Laboratory Experimental Study on Influencing Factors of Drainage Pipe Crystallization in Highway Tunnel in Karst Area

The crystalline blockage of tunnel drainage pipes in a karst area seriously affects the normal operation of drainage system and buries hidden dangers for the normal operation of the tunnel. In order to obtain the influencing factors and laws of tunnel drainage pipe crystallization in a karst area, based on the field investigation of crystallization pipe plugging, the effects of groundwater velocity, drainage pipe diameter, drainage pipe material, and structure on the crystallization law of tunnel drainage pipe in karst area are studied by indoor model test. The results show that: (1) With the increase of drainage pipe diameter (20–32 mm), the crystallinity of drainage pipes first increases and then decreases. (2) With the increase of water velocity in the drainage pipe (22.0–63.5 cm·s−1), the crystallinity of the drainage pipes gradually decreases from 1.20 g to 0.70 g. (3) The crystallinity of existing material drainage pipe is: M3 (poly tetra fluoroethylene) > M2 (pentatricopeptide repeats) > M4 (high density polyethylene) > M1 (polyvinyl chloride); M8 (polyvinyl chloride + coil magnetic field) is used to change the crystallinity of drain pipe wall material. (4) When the groundwater flow rate is 34.5 cm·s−1, M1 (polyvinyl chloride) and M8 (polyvinyl chloride + coil magnetic field) can be selected for the tunnel drainage pipe. The research on the influencing factors of tunnel drainage pipe crystallization plugging fills a gap in the research of tunnel drainage pipe crystallization plugging. The research results can provide a basis for the prevention and treatment technology of tunnel drainage pipe crystallization plugging.

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Crystallization law of karst water in tunnel drainage system based on DBL theory

Open Physics ◽

10.1515/phys-2021-0029 ◽

2021 ◽

Vol 19 (1) ◽

pp. 241-255

Author(s):

YongDong Wang ◽

Yang Liu ◽

ChuFan Qi ◽

TianYue Zhou ◽

Ming Ye ◽

...

Keyword(s):

Flow Rate ◽

Pipe Wall ◽

Functional Model ◽

Drainage System ◽

Crystallization Rate ◽

Normal Operation ◽

Karst Area ◽

Karst Water ◽

Flow State ◽

Drainage Pipe

Abstract When a tunnel is constructed in a karst area, crystallization of the drainage pipe caused by karst water often threatens the normal operation of the tunnel. This work contributes to this field of research by proposing a functional model based on the diffusion boundary layer (DBL) theory proposed by Dreybrodt in the 1990s. The model is formed by determining the flow rate distribution of the drainage pipe in a laminar flow state and turbulent state, and then by applying Fick’s diffusion law and Skelland’s approximate formula. Then, to further verify the applicability of the functional model, a model test was carried out in the laboratory and the test results are compared to the theoretical results. The results show that the crystallization rate of karst water is mainly affected by the roughness of the pipe wall, followed by the slope of pipes. The slope can affect flow state by controlling the flow rate, which in turn affects the crystallization rate of karst water. When the slope of the drainage pipe is 3, 4, and 5%, the error between the experimental results and the theoretical calculation results is 24.7, 8.07, and 27.9%, respectively, and when the liquid level in the pipe is 7.2, 10.2, and 13.3 mm, the error is 27.9, 9.82, and 2.07%, respectively. Considering that the flow will take away the crystalline deposits on the pipe wall in the experiment, although some results have certain errors, they do not affect the overall regularity.

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A Novel Impedance Micro-Sensor for Metal Debris Monitoring of Hydraulic Oil

Micromachines ◽

10.3390/mi12020150 ◽

2021 ◽

Vol 12 (2) ◽

pp. 150

Author(s):

Hongpeng Zhang ◽

Haotian Shi ◽

Wei Li ◽

Laihao Ma ◽

Xupeng Zhao ◽

...

