• Geotechnical Engineering
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• v.8 no.1
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• pp.41-58
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• 1992

In the present study, an analytical solution method is proposed for the seismic design of anchored sheet pile walls used in port. The proposed analytical method deals with the anchored sheet pile walls with free earth support in sands and c- U soils, including the effects of hydrodynamic pressures and a condition of steady seepage between the two water levels. Also, the effects of various parameters(differential in water levels, anchor position, wall friction angle, dredge line slope, cohesion, adhesion etc.) on embedment depth, anchor force, and maximum bending moment are analyzed using the proposed method. In addition, comparisons between different definitions of safety factor are made, and necessary considerations required in the design of anchored sheet pile walls are examined.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.102-108
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• 2016

This paper presents a new strength method of underground box structures under additional surface load. An L-bracing using pre-flexed steel member threads called the "Pre-flex strength method" is used to improve capacity of the RC box structure under earth pressure due to additional surface load. The pre-flexed steel member is fixed the top and bottom of the structure after chemical anchor was installed by drilling hole on the box structure. The structural performance was evaluated analytically. 3 types of underground RC box structure were used; $2.0m{\times}2.0m$, $3.0m{\times}3.0m$ and $4.0m{\times}4.0m$. For the performance evaluation, structure analysis were performed on moment and shear resisting structures with and without pre-flex strength method. Numerical results confirmed that the proposed strength member system installed on underground RC box structures enhanced the strength capacity. The feasible region of the proposed pre-flex strength method in accordance with the earth pressure due to additional surface depth was evaluated.

• Journal of the Korean Geosynthetics Society
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• v.12 no.3
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• pp.43-53
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• 2013

In this study, an analysis about the causes of different types of excavation on accidents is required in order to prevent the frequently occurring accidents related to the earth retaining structure and excavation. Also, analysis of influence was performed by using numerical typical soil conditions and construction trend using numerical analysis method. According to the analysis results of 25 accident cases, the main influence factors were found as following: insufficient of soil survey, instability of temporary facility and lack of groundwater treatment, etc. Furthermore, in the numerical analysis result of 22 cases, drainage method was occurred larger settlement than waterproof method in the Inland. In case of applying the earth anchor method, it needs more detailed in the regions, which are discovered soft ground or rock discontinuities. Also, The consolidated clay absolutely needs further consideration of excess hydrostatic pressure.

• Geomechanics and Engineering
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• v.15 no.5
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• pp.1061-1070
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• 2018

The main purpose of retaining wall methods for deep excavation is to keep the construction site safe from the earth pressure acting on the backfill during the construction period. Currently used retaining wall methods include the common strut method, anchor method, slurry wall method, and raker method. However, these methods have drawbacks such as reduced workspace and intrusion into private property, and thus, efforts are being made to improve them. The most advanced retaining wall method is the prestressed wale system, so far, in which a load corresponding to the earth pressure is applied to the wale by using the tension of a prestressed (PS) strand wire. This system affords advantages such as providing sufficient workspace by lengthening the strut interval and minimizing intrusion into private properties adjacent to the site. However, this system cannot control the tension of the PS strand wire, and thus, it cannot actively cope with changes in the earth pressure due to excavation. This study conducts a preliminary numerical analysis of the field applicability of the controllable prestressed wale system (CPWS) which can adjust the tension of the PS strand wire. For the analysis, back analysis was conducted through two-dimensional (2D) and three-dimensional (3D) numerical analyses based on the field measurement data of the typical strut method, and then, the field applicability of CPWS was examined by comparing the lateral deflection of the wall and adjacent ground surface settlements under the same conditions. In addition, the displacement and settlement of the wall were predicted through numerical analysis while the prestress force of CPWS was varied, and the structural stability was analysed through load tests on model specimens.

• Journal of Korean Association for Spatial Structures
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• v.11 no.2
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• pp.129-138
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• 2011

Construction methods for underground structure are classified as bottom-up, up-up, and top-down methods depending on the procedure of construction related to a superstructure. In top-down construction methods, building's main structure is built from the ground level downwards by sequentially alternating ground excavation and structure construction. In the mean time, the main structure is also used as supporting structure for earth-retaining wall, which results in the increased stability of the earth-retaining wall due to the minimized deformation in adjacent structures and surrounding grounds. In addition, the method makes it easy to secure a field for construction work in the downtown area by using each floor slabs as working spaces. However top-down construction method is often avoided since an excavation under the slab has low efficiency and difficult environment for work, and high cost compared with earth anchor method. This paper proposes a combined construction method where semi-open cut is selected as excavation work, slurry as earth -retaining wall and CWS as top-down construction method. In the case study targeted for an actual construction project, the proposed method is compared with existing top-down construction method in terms of economic feasibility, construction period and work efficiency. The proposed construction method results in increased work efficiency in the transportation of earth and sand, and steel frame erection, better quality management in PHD construction, and reduced construction period.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.4
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• pp.171-187
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• 1991

In the present study, an analytical solution method is proposed for the seismic design of cantilever sheet pile walls and anchored sheet pile walls used in harbor construction. Seepage pressures, together with a change in magnitudes of effective horizontal soil pressures, are included in the proposed solution method. Also, the Mononobe-Okabe analysis as well as the Westergaard and Matsuo-Ohara theory of hydrodynamic pressures is used in the proposed method. Further, the choice of values for safety factors is examined for the seismic design of anchored sheet pile walls, and the effects of various parameters(dredge line slope, differential in water levels, anchor position, and wall friction angle) on embedment depth, anchor force, and maximum bending moment are analyzed for anchored walls in dense sand deposits. In addition. the tables that could be used for preliminary seismic design of anchored walls in dense sands are presented. The proposed method deals with the sheet pile walls with free earth support.

