30.0 amputations for 100,000 habitants and remained relatively constant during the whole period. Non-traumatic were much more predominant in patients older than 60 years and traumatic amputations occurred more frequently in patients younger than 39 years. Conclusion: The overall rates of amputation and the rates of traumatic and non-traumatic amputations remained nearly constant during the study period. The impact of diabetes control policies and the introduction of traffic safety laws could not be identified on the amputation rates.

Theoretical and Numerical Calculation on the Added Mass of Ahmed Body

2017 ◽  
Vol 865 ◽  
pp. 247-252
Author(s):  
Gui Tao Du
Keyword(s):  
Numerical Calculation ◽  
Theoretical Calculation ◽  
Calculation Method ◽  
Aerodynamic Drag ◽  
Added Mass ◽  
The Body ◽  
Power Performance ◽  
Car Body ◽  
The Impact ◽  
Ahmed Body

Because of the added mass, the aerodynamic drag of the automobile will increase obviously when accelerating in the still air. In this paper, it firstly gave the definition of the added mass, and presented that there was little research on the calculation of the added mass of automobile. Then through the analysis of the theoretical calculation method for the added mass, it pointed out that, for the added mass of the car-body with a complex shape, there was much difficulty in the theoretical calculation. Alternatively, a numerical calculation method for the added mass of car-body was derived. The simulation model adopted the Ahmed body and the corresponding verification experiment was completed in the Tongji Automotive Wind Tunnel center. The results indicate that the added mass is a constant which is only dependent on the body-shape. For the model investigated, the added mass is 0.0052kg that is approximately equal to the air displaced by the car-body. As the body accelerates to 4m/s2, the aerodynamic drag is increased by 1.89% because of added mass. Therefore, it needs to pay more attention to the impact that the added mass has on the dynamic performance of vehicle when proceeding the aerodynamic designs (especially for the high power performance vehicles). Meanwhile, it still makes a correction to the conventional aerodynamic drag formula. This paper also demonstrates that, with the analysis of the flow-field of car-body, the added mass essentially stems from the additionally work done by the car-body to increase the kinetic energy of external fluid as it speeds up.

scholarly journals Management of the formation of stocks of material resources of the enterprise

2021 ◽  
pp. 191-197
Author(s):  
A. Sumets
Keyword(s):  
Economic Effect ◽  
Normal Operation ◽  
Capital Investments ◽  
Analog Model ◽  
Manufacturing Enterprise ◽  
Logistics System ◽  
Material Resources ◽  
Industrial Enterprises ◽  
Net Profit ◽  
The Impact

The article deals with the problem of forming a reasonable level of stocks of material resources of the logistics system of a manufacturing enterprise. It was stated that in the share of material resources of industrial enterprises, the leading place is occupied by stocks of raw materials, materials, semi-finished products, and blanks. The latter belong to the category of inventories. Therefore, the management of this type of material resources is one of the most urgent tasks for enterprises. In this regard, there is a need for a modern approach to the problem of managing stocks of material resources and the economic assessment of the profitability of creating production and commercial stocks. And at the same time, one of the important questions is to determine their optimal volume. It was found that when forming stocks of material resources, it is necessary to simultaneously comply with the requirements for the sufficiency of their volume to ensure the normal operation of the enterprise's logistics system, to reduce their volume as much as possible while increasing the degree of mobility, and to minimize the total costs associated with the formation of stocks. An analog model for assessing the economic efficiency of the influence of changes in the size of the stock of material resources on the comparative economic effect of the logistics activities of an enterprise is proposed for practical use. This model takes into account the causal relationship between natural (partial) and cost (generalizing) indicators of the inventory management system of material resources and provides an opportunity to calculate the comparative economic effect of changes in the volume of inventories at the enterprise. In practice, this will make it possible to economically substantiate the decision on the need to form stocks of one or another type of material resources. It is shown that the economic effect of the functioning of the logistics system of a manufacturing enterprise is significantly influenced by the growth of fixed and circulating assets. To determine the assessment of the impact of the growth of fixed and current assets on the value of the economic effect, an analog model is proposed. The main structural elements of such a model are an increase in capital investments in fixed assets, an increase in profits from product sales, a change in logistics costs, an increase (savings) in investment in current assets, a change in the cost of production. These factors are directly related to the growth of depreciation charges, the increase in profits from the acceleration of inventory turnover and the increase in net profit. Taking into account the results of the studies performed, it was found that the economic effect is formed by the total discounted net profit and the amount of depreciation (provided there are no penalties) minus the total additional capital investments in the enterprise. To calculate the economic effect, a corresponding mathematical relationship is proposed. The key words: enterprise, stock, stock size, material resources, evaluation, relative economic effect.

Thermal–Mechanical Coupling Evaluation of the Panel Performance of a Prefabricated Cabin-Type Substation Based on Machine Learning

Fire ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 93
Author(s):  
Xiangsheng Lei ◽  
Jinwu Ouyang ◽  
Yanfeng Wang ◽  
Xinghua Wang ◽  
Xiaofeng Zhang ◽  
...  
Keyword(s):  
Neural Network ◽  
Machine Learning ◽  
Numerical Simulation ◽  
Fire Resistance ◽  
Bp Neural Network ◽  
Stress Test ◽  
Normal Operation ◽  
Model Parameters ◽  
Mechanical Coupling ◽  
The Impact

The panel performance of a prefabricated cabin-type substation under the impact of fires plays a vital role in the normal operation of the substation. However, current evaluations of the panel performance of substations under fire still focus on fire resistance tests, which seldom consider the relationship between fire behavior and the mechanical load of the panel under the impact of fires. Aiming at the complex and uncertain relationship between the thermal and mechanical performance of the substation panel under impact of fires, this paper proposes a machine learning method based on a BP neural network. First, the fire resistance test and the stress test of the panel is carried out, then a machine learning model is established based on the BP neural network. According to the collected data, the model parameters are obtained through a series of training and verification processes. Meanwhile, the correlation between the panel performance and fire resistance was obtained. Finally, related parameters are input into the thermal–mechanical coupling evaluation model for the substation panel performance to evaluate the fire resistance performance of the substation panel. To verify the correctness of the established model, numerical simulation of the fire test and stress test of the panel is conducted, and numerical simulation samples are predicted by the trained model. The results show that the prediction curve of neural network is closer to the real results compared with the numerical simulation, and the established model can accurately evaluate the thermal–mechanical coupling performance of the substation panel under fire.

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