Keyword(s):

Magnetic Field ◽

Wear Debris ◽

Detection Method ◽

Silicon Steel ◽

Detection Sensitivity ◽

Normal Operation ◽

Metal Debris ◽

Hydraulic Oil ◽

Steel Strips ◽

The Magnetic Field

Hydraulic oil is the key medium for the normal operation of hydraulic machinery, which carries various wear debris. The information reflected by the wear debris can be used to predict the early failure of equipment and achieve predictive maintenance. In order to realize the real-time condition monitoring of hydraulic oil, an impedance debris sensor that can detect inductance and resistance parameters is designed and studied in this paper. The material and size of wear debris can be discriminated based on inductance-resistance detection method. Silicon steel strips and two rectangular channels are designed in the sensor. The silicon steel strips are used to enhance the magnetic field strength, and the double rectangular detection channels can make full use of the magnetic field distribution region, thereby improving the detection sensitivity and throughput of the sensor. The comparison experiment shows that the coils in series are more suitable for the monitoring of wear debris. By comparing and analyzing the direction and the presence or absence of the signal pulses, the debris sensor can detect and distinguish 46 µm iron particles and 110 µm copper particles. This impedance detection method provides a new technical support for the high-precision distinguishing measurement of metal debris. The sensor can not only be used for oil detection in the laboratory, but also can be made into portable oil detection device for machinery health monitoring.

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Influencing factors on transfer and bioaccumulation of soil cadmium and assessment of its environmental risk in a typical karst area, China

Chemistry and Ecology ◽

10.1080/02757540.2021.1886282 ◽

2021 ◽

pp. 1-15

Author(s):

Shiqi Tang ◽

Xiujin Liu ◽

Min Peng ◽

Zheng Yang ◽

Honghong Ma ◽

...

Keyword(s):

Influencing Factors ◽

Environmental Risk ◽

Karst Area ◽

Soil Cadmium

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Influencing Factors and Evaluation Indexes of the Stress of Bridge Pile Foundation in Karst Area

Proceedings of the 6th International Conference on Information Engineering for Mechanics and Materials ◽

10.2991/icimm-16.2016.92 ◽

2016 ◽

Author(s):

Jian Xing ◽

Xichang Xu ◽

Lingfa Jiang

Keyword(s):

Influencing Factors ◽

Pile Foundation ◽

Karst Area ◽

Evaluation Indexes ◽

Bridge Pile Foundation

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Tobit model-based analysis on the influencing factors of wheat loss during harvesting by the combine harvester

Journal of Computational Methods in Sciences and Engineering ◽

10.3233/jcm-215755 ◽

2021 ◽

pp. 1-14

Author(s):

Hong Ji ◽

Xun He ◽

Li Ding ◽

Zhe Qu ◽

Wenkang Huang ◽

...

Keyword(s):

Regression Model ◽

Influencing Factors ◽

Loss Rate ◽

Henan Province ◽

Normal Operation ◽

Tobit Regression ◽

Wheat Field ◽

Combine Harvester ◽

Main Factors ◽

Tobit Regression Model

Based on the investigation data of wheat mechanized harvest in eight major wheat producing areas from the south to the north of Henan Province, the main factors affecting wheat mechanized harvest loss were identified and the influence of each factor was decomposed. In this article, the loss rate of wheat mechanical harvest was calculated by using the method of artificial measurement of wheat yield in the field, and the influencing factors of wheat mechanical harvest operation in 8 regions of Henan province were treated and analyzed by using Tobit regression model. In this paper, the loss rate of wheat mechanical harvest was calculated by using the method of wheat field artificial yield measurement and the influencing factors of wheat mechanical harvest operation in eight regions of Henan province were treated and analyzed by using Tobit regression model. The results show that the average harvest loss rate in the field amounts to 2.96%, the average harvest loss rate at the edge of field amounts to 3.06%, whereas the loss rate in the normal operation area amounts 2.86%. The main factors that caused the harvest loss of wheat field machinery were the maturity of wheat, the area of operation field, the diseases and pests, weather conditions and the accumulated working hours of harvester drivers in a single day. Therefore, the main technical measures to reduce the operation loss of wheat combine harvester were put forward to provide a theoretical basis for promoting the deep integration of agricultural machinery and agronomy.

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A Case Study of Gas Leakage and Assessment of Mechanical Properties With Welding Variables in Fillet Weldment of Small Diameter Pipe

Volume 3: Materials and Joining; Pipeline Automation and Measurement; Risk and Reliability, Parts A and B ◽

10.1115/ipc2006-10102 ◽

2006 ◽

Author(s):

Jong-Hyun Baek ◽

Woo-Sik Kim

Keyword(s):

