Spiral Tunnel Research Articles

Analysis of Driver's Physiological Responses and Task Load in Curved and Spiral Tunnels: A Naturalistic Driving Experiment

Analysis of Driver's Physiological Responses and Task Load in Curved and Spiral Tunnels: A Naturalistic Driving Experiment

Technical innovation in the “Beishan No. 1” hard rock tunnel boring machine for high-gradient spiral tunnels

Technical innovation in the “Beishan No. 1” hard rock tunnel boring machine for high-gradient spiral tunnels

The cambrian gog quartzite and deadwood formations of alberta: lessons for subsurface carbon sequestration

Injecting carbon dioxide into reservoirs has been undertaken since the 1940s, mostly as a method to enhance oil recovery. With the recognition of the impact of climate change, interest in carbon sequestration has increased exponentially, with hundreds of projects in progress around the globe. Many of these projects focus on Cambrian quartzites, which meet the requirements for carbon dioxide injection (CCS). Several CCS projects in Alberta, Canada, currently focus on using these reservoirs, including the Basal Cambrian Sandstone and Deadwood Formations, for injection and storage.A series of spectacular outcrops of the Cambrian Gog Quartzite are available for study in the area around Lake Louise in the Canadian Rockies of Alberta. These outcrops provide compelling analogues to other clastic Cambrian formations in the province that have been utilized for CCS. As an example, the Gog Quartzite was used by Shell as a direct reservoir analogue when modeling CO2 injection into the Basal Cambrian Sandstone in the QUEST Project. The Gog Quartzite also has potential to act as a CCS reservoir in its own right and may reach 2 kilometres in thickness.Outcrops of the Gog Quartzite were studied at Sink Lake, Spiral Tunnels and in the vicinity of Lake Louise in Alberta. They include fluvial and shallow marine, high net:gross sandstone beds with stacked trough cross-bedded sandstones. These are commonly interbedded with thin mudstone beds. Sedimentary structures include planar and trough cross-beds, wave ripples and contorted horizons interpreted as seismites with associated dewatering. Some units of the Gog Quartzite are heavily bioturbated with burrows including Arenicolites and Skolithos as well as other marine traces such as trilobite related ichnofacies.The Cambrian Deadwood Formation is also a target for carbon dioxide sequestration and provides the main reservoir for the Aquistore Project in Saskatchewan. It has been targeted by exploration wells in eastern Alberta and a new core study has demonstrated its suitability as a CO2 reservoir. Facies ranging from regolith overlying igneous basement, through alluvial fan and tidal deposits, and out into shallow marine settings with well developed parasequences, are all seen in the cores.The outcrop and core studies provide new data on Cambrian reservoirs which can be applied directly to potential Cambrian CCS targets in the subsurface of Alberta. The data can also be used to identify other potential Cambrian CO2 sinks around the world.

Blasting dust diffuse characteristics of spiral tunnel and dust distribution model: similar experiment and numerical modeling.

The special linear shape of spiral tunnel changes the air flow structure during tunnel construction and changes the diffuse and distribution of blasting dust. Mastering the blasting dust distribution and diffuse mechanisms can provide theoretical basis for ventilation layout and dust removal measures during spiral tunnel construction. To study the influence of spiral shape on dust diffusion and concentration distribution after tunnel blasting, a similar scale model of 1:20 and full-scale numerical model of spiral tunnel during construction were established. The similarity criterion and the similarity ratio of each physical quantity are derived from the dust motion equation. The dust distribution and diffuse characteristics in the spiral tunnel under different dust release quantity and release velocity were studied by model experiment. The dust distribution and diffuse characteristics in spiral tunnel with different curvature radius were studied by numerical simulation. The dust distribution model is refined based on the research results. The dust distribution model divides the tunnel into heavily polluted area and slightly polluted area, and the influence characteristics of the curvature radius on the dust export area are found. The layout of ventilation systems can be optimized according to the volume of heavily polluted areas. The heavily polluted area should be as small as possible; the dust in the heavily polluted area should be discharged to the slightly polluted area in an orderly manner to avoid the accumulation of dust. Dust removal measures can also be arranged according to the dust export location to improve dust removal efficiency.

