• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.7 no.2
• /
• pp.51-59
• /
• 2011

Storage and transfer heat in soils are governed by the soil thermal properties and these properties are therefore needed in many engineering applications, including horizontal ground heat exchanger for ground-coupled heat pumps. This paper presents the measured results of the thermal diffusivity of soils(silica, quartzite, limestone, sandstone, and masonry soils) used for the trench backfilling materials of the horizontal ground heat exchanger. To assess this thermal property, we (i) measure the soil thermal conductivities and volumetric heat capacities using dual-probe method and (ii) compare the estimates from the de Vries method of summing the heat capacities of the soil constituents. The results show that the thermal diffusivity tends to increase as dry soil begins to wet, but it approaches a constant value or even decreases as the soil continues to wet. Measurements made by using the dual-probe method agreed well with independent estimates obtained using the single-probe method.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05a
• /
• pp.230-233
• /
• 2006

Conventionally, it used to be focused on simply prevention of further settlement of structures, where, much of problems were raised and sometimes the construction itself was not possible. Further, rough estimation of the ground, which is unseen, often incurred many troubles in the maintenance. D-ROG method is a high-tech technology that changes almost all of the concepts on the conventional grouting, is expanding its application scope spanning from the restoration of settled structures to ground strengthening works necessary for building enlargement and remodeling.

• Smart Structures and Systems
• /
• v.16 no.6
• /
• pp.981-1002
• /
• 2015

For vibration control of civil structures, especially large civil structures, one of the important issues is how to place a minimal number of actuators and sensors at their respective optimal locations to achieve the predetermined control performance. In this paper, a methodology is presented for the determination of the minimal number and optimal location of actuators and sensors for vibration control of building structures under earthquake excitation. In the proposed methodology, the number and location of the actuators are first determined in terms of the sequence of performance index increments and the predetermined control performance. A multi-scale response reconstruction method is then extended to the controlled building structure for the determination of the minimal number and optimal placement of sensors with the objective that the reconstructed structural responses can be used as feedbacks for the vibration control while the predetermined control performance can be maintained. The feasibility and accuracy of the proposed methodology are finally investigated numerically through a 20-story shear building structure under the El-Centro ground excitation and the Kobe ground excitation. The numerical results show that with the limited number of sensors and actuators at their optimal locations, the predetermined control performance of the building structure can be achieved.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2008.11a
• /
• pp.135-139
• /
• 2008

For deep basement construction of buildings downtown, the usage of Top-Down Method is increasing as much as ever from strong demand. One of the essential elements for the construction by Top Down Method is the pre-founded columns, which are installed in the ground and on which a building is installed. The fact that the pre-founded columns are placed in the ground makes them susceptible to its plumbness; this aspect distinguishes pre-founded columns from general columns. However, there are no criteria for erection tolerance. Therefore, field-measured-data concerning out-of-plumb of pre-founded columns in the construction field should be accumulated and investigated so that criteria and specifications for the erection tolerance of pre-founded columns may be established through the understanding of its aspects. In this paper, we investigate out-of-plumb of pre-founded columns for the construction case and analyze its aspects, and propose considerations for design and construction phase.

• Proceedings of the KIEE Conference
• /
• 2009.04a
• /
• pp.6-9
• /
• 2009

Recently, there have been studied the importance of the grounding system, as electrical equipments installed in the building, such as intelligent building. The object of grounding of electrical facilities is to protect human and machine damage from the power supply interruption high voltage by use of the accident current dissipating into the ground. In this paper, we is proposed to design of grounding system with economical efficiency in electric rolling stocks facilities. To make efficient ground, ground potential rise must be controlled in the way of overall lowering and evenness instead of independent grounding method with respect to electrical facilities.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.118-119
• /
• 2017

In the S.C.W (soil cement wall) grouting solution, Cement grout ratio of 1 part Portland cement and 1part water is being used. However, Co₂ and harmful heavy metals such as cr6+ are discharged in the process, causing a serious environmental issue. The purpose of the present study is therefore to substitute cement grout to inorganic binder and identify durability properties of ground solidification materials.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.4_2
• /
• pp.687-696
• /
• 2023

In recent construction sites, digital maps obtained through drone photogrammetry have garnered increasing attention as indispensable tools for effective construction site management. the strategic placement of Ground Control Points (GCPs) is crucial in drone photogrammetry. Nevertheless, the manual labor and time-intensive nature of GCP surveying pose significant challenges. The purpose of this study is to design the concept of automated GCPs survey technology for enhancing drone photogrammetry efficiency in construction sites. As a result, the productivity of the automated method was analyzed as 118,894.7㎡/hr. It is over 25% productivity improvement compared to traditional methods. In future studies, economic analysis of automated methods should be studied.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2009.05b
• /
• pp.213-217
• /
• 2009

Underground structures are built into concrete like a architecture and public works. Concrete has watertightness as such, But buildings are leaking from the cracks. Recently, construction method do a lot of close construction in the downtown area. So architects are using the method for the outer layer of a two-layer wall to save spaces. They have been using Top-down method and waterproof agent method and others to outer layer of a two-layer wall method. But, There are many leakage in underground structure from lack on requirements performance of materials. Therefore, I hope to test the outside Waterproof Method of Ground using Wire-mesh and Non-hardening Viscosity Waterproof. In addition to, I wish to apply as outside waterproof method for the section for the outer layer of a two-layer wall in underground structure.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.05a
• /
• pp.875-878
• /
• 2006

In the case of a vibration sensitive equipment, it require a vibration free environment to provide its proper function, therefore, it is very important to predict precisely vibration environment of microelectronics production facility due to adjacent blast work. However, it is not easy to evaluate a quantitative vibration response of structure due blast because it can be determined by the characteristics of vibration sources, propagation through rock and soil and dynamic properties of building. In this paper, vibration influence evaluation of micro-electronic Production building induced from adjacent blast activity was performed by real measurement data obtained on ground and structure at same time. And blast vibration allowable limit on ground was supposed by measurement data analysis in order to avoid operation error of precision equipments

• Journal of the Korea Institute of Building Construction
• /
• v.15 no.6
• /
• pp.631-639
• /
• 2015

In the unit modular construction, the unit module prefabricated in a factory with a high level of accuracy does not fit completely onto the ground-joint junction due to the low accuracy of the ground work. This difference in the level of accuracy can cause diverse problems, such as twisting the upper unit modules and loosening the connection between the module and the footing. On this background, the aim of this study is to develop a technique for adjusting the height of the prefabricated individual footing. To accomplish the aim, a height adjustment method using bolts and nuts is proposed, and a shop drawing and the construction sequence are also presented in this study. The structural safety is verified through a structure simulation. In the future, research will be conducted on a mock-up test of the height adjustment method developed in this study, and an analysis of economic feasibility will be performed in order to verify its constructability and usability.