• Wind and Structures
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• v.32 no.2
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• pp.127-142
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• 2021

Wind load acting on a standalone structure is different from that acting on a similar structure which is surrounded by other structures in close proximity. The presence of other structures in the surrounding can change the wind flow regime around the principal structure and thus causing variation in wind loads compared to a standalone case. This variation on wind loads termed as interference effect depends on several factors like terrain category, geometry of the structure, orientation, wind incident angle, interfering distances etc., In the present study, a three building configuration is considered and the mean pressure coefficients on each face of principle building are determined in presence of two interfering buildings. Generally, wind loads on interfering buildings are determined from wind tunnel experiments. Computational fluid dynamic studies are being increasingly used to determine the wind loads recently. Whereas, wind tunnel tests are very expensive, the CFD simulation requires high computational cost and time. In this scenario, Artificial Neural Network (ANN) technique and Support Vector Regression (SVR) can be explored as alternative tools to study wind loads on structures. The present study uses these data-driven approaches to predict mean pressure coefficients on each face of principle building. Three typical arrangements of three building configuration viz. L shape, V shape and mirror of L shape arrangement are considered with varying interfering distances and wind incidence angles. Mean pressure coefficients (Cp mean) are predicted for 45 degrees wind incidence angle through ANN and SVR. Further, the critical faces of principal building, critical interfering distances and building arrangement which are more prone to wind loads are identified through this study. Among three types of building arrangements considered, a maximum of 3.9 times reduction in Cp mean values are noticed under Case B (V shape) building arrangement with 2.5B interfering distance. Effect of interfering distance and building arrangement on suction pressure on building faces has also been studied. Accordingly, Case C (mirror of L shape) building arrangement at a wind angle of 45º shows less suction pressure. Through this study, it was also observed that the increase of interfering distance may increase the suction pressure for all the cases of building configurations considered.

• Explosives and Blasting
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• v.31 no.2
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• pp.25-31
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• 2013

In this case of "Seongnam~Yeoju double-lanes railroad construction", there were resident houses and gas pipe which were concerned about damages from vibration and noise. Especially, gas pipe which is a diameter of ${\varphi}500mm$ was located under the ground along upside road. The limit of vibration was 1.0cm/sec to protect gas pipe. The electronic blasting systems have been used to control vibration & noise not only gas pipe but also resident houses. The results of tunnelling were successfully conducted with effective vibration control and quick excavation by electronic blasting without any damages to adjacent facilities.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.470-473
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• 2000

Because of the continuous growth of energy consumption, and also the tendency to site power lines and pipelines along the same routes, the close proximity of high voltage structures and metallic pipelines has become more and more frequent. Moreover, normal steady state and fault currents become higher as electric networks increase in size and power. Therefore, there has been and still is a growing concern (safety of people marking contact with pipeline, risk of damage to the pipeline coating, the metal and equipment connected to pipeline. especially cathodic protection system) about possible hazards resulting from the influence of high voltage power system on metallic structures(gas pipeline, oil pipeline and water pipeline etc.). Therefore, we analyze the interference problems when the gas pipeline is buried with power cable in the same submarine tunnel. This paper present the results of the study about interference mechanism, AC corrosion, limitation of safety voltage and analysis of indiction voltage.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.3
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• pp.60-70
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• 1999

The longitudinal stability characteristics of a Wing-In-Ground Effect Craft are quite different from that of the conventional airplane due to the existence of force and moment derivatives with regard to height. This stability characteristics plays a great role in designing a safe and efficient WIG due to its potential danger in sea surface proximity. The static and dynamic stability criteria are derived from the motion equations of WIG in the framework of small disturbance theory and discussed in the paper. The static and dynamic stability analyses of a 20-passenger WIG are conducted based on the wind tunnel test data and the dynamic motion behaviors are investigated for the change of the design parameters. Finally, the flying quality of the 20-passenger WIG is analysed at the cruising condition according to the military regulations.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.5
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• pp.481-486
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• 2014