• Journal of the Society of Disaster Information
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• v.12 no.4
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• pp.366-372
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• 2016

Recently in case of the concrete retaining wall precast technological change in the field assembled by the way. A precast wall is devied into upper and lower respectively, and the way, assembled in field is being performed. But the assembled part could have been damaged by the earth pressure in a relatively high buttress wall. And, it have been pointed out that large-scale disaster can be occurred. Thus, in this thesis, a structural stability for the buttressed retaining wall with pre-cast joint method was analyzed by a numerical analysis method. The structural stability of the three height retaining wall(7.6m, 8.5m, 10m) was conducted respectively for earth pressure. The maximum principal stress applied to the concrete retaining wall was analyzed to occur locally in the vicinity of the fixing anchor as 23.3 ~ 43.2 MPa.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.345-349
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• 2019

In Korea, the mountainous area occupies more than 70% of the whole country, cutting of earth slope that cuts a part of the ground surface is widely used when building infrastructures such as road, railroad, and industrial complex construction. In recent years, regulations on environmental damage have become more strict, and various methods have been developed and applied. Among them, Concrete-Panel Retaining Wall technique is actively applied. Concrete-Panel Retaining Wall is a method to resist horizontal earth pressure by forming a wall by attaching a precast retaining wall to the front of the support material and increasing the shear strength of the disk through reinforcement of the support material. Soil nailing, earth bolt, and ground anchor are used as support material. Among them, ground anchor is a more aggressive reinforcement type that introduces tensile load in advance to the steel wire, and a large concentrated load acts on the front panel. This concentrated load is a factor that creates cracks in the concrete panel and reduces the durability of the retaining wall itself. In this study, steel pipe sleeves and reinforcements were purchased at the anchorage of the panel to prevent cracks, and by applying bumpy shear keys to the end of the panel, the weakness of the individual behavior of the existing grout anchors was improved. The problem of degraded landscape by exposure to front concrete of retaining wall and protrusion of anchorage was solved by the production of natural stone patterns and the construction of sections that do not protrude the anchorage. In order to verify the effectiveness of anti-crack sleeves and reinforcements used in the null, indoor testing and three-dimensional numerical analysis have been performed, and the use of steel pipe sleeves and reinforcements has demonstrated the overall strength increase and crack suppression effect of panels.

• Journal of the Korean Geotechnical Society
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• v.16 no.1
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• pp.19-30
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• 2000

The major design parameters of the anchored sheet-pile wall include the determination of required penetration depth, the force acting on the anchor, and the maximum bending moment in the piling. Blum solved the fixed earth supported wall using the equivalent beam method, assuming that the wall can be separated into upper and lower parts of the point of contraflexure. Design charts help designer by simplifying the design procedure. But they have some difficulties under some Geotechnical and geometrical conditions. For example, the conventional design charts can compute design parameters only when the ground water table exists above the dredge line. In this paper, the design charts which can be used for the ground water table existing under the dredge line are presented. And simplified formulae are developed by regression analysis. It is found that simplified formulae are not only very useful for the practice of design but also they can evaluate the result of numerical methods or design charts.

• Journal of the Korean Geotechnical Society
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• v.20 no.9
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• pp.57-64
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• 2004

In order to establish the design method of anchored retention walls in cut slope, the behavior of anchored retention walls and backside ground needs to be investigated and checked in detail. In this study, the behavior of anchored retention walls was investigated by instrumentation installed in cut slope for an apartment construction site stabilized by a row of piles and anchored retention walls. When the anchor was installed at each excavating stages, the horizontal deflection of retention wall decreased, while the horizontal deformation of backside ground increased. The deflection of anchored retention wall decreased as the anchor was prestressed. The prestressed anchor farce has a great effect on the deflection of retention walls, while it has little effect on the deformation of its backside ground. The maximum horizontal deflection of anchored retention walls was developed between $1\%\;and\;4\%$ of excavation depth, which are $2\~8$ times larger than max. horizontal deflection of anchored retention walls including rock layers with backside horizontal ground. Meanwhile, SLOPILE (ver. 3.0) program analyzes the slope stability effects for anchored retention walls. As a result of analysis on slope stability analysis, the lateral earth pressure applied at anchored retention piles could be used as the mean values of empirical lateral pressures using anchored retention wall with horizontal ground at its backside.