Mechanical Properties ◽

Fatigue Strength ◽

Natural Gas ◽

Weld Zone ◽

Branch Pipe ◽

Small Diameter ◽

Welding Process ◽

Pipe Diameter ◽

Pipe Material ◽

Gas Leakage

A branched pipe joint has been employed to execute the pressure control, condition check, purgation, and distribution of the gas in the natural gas facilities. Installation of branch pipes is generally done through the welding work, and as a welding process, the weldolet and the sockolet are used. During the maintenance working of in-service natural gas pipeline, there was gas leakage in sockolet weldment. The causes of incident were investigated with various tests. We found the wrong pipe material, the weld defect and the non-destructive test limitation of fillet weldment as the reasons of gas leakage. As the follow-up measures, it was done to assess the soundness depending upon the configuration of the weld zone, a change in the welding process and a change in the pipe diameter by assessing the mechanical properties of the sockolet weld zone and further to assess comparatively the mechanical performance of the sockolet weld zone and that of the weldolet weld zone. In the sockolet weld, the tensile strength showed no difference and the fatigue strength showed a difference depending upon a change in the welding process. In the case that the leg length of the weld zone was made lengthwise in the direction of the branch pipe, the SMAW welding work compare with the GTAW, the sectional area of the weld zone was more increased, and the pipe diameter was more increased, the fatigue strength was increased.

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The Influencing Factors on the Axial Magnetic Field Distribution Characteristics of GMA

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.139-141.801 ◽

2010 ◽

Vol 139-141 ◽

pp. 801-804

Author(s):

Xiao Yang Jiang ◽

Quan Guo Lu ◽

Ding Fang Chen ◽

Meng Lun Tao ◽

Min Zhou

Keyword(s):

Magnetic Field ◽

Influencing Factors ◽

Field Distribution ◽

Optimization Design ◽

Axial Magnetic Field ◽

Magnetic Field Distribution ◽

Distribution Characteristics ◽

Output Performance ◽

Magnetostrictive Actuator ◽

Bottom Cover

. A direct aspect of influencing giant magnetostrictive actuator's output performance is the driving magnetic field characteristics. Therefore, research on the influencing factors on the axial magnetic field distribution characteristics of giant magnetostrictive actuator is of great significance in the design. This paper analyzes the importance of the axial magnetic field distribution characteristics, analyzes the driving magnetic field using finite element method based on a designed giant magnetostrictive actuator, studies the affections of coil height, coil shape , magnetic block material, shell material , skeleton material, bottom cover material and output shaft material on the axial magnetic field distribution characteristics and reaches some conclusions about the influencing factors on the axial magnetic field distribution characteristics of giant magnetostrictive actuator. According to this paper, it provides the guidance for the optimization design of the driving magnetic field of the giant magnetostrictive actuator.

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Assessment the Influencing Factors on MRS Signal Obtained from High Magnetic Field Strength (1.5T) MRI Scanners During the Application of Homemade Metabolite Phantom

Journal of Magnetics ◽

10.4283/jmag.2019.24.1.090 ◽

2019 ◽

Vol 24 (1) ◽

pp. 90-98 ◽

Cited By ~ 2

Author(s):

Mahdi Saeedi-Moghadam ◽

Majid Pouladian ◽

Mehrzad Lotfi ◽

Reza Faghihi

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Magnetic Field Strength ◽

Influencing Factors ◽

High Magnetic Field ◽

High Magnetic Field Strength

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Forestland change and soil erosion in karst watershed under the Grain to Green Project

10.5194/egusphere-egu2020-4456 ◽

2020 ◽

Author(s):

Siwen Feng ◽

Hongya Wang ◽

Hongyan Liu ◽

Chenyi Zhu ◽

Shuai Li

Keyword(s):

Soil Erosion ◽

Influencing Factors ◽

Southwest China ◽

Drainage Basin ◽

Karst Area ◽

Karst Region ◽

Vegetation Growth ◽

The Past ◽

Pixel Scale ◽

River Drainage Basin

<div>With the implementation of the Grain to Green Project, the vegetation growth in karst region in southwest China has increased. In order to explore whether the growth of trees can be sustained after artificial afforestation in karst area and the influence of the forestland change on soil erosion, the WaTEM/SEDEM model was used to simulate the 11 stages of annual soil erosion in the past 33 years in Chongan river drainage basin in Guizhou, and the dominant influencing factors of soil erosion change in the past 33 years were discussed based the pixel scale in this study. The results showed that the forestland increased in a fluctuating way after the conversion project, and the decrease of forestland was mainly caused by drought, especially in the area where the dolomites were distributed. Therefore, the change of forestland caused no significant improvement in soil erosion since the Grain to Green Project.</div><p></p>

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