Research on Spiral Tunnel Exit Speed Prediction Model Based on Driver Characteristics

The “white hole effect” alters the driving environment during a tunnel’s exit phase, making it more difficult and uncertain for drivers to access information and control their behavior, thereby endangering traffic safety. Consequently, the driving risk at the exit of a long spiral tunnel served as the subject of this study, and the Jinjiazhuang spiral tunnel served as the object of the natural vehicle driving experiment. Following the theory of a non-linear autoregressive dynamic neural network, a vehicle speed prediction model based on driver characteristics was developed for the exit phase of the tunnel, taking driver expectations and behavioral changes into account. It also classifies the driver’s behavior during the tunnel’s exit phase to assess the risk posed by the driver’s behavior during the tunnel’s exit phase and determine a dynamic and safe comfort speed. The study’s results indicate that the driver’s behavioral load changed significantly as the vehicle approached the tunnel exit. At the exit of the spiral tunnel, the vehicle’s actual speed was 71 km/h, which is below the speed limit of 80 km/h. This demonstrates that the expected change in the driver’s behavior in the tunnel exit phase was substantial. Therefore, setting the emotional safety and comfort speed so that the driver maintains a smooth comfort level in the tunnel exit phase can reduce the tunnel exit driving risk. The results of this study provide a benchmark for tunnel traffic safety and lay the groundwork for further development of vehicle risk warning settings for the tunnel’s exit phase.

Effects of Polydextrose on Rheological and Fermentation Properties of Frozen Dough and Quality of Chinese Steamed Bread

AbstractThis study investigates the effects of polydextrose on the rheological and fermentation properties of frozen dough and the quality of Chinese steamed bread (CSB). Dough is frozen by spiral tunnel freezing and stored at −18 °C for 49 days, and CSB is produced using the frozen dough. Results show that the gas producing capacity, gas holding capacity, and viscoelasticity of the frozen dough decrease as the frozen storage time progresses. However, these properties improve in the frozen dough added with polydextrose. Differential scanning calorimetric analysis shows that the melting enthalpy (ΔHm) of the frozen dough enhanced after storage. By contrast, the ΔHm of the frozen dough added with polydextrose decreases after storage, indicating high water holding capacity and homogeneous, small ice crystal structure of the frozen dough. Moreover, the addition of polydextrose reduces the hardness and porosity of CSB, which improves the quality of the bread. Thus, adding polydextrose can improve the rheological and fermentation properties of frozen dough and the quality of CSB.

Smoke propagation characteristics and influencing factors of high-temperature spiral tunnel fire

Abstract A tunnel fire may cause great damage to people, vehicles, facilities and tunnel structures if it is not effectively controlled. Therefore, it is very important to clarify the smoke propagation characteristics and influencing factors that can help to accelerate the removal of fire smoke and reduce casualties and property losses. In order to study the influence of slope, curvature radius and ambient temperature on smoke propagation during the tunnel operation period, based on the high-temperature spiral tunnel in Midi village, Yunnan Province, the internal and external environmental parameters of the tunnel were measured on site and the numerical simulation model was established by using the simulation software FDS, and the control variable method was used to study the fire smoke propagation characteristics of the tunnel with different characteristics. The results show that: the influence of slope on smoke migration velocity is non-linear, the greater the slope is, the greater the change of smoke spreading speed is; the smaller the curvature radius is, the greater the obstruction to smoke migration is, and the slower the smoke migration speed is; high temperature speeds up the smoke exhaust rate in the tunnel but has less promotion of the fire smoke migration.

Influence of Ventilation Duct Parameter Optimization on Pollutant Diffusion in Spiral Tunnels

