• Earthquakes and Structures
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• 제24권3호
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• pp.205-215
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• 2023

Currently, many studies are underway at home and abroad on the seismic performance evaluation and dry construction method of the masonry structure. In this study, a dry stack masonry wall system without mortar using concrete blocks is proposed, and investigate the seismic performance of dry filling wall frames through experimental studies. First, two types of standard blocks and key blocks were designed to assemble dry walls of concrete blocks. And then, three types of experiments were manufactured, including pure frame, 1/2 height filling wall frame, and full height filling wall frame, and cyclic load experiments in horizontal direction were performed to analyze crack patterns, load displacement history, rebar deformation yield, effective stiffness change, displacement ductility, and energy dissipation capacity. According to the experimental results, the full height filling wall frame had the largest horizontal resistance against the earthquake load and showed a high energy dissipation capacity. However, the 1/2 height filling wall frame requires attention because the filling wall constrains the effective span of the column, limiting the horizontal displacement of the frame. In addition, the concrete block was firmly assembled in the vertical direction of the wall as the horizontal movement between the concrete blocks was allowed within installation margin, and there was no dropping of the assembled concrete block.

• 한국지반신소재학회논문집
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• 제4권4호
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• pp.47-56
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• 2005

산업의 발달에 따라 효율적인 부지의 활용이 요구되면서 옹벽의 사용이 많아지게 되었다. 이러한 옹벽 중 지오그리드를 보강재로 하고 콘크리트 블록을 전면판으로 사용하는 블록식 보강토 옹벽(dry cast modular block wall, MBW)은 그 시공의 편이성과 경제성으로 인해 1980년대 초부터 꾸준히 사용이 증가하고 있는 추세이다. 그러나 이 방법은 토압이론에 기초하는 특성상 양질의 사질토를 사용하여야 한다. 이에 비하여 보강사면(reinforced soil slopes, RSS)은 $70^{\circ}$ 이하의 경사를 갖는 보강토체로서 공사에 사용되는 흙이 블록식 보강토 옹벽보다는 훨씬 광범위하다. 또한 본 공법은 양질의 사질토 구득이 어려운 점을 보완하고, 개발되는 부지의 효용성을 극대화하기 위하여 부지의 경계면에서 일정 높이의 수직으로 축조되는 블록식 보강토 옹벽을 축조하고 그 위에 보강사면을 축조하였다. 본 연구는 이러한 두 공법의 장점을 활용한 복합식 보강토체를 설계하고 시공한 결과에 대하여 설계 및 시공 시 고려하여야 할 사항에 대하여 연구하였다.

• Geomechanics and Engineering
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• 제12권4호
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• pp.675-688
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• 2017

The anchor block is a specially designed concrete member intended to withstand pullout or thrust forces from backfill material of an internally stabilized anchored earth retaining wall by passive resistance of soil in front of the block. This study presents small-scale laboratory experimental works to investigate the pullout capacity of a concrete anchor block embedded in air dry sand and located at different distances from yielding boundary wall. The experimental setup consists of a large tank made of fiberglass sheets and steel framing system. A series of tests was carried out in the tank to investigate the load-displacement behavior of anchor block. Experimental results are then compared with the theoretical approaches suggested by different researchers and codes. The appropriate placement of an anchor block and the passive resistance coefficient, which is multiplied by the passive resistance in front of the anchor block to obtain the pullout capacity of the anchor, were also studied.

• 한국농촌건축학회논문집
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• 제2권2호
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• pp.115-126
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• 2000

Retaining walls are used to prevent excessive movement of retained soils. Typical retaining walls include gravity, reinforced concrete, reinforced earth and tie-back. However, from a practical viewpoint there are still drawbacks among these often constructed retaining walls. New types of retaining walls constructed with precast concrete blocks are proposed. This type of retaining wall is incorporates each blocks interconnected with adjacent block by connecting unit to build up a flexible retaining-wall system. This paper focus to behavior characteristics includes deformation and distribution of lateral earth pressure by loading tests and FEM analysis. For model tests, a 1/10 scale reduce models are manufactured include unevenness part, drainage hole and connecting unit and steel wire used to connect each blocks with adjacent block. To simulate the real retaining walls closely, uneven parts are interconnected each other and the construction type of blocks and wall front inclination are varied to investigate the relative displacement of individual block and the location of maximum deformation of wall as increasing surcharging. Additionally, PENTAGON3D, which solve the geotechnical and other problem, used for verifying and comparing with model tests.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 가을 학술발표회 논문집
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• pp.315-321
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• 2001

Since 1984, block-type reinforced earth wall with geogrid reinforcement has been widely used for retaining wall applications till now in Korea. The use of geogrid as a reinforcement in the reinforced earth wall is steadily increased in an amount over 1,500,000㎡ in a year However, still need exists that some problems in design and construction practices should be made to review, Therefore, this paper reviewed reasonable criteria for selection of backfills, design details considering the effect of the upper soil slope on reinforced earth wall, horizontal displacement of facing block during compaction, and the damage of geogrid reinforcements on the edge part of facing block. Finally, alternative methods of measures on those problems are proposed.

