• Title/Summary/Keyword: retaining structures

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Investigation on seismic behavior of combined retaining structure with different rock shapes

  • Lin, Yu-liang;Zhao, Lian-heng;Yang, T.Y.;Yang, Guo-lin;Chen, Xiao-bin
    • Structural Engineering and Mechanics
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    • v.73 no.5
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    • pp.599-612
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    • 2020
  • A combination of a gravity wall and an anchor beam is widely used to support the high soil deposit on rock mass. In this study, two groups of shaking table test were performed to investigate the responses of such combined retaining structure, where the rock masses were shaped with a flat surface and a curved surface, respectively. Meanwhile, the dynamic numerical analysis was carried out for a comparison or an extensive study. The results were studied and compared between the combined retaining structures with different shaped rock masses with regard to the acceleration response, the earth pressure response, and the axial anchor force. The acceleration response is not significantly influenced by the surface shape of rock mass. The earth pressure response on the combined retaining structure with a flat rock surface is more intensive than the one with a curved rock surface. The anchor force is significantly enlarged by seismic excitation with a main earthquake-induced increment at the first intensive pulse of Wenchuan motion. The value of anchor force in the combined retaining structure with a flat rock surface is generally larger than the one with a curved rock surface. Generally, the combined retaining structure with a curved rock surface presents a better seismic performance.

Seismic Design of Soil-Reinforced Segmental Retaining Walls (블록식 보강토 옹벽의 내진설계)

  • 유충식
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.11c
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    • pp.69-83
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    • 1999
  • Soil-reinforced segmental retaining walls(SRW) have been proven to be high earthquake-resistant structure during recent earthquakes in United States and Japan. The mechanicals behavior of the SRWs under seismic loading, however, has not been fully understood. Although the seismic design issues for the civil engineering structures have gained much attention in Korea due to the increase in frequency of earthquake occurrence, the seismic design for the SRWs has not been being implemented. This study has been undertaken with the aim of developing a more rational seismic design/analysis method for soil-reinforced segmental retaining walls. This paper present fundamentals of current seismic design/analysis method and the results of a comparative study between NCMA and FHWA design guidelines, Practical implications of the findings from this study are discussed in great detail.

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A study on horizontal stress of retaining walls caused by train loading (열차하중 작용 시 연직토류벽에 발생하는 수평응력 고찰)

  • Kim, Dae-Sang;Kim, Hyung-Geun;Kim, Ki-Hwan
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.964-972
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    • 2008
  • In the retaining wall design process, track and train loads are usually considered as uniform surcharge loads and strip loads. In this paper, the lateral(horizontal) earth pressure on retaining structures caused by track and train load are calculated using the Boussinesq solution. And also total horizontal force per unit length and the location of the resultant force were estimated with the changes of loading locations and widths of the loadings. The maximum horizontal earth pressure and the location of it for high-speed train load were 11.83kPa and 1.7m at the loading condition 2m away from retaining walls.

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Correlation between Strut Preloading and Earth Retaining Structures in Braced Excavations (버팀굴착시 버팀대 선행하중과 흙막이 구조물과의 상호 관계)

  • 오성남;조현태;박기태;양구승
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.129-136
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    • 1999
  • The use of strut preloading method is gradually increasing in braced excavations in Korea. And it is necessary to analyse the effects of strut preloading on the wall deflection, bending moment and strut axial force etc. In this study, by using the analysis method of beams on elasto-plastic foundations, parametric studies of correlation between preloading and earth retaining structures in sandy soils were peformed in strut preloading application. As results, about 50% of design strut load was effective as a preloading force in considering the displacement and member forces of structures. And at least the effective stiffness of strut should be over 25% of the ideal value in order to restrain the excessive increase of wall deflection and bending moments. In order to protect excessive movements in braced excavation, to preload the strut was rather effective way than to increase the stiffness of strut and braced wall, but the excessive axial force of strut should be checked simultaneously.

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Analysis on the Characteristics of the Landslide in Maeri (IV) - With a Special Reference on Stability Analysis of Structures - (매리 땅밀림형 산사태(山沙汰)의 발생특성(發生特性)에 관한 분석(分析) (IV) - 구조물(構造物)의 안정해석(安定解析)을 중심(中心)으로 -)

  • Park, Jae-Hyeon;Bae, Jong Soon;Choi, Kyung;Ma, Ho-Seop;Lee, Jong-Hak;Youn, Ho-Jung
    • Journal of Korean Society of Forest Science
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    • v.95 no.1
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    • pp.5-11
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    • 2006
  • This study was carried out to analyse the landslide characteristics by structure stability analysis at the landsliding area occurred in Maeri, Sangdong-myeon, Gimhaesi, Gyeongsangnam-do. External stability of the retaining wall and the retaining stonewall was accessed as unstable condition except for the II-D profile. It is needed to consider a counter plan to stabilize the structure. Also, it is necessary to stabilize the unstable retaining wall reinforced with adding draining measure. It is useful to reduce the load from upper retaining stonewall by alleviating the slope degree from stonewall structures.