This study aims at enhancing the performance of file-referring octree, suggested by Han(2014), for efficiently querying huge 3D point clouds, acquired by the 3D terrestrial laser scanning. Han's method(2014) has revealed a problem of heavy declining in query speed, when if it was applied on a very long tunnel, which is the lengthy and narrow shaped anisometric structure. Hereupon, the shape of octree has been analyzed of its influence on the query efficiency with the testing method of generating an independent octree in each isometric subdivision of 3D object boundary. This method tested query speed and main memory usage against the conventional single octree method by capturing about 300 million points in a very long tunnel. Finally, the testing method resulted in which twice faster query speed is taking similar size of memory. It is also approved that the conclusive factor influencing the query speed is the destination level, but the query speed can still increase with more proximity to isometric bounding shape of octree. While an excessive unbalance of octree shape along each axis can heavily degrade the query speed, the improvement of octree shape can be more effectively enhancing the query speed than increasement of destination level.

• Tunnel and Underground Space
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• v.25 no.3
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• pp.221-230
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• 2015

This study examined and analyzed several mine management software programs developed in domestic and oversea countries. In the oversea countries, many companies have developed and commercialized mine management softwares such as Dispatch, $Cat^{(R)}$ $MineStar^{TM}$ and FARA. These softwares provide many functionalities including real-time machine tracking, machine assignment optimization, productivity management, equipment health monitoring and remote control. For the domestic cases, this study reviewed two software programs (i.e., GEMISIMS, Truck-Shovel fleet optimization) developed by several researchers because there is no mine management software currently commercialized in Korea. In addition, this paper reports the two cases at the Jwaneng mine in Botswana and at the Robinson mine in United States where mine management software programs are used to support mine operations.

• Wind and Structures
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• v.25 no.3
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• pp.233-259
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• 2017

Investigations on simulated near-surface atmospheric boundary layer (ABL) in an open-jet facility are carried out by conducting experimental tests on small-scale models of low-rise buildings. The objectives of the current study are: (1) to determine the optimal location of test buildings from the exit of the open-jet facility, and (2) to investigate the scale effect on the aerodynamic pressure characteristics. Based on the results, the newly built open-jet facility is well capable of producing mean wind speed and turbulence profiles representing open-terrain conditions. The results show that the proximity of the test model to the open-jet governs the length of the separation bubble as well as the peak roof pressures. However, test models placed at a horizontal distance of 2.5H (H is height of the wind field) from the exit of the open-jet, with a width that is half the width of the wind field and a length of 1H, have consistent mean and peak pressure coefficients when compared with available results from wind tunnel testing. In addition, testing models with as large as 16% blockage ratio is feasible within the open-jet facility. This reveals the importance of open-jet facilities as a robust tool to alleviate the scale restrictions involved in physical investigations of flow pattern around civil engineering structures. The results and findings of this study are useful for putting forward recommendations and guidelines for testing protocols at open-jet facilities, eventually helping the progress of enhanced standard provisions on the design of low-rise buildings for wind.

• Journal of the Korean Institute of Gas
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• v.4 no.3 s.11
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• pp.26-32
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• 2000

Because of the continuous growth of energy consumption, and also the tendency to site power lines and pipelines along the same routes, the close proximity of high voltage structures and metallic pipelines has become more and more frequent. Moreover, normal steady state and fault currents become higher as electric networks increase in size and power Therefore, there has been and still is a growing concern(safety of people marking contact with pipeline, risk of damage to the pipeline coating, the metal and equipment connected to pipeline, especially cathodic protection system) about possible hazards resulting from the influence of high voltage power system on metallic structures(gas pipeline, oil pipeline and water pipeline etc.). Therefore, we analyze the interference problems when the gas pipeline is buried with power cable in the same submarine tunnel. This paper present the results of the study about interference mechanism, AC corrosion limitation of safety voltage and analysis of induction voltage.