The spiral tunnel could flexibly design the curvature and slope of the tunnel according to the geological structure, avoiding the adverse effect of complex terrain and topography, and had a strong advantage in engineering applications. Different from ordinary straight linear tunnels, spiral tunnels have a circular trend with obvious curvature and slope, which ensures certain differences between construction ventilation of the two types of tunnels, especially in terms of ventilation air flow field and pollutant diffusion. Relying on the actual spiral tunnel project, this paper studies the diffusion mechanism of ventilation pollutants in spiral tunnel construction. Optimization of the layout of the air duct based on numerical simulation and proposed pulsating ventilation method was performed to improve the ventilation and drainage effect of the tunnel. The time to reach the carbon monoxide concentration after blasting, and the dust concentration during the spraying process, were determined as indicators to measure the ventilation effect during the construction period. The hanging position of the air duct, the distance from the air duct outlet to the palm face, and the air speed were determined as the main factors affecting the ventilation effect. The main factors, the degree of influence and sensitivity of each influencing factor on the index, are studied, and the optimal air duct layout scheme suitable for the site is determined. The scheme can improve the ventilation effect and ventilation quality and provide effective reference for ventilation problems during the construction of other spiral tunnels. Meanwhile, more factors need to be examined to study the impact of pollutants in spiral tunnel construction, and physical models are needed to study the diffusion mechanism of pollutants in a spiral tunnel.

Influence of traffic on the temperature field of tunnel in cold region: A case study on the world's longest highway spiral tunnel

The impact of the piston wind caused by vehicle traffic on the temperature field distribution of the tunnel cannot be ignored, especially in spiral tunnels, where the temperature field distribution is more complicated than that in straight tunnels. Based on the world's longest highway spiral tunnel, this study explores the influence of traffic on the temperature fields of spiral and straight tunnels, and proposes a new design method for laying length of insulation layer. The results show that traffic has a significant effect on the temperature field distribution in the tunnel. The influence degree of different traffic elements decreases in the following order: average vehicle speed > daily traffic > morning rush hour > evening rush hour. The temperature field distribution of spiral tunnels is asymmetry on the left and right compared with straight tunnels, while the influence degree of traffic on the outside of spiral tunnels is similar to that of straight tunnels. Due to the difference of wind direction and traffic direction at different tunnel openings, an asymmetric insulation layer laying method is proposed. It is suggested that the lengths of the insulation layers of the Jinjiazhuang Tunnel should be 1200 m for the right tunnel inlet, 700 m for the right tunnel outlet, 700 m for the left tunnel inlet, and 1400 m for the left tunnel outlet.

Quality of frozen mackerel during storage as processed by different freezing methods

ABSTRACT The fresh mackerel was frozen using four different quick-freezing methods, such as refrigerator freezing, quick freezer freezing, spiral tunnel freezing and plate freezing. Water retention, color, texture, electrical conductivity, total volatile base nitrogen (TVB-N), K value, malondialdehyde (MDA), sulfhydryl group and protein secondary structure were used as physicochemical indicators to evaluate the changes in fish quality, and water migration in the fish was observed by low field NMR. The results showed that the mackerel treated with spiral tunnel freezing method was the closest to the fresh samples, with the best water retention capacity during freezing, slow decrease in hardness and elasticity, low rate of increase in conductivity values, TVB-N content, MDA content and K value, slow decrease in total sulfhydryl content, and more stable protein secondary structure. This indicated that fat oxidation was the lowest and protein degradation was the least, which effectively maintained the moisture and freshness of the samples and was the most favorable treatment to maintain the quality of mackerel compared with other groups.

A Comparative Study of Different Freezing Methods on Water Distribution, Retrogradation, and Digestion Properties of Liangpi (Starch Gel Food)

AbstractIn this work, the effects of refrigerator freezing method (RF), spiral tunnel freezing method (SF), and liquid nitrogen spray freezing method (LF) on water distribution, microstructure, retrogradation, and digestion properties of Liangpi are investigated. Results from SEM and water distribution show the starch gel structure of Liangpi after LF treatment is more continuous, and its A21 content is higher, which are closer to fresh Liangpi, followed by SF and RF. XRD and FT‐IR data indicate that as the freezing rate increases, the relative crystallinity and R1047/1022 value of the samples decrease. This is consistent with the data obtained from texture properties. Texture properties of samples treat by LF and SF are closer to fresh Liangpi, especially the hardness index. The in vitro digestibility of Liangpi also shows the same trend. Therefore, the freezing method with a faster rate could inhibit the starch gel retrogradation, improve the texture properties of Liangpi, and guarantee the quality of Liangpi. However, considering the economics of enterprise production, the spiral tunnel freezing method is more suitable for the actual production of frozen Liangpi. The data obtained provide a theoretical guidance for the actual production of frozen Liangpi.