A Study of Connection Stability for Reinforced Retaining Wall Constructed with Soilbag with Varying Connection Strength (연결강도 변화에 의한 Soilbag 보강토 옹벽 연결부의 안정성 평가)

  • Lee, Sang-Moon;Choi, Changho;Shin, Eun-Chul
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.1
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    • pp.101-107
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    • 2013
  • Environmental-friendly and economical construction are the recent issues for civil structures and soilbag as facing wall is widely used for cut-slope remediation projects. However, the stability of structures is an important issue for the use of environmental-friendly and economical materials. In order to understand the stability of soilbag reinforced retaining wall, tensile resistance, rupture, tensile strength, and internal/external safety factor of the wall were analyzed with MSEW program and the results were compared to the safety factor of block-type reinforced walls. The stability of retaining wall was analyzed with reduction coefficients of connection strength to check the connection stability. Because it is possible to move between soilbag and geogrid connector for soilbag retaining wall, the safety factor of the wall was analyzed with different inclination angles of soilbag. The analysis result shows that the connection strength and internal/external stability of soilbag reinforced wall satisfy the stability criteria.

Effect of hanging-type sand fence on characteristics of wind-sand flow fields

  • Cheng, Jian-jun;Lei, Jia-qiang;Li, Sheng-yu;Wang, Hai-feng
    • Wind and Structures
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    • v.22 no.5
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    • pp.555-571
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    • 2016
  • A hanging-type sand-retaining wall is a very common sand-blocking fence structure used to prevent sand movement. This type of wall is widely used along the Qinghai-Tibet and Gobi desert railways in Xinjiang, Western China. To analyze the characteristics of wind-sand flow fields under the effect of such a sand fence structure, a wind tunnel test and a field test were carried out. The wind tunnel test showed the zoning characteristics of the flow fields under the effect of the hanging-type sand-retaining wall, and the field test provided the sediment transport data for effective wind-proof interval and the sand resistance data in the front and behind the sand-retaining wall. The consistency of the wind-sand flow fields with the spatial distribution characteristic of wind-carried sand motion was verified by the correspondences of the acceleration zone in the flow field and the negative elevation points of the percentage variations of the sand collection rate. The spatial distribution characteristic of the field sand collection data further showed the spatial structural characteristic of the sandy air currents under the action of the hanging-type sand-retaining wall and the sand resistance characteristic of the sand-retaining wall. This systematic study on the wind-sand flow fields under the control of the hanging-type sand-retaining wall provides a theoretical basis for the rational layout of sand control engineering systems and the efficient utilization of a hanging-type sand-retaining wall.

The Evaluation Applying Limit State Method for the Concrete Retaining Wall Structures (콘크리트 옹벽구조물의 한계상태설계법 적용성 평가)

  • Yang, Taeseon;Jeong, Jongki;Seo, Junhee;Baek, Seungcheol
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.7
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    • pp.59-66
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    • 2014
  • Nowadays, some studies are performed in order to introduce the Limit State Design method widely used in foreign work sites. LRFD (Load Resistance Factor Design) method is widely used in the fields in which the data accumulation is possible - such as deep foundations, and shallow foundations, etc. The limit state design in the retaining walls is insufficient in the country owing to difficulties applying load tests. The limit state design method for retaining wall structures are studied based upon the National Retaining wall Design Standard legislated in 2008 by Ministry of Land, Transport, and Maritime Affairs. In this paper several retaining walls were calculated according to LRFD design criteria analysis using the general program with limit state design method and the factor of safety for sliding and overturning. Comparing with their results, the Taylor's series simple reliability analysis was performed. In the analysis results of retaining wall section, safety factors calculated by LRFD were found to be lowered than those calculated in current WSD, and it is possibly judged to be economic design by changing wall dimensions. In the future, pre-assessment of the geotechnical data for ensuring the reliability and the studies including reinforced retaining walls with ground anchor are needed.

Coefficient charts for active earth pressures under combined loadings

  • Zheng, De-Feng;Nian, Ting-Kai;Liu, Bo;Yin, Ping;Song, Lei
    • Geomechanics and Engineering
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    • v.8 no.3
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    • pp.461-476
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    • 2015
  • Rankine's theory of earth pressure cannot be directly employed to c-${\phi}$ soils backfill with a sloping ground subjected to complex loadings. In this paper, an analytical solution for active earth pressures on retaining structures of cohesive backfill with an inclined surface subjected to surcharge, pore water pressure and seismic loadings, are derived on the basis of the lower-bound theorem of limit analysis combined with Rankine's earth pressure theory and the Mohr-Coulomb yield criterion. The generalized active earth pressure coefficients (dimensionless total active thrusts) are presented for use in comprehensive design charts which eliminate the need for tedious and cumbersome graphical diagram process. Charts are developed for rigid earth retaining structures under complex environmental loadings such as the surcharge, pore water pressure and seismic inertia force. An example is presented to illustrate the practical application for the proposed coefficient charts.