• Geomechanics and Engineering
• /
• v.12 no.4
• /
• pp.675-688
• /
• 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.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.1020-1025
• /
• 2004

This research reviews the characteristics of earth pressure incurred by GRS-RW mainly used in the railroad design in order to resist large lateral load caused by train and additional load induced by facilities such as noise barrier fences, electric poles, etc. The results of test shows the existence of arching effect that horizontal earth pressure increases in the backfill while earth pressure applying to the wall reduced under GRS-RW system. In both cases, unreinforced wall and GRS-RW system, the coefficient of earth pressure (K) is about 0.4 at the rest. However, after lateral displacement occurs, the earth pressure nearly reduce down to zero under GRS-RW system while the earth pressure decreases up to 0.12 in case of unreinforced retaining wall.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.10a
• /
• pp.1144-1156
• /
• 2008

In this paper, heaving phenomenon is analyzed by laboratory tests. A laboratory test is consist of building soft clay foundation in plane-strain soil tank, construction of retaining wall, and excavation work. And range of shear strain, and destruction shape about soft clay foundation is compared, and analyzed with results of proposal formula. Using this study, safety factor is suggested for heaving phenomenon in the construction of wall on the soft clay. Actual theory is suggested by this suggested safety factor. There are various proposal formula for heaving phenomenon. For example, Terzaghi & Peck, Tschebotarioff, Bjerrum & Eide(Experience formula) and so on. Terzaghi & Peck's proposal formula is chosen, compared with laboratory test's result and analyzed in this study. A soft clay used in study is assumed homogeneous. A Depth of foundation is enough to observe shear strain by heaving phenomenon. Retaining wall is enough hard not to have vertical displacement.

• Journal of the Korean Institute of Rural Architecture
• /
• v.16 no.4
• /
• pp.59-66
• /
• 2014

This paper deals with vibration of plates with concentrated mass on elastic foundation. The object of investigating natural frequencies of tapered thick plate on pasternak foundation by means of finite element method and providing kinetic design data for mat of building structures. Free vibration analysis that tapered thick plate in this paper. Finite element analysis of rectangular plate is done by use of rectangular finite element with 8-nodes. In order to analysis plate which is supported on pasternak foundation. The Winkler parameter is varied with 10, $10^2$, $10^3$ and the shear foundation parameter is 5, 10. This paper is analyzed varying thickness by taper ratio. The taper ratio is applied as 0.0, 0.25, 0.5, 0.75, 1.0. And the Concentrated Mass is applied as P1, Pc, P2 respectively.

• Journal of the Korean Geotechnical Society
• /
• v.21 no.4
• /
• pp.135-143
• /
• 2005

This paper presents a case history of a geosynthetics-reinforced segmental retaining wall, which collapsed during a severe rainfall immediately after the completion of the wall construction. In an attempt to identify possible causes for the collapse, a comprehensive investigation was carried out including physical and strength tests on the backfill, stability analyses on the as-built design based on the current design approaches, and slope stability analyses with pore pressure consideration. The investigation revealed that the inappropriate as-built design and the bad-quality backfill were mainly responsible for the collapse. This paper describes the site condition including wall design, details of the results of investigation and finally, lessons learned. Practical significance of the findings from this study is also discussed.

• Journal of the Korean Geotechnical Society
• /
• v.18 no.4
• /
• pp.7-19
• /
• 2002

This paper presents the results of an investigation on the effect of foundation stiffness on the performance of soil-reinforced segmental retaining walls (SRWalls). Laboratory model tests were performed using a reduced-scale physical model to capture the fundamentals of the manner in which the foundation stiffness affects the behavior of SRWalls. A series of finite-element analyses were additionally performed on a prototype wall in order to supplement the findings from the model tests and to examine full-scale behavior of SRWalls encountered in the field. The results of the present investigation indicate that lateral wall displacements significantly increase with the decrease of the foundation stiffness. Also revealed is that the increase in wall displacements is likely to be caused by the rigid body movement of the reinforced soil mass with negligible internal deformation within the reinforced soil mass. The findings from this study support the current design approaches, in which the problem concerning the foundation condition are treated in the frame work of the external stability rather than the internal stability. The implications of the findings from this study to current design approaches are discussed in detail.