• 터널과지하공간
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• 제1권
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• pp.66-74
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• 1991

The block theory with stereographic projection was applied and analyzed on the tunnel section of Samcheok Coal Mine. The results were as follows ; 1) Prevail orientations of discontinuity of sandstone around the main driftway of Samcheok Coal Mine were $(327^{\circ},\;44^{\circ}),\;(13^{\circ},\;24^{\circ}),\;(204^{\circ},\;65^{\circ})$ and $(225^{\circ},\;77^{\circ})$ in dip and dip direction, respectively. 2) Movable blocks of the site were 0110, 0111, 1110(roof), 0100, 0110, 1110(right wall) and 0001, 1001, 1011(left wall). Because of the direction of tunnel, blocks of the left wall was safe. thus key blocks were those of the roof and the right wall. Maximum height of key block was larger than the width of the tunnel but 2m of the yielded zone is expected in general for 5m width tunnel. 3) It is shown that block theory is applicable to large cavern in hard rock analysis.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 가을 학술발표회 논문집
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• pp.465-472
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• 1999

A small scale model reinforced soil wall was constructed in a laboratory to investigate role of the wall facing and the effect of construction sequence on the wall. A panel type facing system and a block facing system are introduced for test. These two different types of facing adapt different construction procedure. The model wall is built with geogrid reinforcement, sand, and the facings on rigid surface. The model wall is instrumented with earth pressure gauges, LVDTs, and strain gauges. It is found in this study that the reinforced soil wall system built with geogrids and panel type facing system be the safest reinforced soil wall ever compared to the block type facing. Thus, it is recommended that study for the wall system be necessary for further wide usage in the future.

• 한국안전학회지
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• 제24권5호
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• pp.57-62
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• 2009

In this study, the numerical analyses regarding the distance between the guardrail and the reinforced earth wall as parameter were performed to determine the safe distance of guardrail installed on reinforced earth wall from the reinforced earth wall. The analyses were fulfilled by increasing the distance between the guardrail and reinforced earth wall from 150mm to 750mm. The computer program used in this research is LS-DYNA, which is very' popular in analysis of vehicle collision. Ford single unit truck in NCAC was employed as the model of vehicle and the velocity of vehicle collision was 80km/hr. As a results of analyses, the safety of guardrail was secured regardless of the distance between the guardrail and block of reinforced earth wall. However, to secure the safety of block of reinforced earth wall the distance between the guardrail and block of reinforced earth wall should be over 600mm.

• Computers and Concrete
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• 제10권1호
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• pp.1-18
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• 2012

This paper presents the details of studies conducted on hollow concrete block masonry (HCBM) units and wall panels. This study includes, compressive strength of unit block, ungrouted and grouted HCB prisms, flexural strength evaluation, testing of HCBM panels with and without opening. Non-linear finite element (FE) analysis of HCBM panels with and without opening has been carried out by simulating the actual test conditions. Constant vertical load is applied on the top of the wall panel and then lateral load is applied in incremental manner. The in-plane deformation is recorded under each incremental lateral load. Displacement ductility factors and response reduction factors have been evaluated based on experimental results. From the study, it is observed that fully grouted and partially reinforced HCBM panel without opening performed well compared to other types of wall panels in lateral load resistance and displacement ductility. In all the wall panels, shear cracks originated at loading point and moved towards the compression toe of the wall. The force reduction factor of a wall panel with opening is much less when compared with fully reinforced wall panel with no opening. The displacement values obtained by non-linear FE analysis are found to be in good agreement with the corresponding experimental values. The influence of mortar joint has been included in the stress-strain behaviour as a monolith with HCBM and not considered separately. The derived response reduction factors will be useful for the design of reinforced HCBM wall panels subjected to lateral forces generated due to earthquakes.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 토목섬유기술위원회 학술세미나 논문집
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• pp.1-11
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• 2001

This Paper presents the result of a parametric study on the behavior of stiffened grid reinforced segmental wall resting on non-yielding foundation. The parametric study was conducted using the nonlinear finite element analysis. In the finite element analysis, the step by step construction of the wall such as backfill, block reinforcement, block/backfill and soil/reinforcement interfaces were carefully modeled. The mechanical behavior of stiffened grid reinforced segmental walls was then investigated based on the result of analysis with emphasis on the effect of reinforcement stiffness on the behavior of the wall. The results of analysis indicate that the horizontal wall displacement decrease; with increasing the reinforcement stiffness at a decreasing rate, and that the horizontal stress at the back of the reinforced soil block does not much vary with the reinforcement stiffness. It is also revealed that the calculated maximum vertical stress at the base of the reinforced soil block agrees well with that based on the Meyerhof distribution and that the reinforcement and the connection force are considerably smaller than what might be expected based on the current design assumptions. The implications of the findings from this study to current design approaches were discussed in detail.