Research on the Driving Load of Spiral Tunnels

Research on the Driving Load of Spiral Tunnels

Influence of three types of freezing methods on physicochemical properties and digestibility of starch in frozen unfermented dough

Three types of freezing methods, namely, spiral tunnel freezing method (SF), cryogenic refrigerator freezing method (RF) and liquid nitrogen spray freezing method (LF), were applied to frozen unfermented dough. The particle size distribution and SEM results showed freezing methods reduced the average particle size of starch granules and destroyed the surface microstructure, especially RF, and the damaged starch content and swelling power of starch after treatment increased. Gelatinization and pasting properties of starches changed to varying degrees, indicating freezing methods caused the internal rearrangement of starch molecules. This view could also be inferred from X-ray diffraction (XRD) and Fourier Transform infrared spectroscopy (FT-IR) data. The relative crystallinity (35.51%–38.56%) and the R1047/1022 (0.562–0.590) were increased, compared with the control (32.44%, 0.559, respectively). Meanwhile, freezing treatment improved the digestibility of starch by promoting the combination of enzymes and starch, especially RF. Larger ice crystals formed by RF with slower freezing rate produced larger damage to starch structure, more likely to promote the binding with enzymes. LF with faster freezing rate had less effect on the starch composition than RF and SF with slower freezing rate. The data obtained clarified the influence of freezing methods on the structure and properties of starch in a yeast-free dough system, and enriched the knowledge regarding the effect of freezing technology on food components.

Study on the influence of radius of curvature on flow resistance in spiral pipe

With the continuous development of west of China, a new kind of tunnel, namely spiral tunnel, has appeared in the expressway. Due to the special linear pattern, the resistance of airflow in spiral tunnel has been found to change, but there are few relevant researches at present. Therefore, numerical calculation method is used to study the variation of flow resistance in spiral pipe with different curvature. The results show that when the fluid flows in the spiral pipe, the wind speed is not uniformly distributed. The highest speed is not in the center of the pipe, but on the outside of the pipe, and the offset distance decreases with the increase of the radius of curvature. In addition, the change of flow resistance in spiral pipe is studied, and it is found that the change rate of flow resistance decreases with the increase of curvature radius. It shows that the radius of curvature is negatively correlated with the flow resistance.

Dynamic Response and Perturbation Design of Surrounding Rock in Blasting Construction of Small Radius Spiral Tunnel

To achieve a better blasting effect of ultra-long and deep buried spiral tunnel with a small radius, it is necessary to study the dynamic response and disturbance of blasting construction. As the engineering background with a poor engineering geological condition, this paper uses the Midi spiral-tunnel in Yunnan province that has a small radius of curvature, a large burial depth, and a large excavation distance. The blasting load is determined first by calculation. Under different blasting construction parameters, the deformation and dynamic vibration responses of the surrounding rocks are studied using the finite element numerical method. The damage mechanism of rock under the blasting load is analyzed. The tunnel engineering blasting is designed and calculated, and the small distance disturbance design of spiral tunnel blasting construction with a small radius is performed from the excavation method and blasting parameters. The results serve as a reference to reveal the surrounding rock dynamics in blasting construction of the spiral tunnel with a small radius.

Effect of the Double‐Line Spiral Tunnel Curvature on the Tunnel Construction Stability

In the construction of mountain highway, in order to avoid complicated geology and adapt to the requirements of the terrain of the large height difference and the large slope, the double‐line spiral tunnels are gradually applied. The purpose of this paper is to analyze the mechanical behavior of the double‐line spiral tunnel and its surrounding rock under different line curvatures, and to obtain the influence of the curvature of the spiral tunnel on the stability of the double‐line tunnel construction. The analysis of this paper is based on the engineering background of double‐line spiral tunnels in China’s Yunnan province. The elastoplastic three‐dimensional rock strata‐tunnel by means of finite difference FLAC3D software was established to simulate the construction process. The model was verified by comparing the calculation results and the actual monitoring data of tunnel vault settlement. The small curvature radius spiral makes the mechanical behavior of the double‐line tunnel uneven and the surrounding rock deformed unevenly. A quantitative analysis and qualitative evaluation of the influence of curvature radius were established by the systematic evaluation index of (1) ratio of compressive stress on both sides of the tunnel, (2) stress ratio of double‐line tunnel, (3) convergent deformation of the cross section of the tunnel, and (4) deformation of the surrounding rock on the top of the tunnel. The results show that the small curvature radius (less than 200 m) will make the inner pressure of the inner tunnel significantly greater than the external pressure stress, showing obvious asymmetry, and the inner tunnel vault tensile stress is greater than the outer tunnel. With the increase of the curvature radius (about more than 400 m), the ratio of the compressive stress on the inside and outside of the tunnel tends to be constant, and the bias condition is weakened and stabilized. Meanwhile, the smaller curvature radius makes the convergent deformation of the cross section of the tunnel appear asymmetrical, and the compression quantity inside the tunnel center line is larger. It provides a reference basis for the stability control of the construction of the double‐line spiral tunnels in the mountainous area.