• Geomechanics and Engineering
• /
• v.15 no.6
• /
• pp.1173-1182
• /
• 2018

The coal wall, gob-side backfill, and gangues in goaf, constitute the support system for Gob-side entry retaining (GER) in coal mines. Reasonably allocating and utilizing their bearing capacities are key scientific and technical issues for the safety and economic benefits of the GER technology. At first, a mechanical model of GER was established and a governing equation for coordinated bearing of the coal-backfill-gangue support system was derived to reveal the coordinated bearing mechanism. Then, considering the bearing characteristics of the coal wall, gob-side backfill and gangues in goaf, their quantitative design methods were proposed, respectively. Next, taking the No. 2201 haulage roadway serving the No. 7 coal seam in Jiangjiawan Mine, China, as an example, the design calculations showed that the strains of both the coal wall and gob-side backfill were larger than their allowable strains and the rotational angle of the lateral main roof was larger than its allowable rotational angle. Finally, flexible-rigid composite supporting technology and roof cutting technology were designed and used. In situ investigations showed that the deformation and failure of surrounding rocks were well controlled and both the coal wall and gob-side backfill remained stable. Taking the coal wall, gob-side backfill and gangues in goaf as a whole system, this research takes full consideration of their bearing properties and provides a quantitative basis for design of the support system.

• Journal of the Korean Geotechnical Society
• /
• v.18 no.3
• /
• pp.61-72
• /
• 2002

This paper presents the results of investigation on the behavior of soil-reinforced segmental retaining walls in tiered arrangement using the finite element method of analysis. 2D finite element analyses were performed on tiered walls with two levels of offset distance. Cases with equivalent surcharge as suggested by the NCMA design guideline were additionally analyzed in an attempt to confirm the appropriateness of the equivalent surcharge model adopted by NCMA. Deformation characteristics of a tiered wall with small offset distance suggest a compound mode of failure and support current design approaches requiring a global slope stability analysis for design. Also revealed is that the interaction between the upper and lower walls significantly affects not only the performance of the lower wall but also the upper wall, suggesting that the upper walls should also be designed with due consideration of the interaction.

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.2
• /
• pp.61-68
• /
• 2010

Recently, it is a trend of the underground excavation to become larger and deeper for more effective use of available space and with the advent of new excavation technologies. The ground typically has a complex stratigraphy. The excavation can lead to large deformation in the nearby structures and large earth pressure on the wall. This can lead to serious problem in the stability of the wall. For the retaining wall to be safely constructed, it is important that the stratigraphy and engineering properties of the ground be accurately estimated, based on the excavation plan and appropriate excavation method. This study uses the measured field data and numerical results to characterize the characteristics of the lateral deformation of the retaining wall. A touredof six field data were analysed. SUNEX, a numerical program which uses the elasto-plastic model to represent the soil, was used. It was shown that the measured deformations exceeded the proposed values for shallow excavations. Overall, the maximum lateral deformation was within the proposed value and hence, the walls were analyzed as safe.

• Journal of the Korean Geosynthetics Society
• /
• v.16 no.2
• /
• pp.165-174
• /
• 2017

There are natural disasters caused by abnormal climate in the world. In particular, there are frequent disasters such as floods and landslides caused by rainfall in summer. Rainfall will have a major impact on the stability of a retaining wall. If drainage during rainfall activities within the retaining wall is not made properly, permeated water brings a significant increase in pore pressure inside of the backfill soil and reduces the shear strength of the soil. Therefore, research how to install the drainage layers to reduce the infiltrated water inside of the backfill soil is very necessary. In this study, we performed a numerical modeling to find the optimum installation conditions of the location and number of drainage layer related to stability of the reinforced retaining wall during rainfall installed geosynthetics.