• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.9-13
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• 2009

Recently, construction in downtown is often done closely at the adjacent building. In this case, underground construction need to Basement Composite Wall(BCW) construction. However, generally, during the construction process of BCW form works have many problems that are narrow working space and inefficient time consuming. Despite of these problems, there was no quantitative research for the work time of BCM assembly. Therefore, in this study, work time of CBW form assembly in underground construction is identified by the work analysis. The results of this study reveal that buttress work of basement form take lots of time in the entire work process of Basement Composite Wall form assembly.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.2
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• pp.145-153
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• 2020

The purpose of this study is to investigate the effects of composition of underground structural wall and H-pile in soil cement. The results of previous experimental studies are re-analyzed and the nonlinear cross-sectional analyses of composite basement walls are performed to verify their nonlinear flexural behavior. Based on the study, it is explained how the gap deformation between H-Pile and RC wall should be considered in the design of flexure of composite underground walls. The nonlinear cross-sectional analysis shows that the load-displacement curves of composite basement wall specimens exhibiting flexural behavior exist between the results of the analysis of the complete and non-composite cases. When predicting the behavior of the composite basement wall by nonlinear cross-sectional analysis, the flexural behavior of the composite basement wall could be suitably predicted by considering the reduction of the composite ratio due to tensile stress acting on shear connectors.

• Geomechanics and Engineering
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• v.36 no.6
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• pp.563-573
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• 2024

In this study, various countermeasures used to mitigate tunnel deformations due to nearby multi-propped basement excavation in soft clay are explored by three-dimensional numerical analyses. Field measurements are used to calibrate the numerical model and model parameters. Since concrete slabs can constrain soil and retaining wall movements, tunnel movements reach the maximum value when soils are excavated to the formation level of basement. Deformation shapes of an existing tunnel due to adjacent basement excavation are greatly affected by relative position between tunnel and basement. When the tunnel is located above or far below the formation level of basement, it elongates downward-toward or upward-toward the basement, respectively. It is found that tunnel movements concentrate in a triangular zone with a width of 2 H_e (i.e., final excavation depth) and a depth of 1 D (i.e., tunnel diameter) above or 1 D below the formation level of basement. By increasing retaining wall thickness from 0.4 m to 0.9 m, tunnel movements decrease by up to 56.7%. Moreover, tunnel movements are reduced by up to 80.7% and 61.3%, respectively, when the entire depth and width of soil within basement are reinforced. Installation of isolation wall can greatly reduce tunnel movements due to adjacent basement excavation, especially for tunnel with a shallow burial depth. The effectiveness of isolation wall to reduce tunnel movement is negligible unless the wall reaches the level of tunnel invert.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.3
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• pp.159-165
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• 2002

Currently structural design of basement exterior wall is based on the assumption of boundary condition of plate, which may lead to erroneous results. In this study, the behavior of basement exterior wall subject to earth pressure and hydraulic pressure is investigated using linear finite element analysis. Parametric studies are conducted to investigate the variation of moment and shear force according to column-to-wall stiffness and aspect ratios. Using these numerical results, modification factors applicable to the design of basement exterior wall are presented. Design example is illustrated, showing satisfactory results.

• Journal of the Korean Society of Safety
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• v.17 no.3
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• pp.118-122
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• 2002

A numerical study using linear finite element analysis is performed to investigate the behavior of basement wall subject to soil and water pressure. Currently, structural design of basement wall is based on the assumption for boundary condition of plate, which may lead to the erroneous results. In this study, parametric studies are performed to investigate the variation of moment and shear force according to column-to-wall stiffness ratios and aspect ratios. Scaled factors applicable to the design of basement wall are proposed with the illustration of desist examples.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.415-420
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• 2003

This Study is performed to analyze the behavior of inverted T-shaped Composite Basement Wall(CBW). For this, it is purposed to analyze the failure mechanisms of inverted T-shaped composite basement wall and propose the method of evaluating strength for design. The failure mechanisms would be devided into 4 type mechanisms from previous experimental results, that is hanger failure, punching shear failure, flexural failure and the buckling of H-pile. A strength evaluation procedure for CBW is induced by analyzing respective failure mechanism. Then, the strength for actual structure consisted of inverted T-shaped composite basement wall was evaluated and the expected failure mechanism was determined.

• Journal of the Korean Society of Safety
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• v.27 no.3
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• pp.104-110
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• 2012

It is a common practice to design basement walls acting as a one-way slab or plate with idealized boundary conditions, resulting in potentially inefficient design. The walls are often supported by buttress columns and side walls in the vertical direction, thereby acting as a two-way slab. In this study, structural behavior of single-story, three-span basement wall subjected to lateral soil pressure was investigated. Three dimensional finite element analyses were conducted to determine the force distribution on the wall. Based on the numerical studies, a regression analysis was carried out to determine the design values of moments in vertical and horizontal directions as well as shear forces on the wall and design charts are developed. The proposed design method with accompanying design charts would enable practicing engineers to estimate member forces on the wall for preliminary design purpose without resorting to finite element analysis. Numerical examples demonstrated the applicability of the proposed method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.1
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• pp.93-101
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• 2010

When doing underground excavation works for the purpose of constructing large underground structures for a building in the limited space in downtown area, the stability of the adjacent ground must be top priority, and to accomplish this, it is essential to review the retaining wall construction carefully. H-Pile, which has been mainly used as a stress-carrying material in temporary earth-retaining structures, is most likely to be abandoned after completion of the works for the basement exterior wall in relation to contiguous bored piles, so it will result in a waste of material. To improve this situation, Basement Composite Wall where H-Pile and basement wall are compounded, has been developed. This wall is being used most frequently in many local construction sites. In this study, five specimens are made in order to evaluate the shear resistance of the basement composite wall and tested. Test parameter is the composition ratio and wall thickness according to shear connectors. Test result shows that the shear strength is improved when the composite ratio is increased but the magnitude is not much. A formula, which considers the contribution of concrete, web of H-pile as well as flange' effect in calculation of shear strength of composite basement wall, is suggested and used to calculation of the strength of specimens. It is found that there is a good co-relation between test result and the calculated one by the formula.

• Journal of the Korea Institute of Building Construction
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• v.9 no.6
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• pp.189-195
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• 2009

Recently, the urban centralization phenomenon appears to be growing. As a result, many vigorous efforts for the use of underground space are being made. In particular, the basement depth of construction in the downtown area has deepened and construction is often done close to adjacent buildings. In this case, generally, the underground construction approach mainly used is the composite basement wall system. However, a cost analysis of the basement composite wall system does not exist. Therefore, in this study, the cost of the composite basement wall system was analyzed. The percentage breakdown of costs were: buttress work processes, 3% form work processes, 26% reinforcement work processes, 12% support work processes, 42% and other processes,17%. Accordingly, it will be necessary when developing new technology and construction methods to determine the development focus.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.3
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• pp.176-184
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• 2007

The objective of this paper is to suggest a nonlinear analysis process to predict the structural behavior and strength of composite basement wall member combined with H-Pile. Therefore, the structural behavior of composite basement wall is studied and the special nonlinear characteristics of each elements such as H-Pile, concrete wall, and shear connectors are idealized using ATENA program. Finally, the result is compared with previous test result. Research result shows that there is a good co-relation between analysis and test results even if analysis result has little bit higher initial stiffness than test result. It can be concluded that the nonlinear behavior of composite basement wall is suitably predicted by using the contact element model in ATENA program as shear connector element.