Optimization measurements on feeding machines with automated control system for aquaculture

This paper discusses about the measurement of optimization on feeder machine with automatic system control for aquaculture. This paper mainly aims to observe four main parts of feeding machine of aquaculture: major inlet, scale system, spiral tunnel, and throwing system. The observation done includes the energy of electricity usage of each unit of feeding weight which is processed, duration of process of each part, the exchange of rotor speeds, and the flow of feeding speed rate in gram per second. In this research, the design of feeding machine with automatic system based on Arduino Uno is conveyed. The feeds size used in this research are 2mm and 4mm. The measurement of optimization aims to consider the weight of the feeds, and the system of machine that works optimally. The result from experiment releases that the machine designed is able to work optimally on 2kg feeds of each process in 70 seconds and 71 seconds, and 0.085Wh on energy of electricity usage.

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

. 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.

Improving the organism's resistance to the stress “time deficiency” by iodine-containing thyroid hormones

The high prevalence of diseases of stressful etiology and insufficient knowledge of the mechanisms of their pathogenesis, as well as factors limiting the intensity of the stress reaction, among which iodine-containing thyroid hormones have recently been studied, determine the relevance of the study. The purpose of the work is to study the effect of thyroid status on the organism's resistance to emotional stress. The experiment was performed on 180 white male rats weighing 220–240 g. Stress was modeled according to the “time deficiency” method, when the animal, trying to avoid contact with water quickly filling the spiral tunnel, was forced to move up. Statistical processing of the obtained results was carried out using generally accepted medical statistics methods using program “Statistica 10.0”. The introduction of mercazolyl (25 mg / kg for 20 days), which determines a lower concentration of iodine-containing thyroid hormones in the blood under stress, prevents an increase in the relative weight of the adrenal glands and the corticosteroids level in the blood, an increase in physical endurance and horizontal motor activity of animals, inhibits their research behavior, and aggravates damage gastric mucosa in these conditions. The introduction of L-thyroxine in small doses (1.5-3 μg / kg 28 days) provides a higher level of iodine-containing thyroid hormones and increases the body's resistance to stress (limits the changes in the relative weight of the adrenal glands, spleen and thymus, corticosteroids and insulin levels in the blood , behavior and physical endurance of animals, damage to the gastric mucosa). Iodine-containing thyroid hormones increase the body's resistance to stress of the “time deficiency”, which proves their important role in the body's anti-stress system.

Simulation and Experimental Studies on Grain Selection and Structure Design of the Spiral Selector for Casting Single Crystal Ni-Based Superalloy

Grain selection is an important process in single crystal turbine blades manufacturing. Selector structure is a control factor of grain selection, as well as directional solidification (DS). In this study, the grain selection and structure design of the spiral selector were investigated through experimentation and simulation. A heat transfer model and a 3D microstructure growth model were established based on the Cellular automaton-Finite difference (CA-FD) method for the grain selector. Consequently, the temperature field, the microstructure and the grain orientation distribution were simulated and further verified. The average error of the temperature result was less than 1.5%. The grain selection mechanisms were further analyzed and validated through simulations. The structural design specifications of the selector were suggested based on the two grain selection effects. The structural parameters of the spiral selector, namely, the spiral tunnel diameter (dw), the spiral pitch (hb) and the spiral diameter (hs), were studied and the design criteria of these parameters were proposed. The experimental and simulation results demonstrated that the improved selector could accurately and efficiently produce a single crystal structure.