Performance of Back-to-Back Geogrid Reinforced Soil Retaining Walls for Railways during Service

Author(s):  
Guangqing Yang ◽  
Yunfei Zhao ◽  
Zhijie Wang ◽  
He Wang

To investigate the performance of a reinforced soil retaining wall during service for a passenger-dedicated railway, long-term remote observation testing of the back-to-back geogrid reinforced retaining wall (BBGRSW) of Qing-Rong passenger-dedicated railway in Shandong Province was conducted for 60 months. The performance of the reinforced retaining wall was investigated after construction, and the lateral earth pressure of the reinforced soil wall was analyzed. The vertical stress on the wall and tension on the geogrid were measured using pressure cells and flexible deformation gauges, thereby resulting in the distribution of data and changes in the service period. The test results show that the pressure and deformation of the wall are almost stable. It was determined that the lateral earth pressure on the back of the wall panel was approximately 119.2% of the completion time during the 60 months after construction. The vertical stress on the reinforced soil retaining wall remained approximately stable 60 months post-construction. The maximum strain of the measured geogrids accounted for less than 30% of the peak strain. Moreover, the deformation of the wall was relatively small, which indicated that both sides of the wall remained in good condition. These research results can serve as a reference for the design optimization of reinforced soil retaining walls for high-speed railways.

2013 ◽  
Vol 353-356 ◽  
pp. 368-373 ◽  
Author(s):  
Hong Bo Zhang ◽  
Jian Qing Wu ◽  
Ying Yong Li ◽  
Xiu Guang Song ◽  
Zhi Chao Xue

The recent research and development of the reinforced retaining wall is composed of cantilevered reinforced concrete retaining walls which symmetric set on both sides of subgrade and through roadbed width of counter-pulled anchors. The prestressing force can be applied on anchors.The retaining wall has the advantange of high safety, lateral small deformation , wide applicable range and low requirements for the foundation bearing capacity. But due to the lateral restraint of bolt, the soil pressure distributions of retaining wall change a lot. The change will have a significant impact on structures. In order to reveal the reinforced soil retaining wall pressure distributions, laboratory model test was done. The monitoring instruments such as earth pressure cells, anchor rope dynamometers and dial indicators were installed. Research and analysis on the loading process reinforced type soil retaining wall under soil pressure, the lateral earth pressure and anchor rope tension change rule were researched and analysed. The experimental results showed that with the increasing of filling soil height, the retaining wall had a tendency to tilt outward. The basolateral external pressure is larger than the inside pressure. At the same time, anchor tension increased as the top loading increased. Lateral earth pressure distribution is parabolic. Soil pressure around the anchor is larger than other area, the soil arch effect is significant.


2019 ◽  
Vol 281 ◽  
pp. 02008
Author(s):  
Hicham Alhajj Chehade ◽  
Daniel Dias ◽  
Marwan Sadek ◽  
Fadi Hage Chehade ◽  
Orianne Jenck

Assessment of internal seismic stability of geosynthetic reinforced cohesive soil retaining walls with likelihood for developing cracks in the failure mechanism is typically done with the limit equilibrium method. However, in this paper, the kinematic theorem of limit analysis combined with the discretization method are used to implement the crack formation in the collapse mechanism in the internal seismic assessment of geosynthetic reinforced soil retaining walls within the framework of the pseudo-static approach. The presence of the crack leads to an increase of the required reinforcement strength that prevent the failure of the structure.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Suk -Min Kong ◽  
Dong-Wook Oh ◽  
So-Yeon Lee ◽  
Hyuk-Sang Jung ◽  
Yong-Joo Lee

AbstractReinforced retaining walls are structures constructed horizontally to resist earth pressure by leveraging the frictional force imparted by the backfill. Reinforcements are employed because they exhibit excellent safety and economic efficiency. However, insufficient reinforcement can lead to collapse, and excessive reinforcement reduces economic efficiency. Therefore, it is important to select the appropriate type, length, and spacing of reinforcements. However, in actual sites, although the stress and fracture mechanisms in the straight and curved sections of reinforced soil retaining walls differ, the same amount of reinforcements are typically installed. Such an approach can lead to wall collapse or reduce economic feasibility. Therefore, in this study, the behaviours of straight and curved sections fortified with reinforcements of various lengths (1, 3, 5, and 7 m) are predicted through a three-dimensional numerical analysis. The retaining walls are of the same height, but the reinforcement variations in the aforementioned sections influence the wall behaviour differently. Based on the results, the optimum reinforcement lengths for the straight and curved parts were selected. By installing reinforcements of different lengths in these sections, the maximum reinforcing effect with minimum reinforcement was derived. This study further found that the curved section of the wall required more reinforcements, and the reinforcement lengths for the curved and straight sections should be separately optimized.


2020 ◽  
Vol 10 (3) ◽  
pp. 901 ◽  
Author(s):  
Young Je Kim ◽  
Hyuk Sang Jung ◽  
Yong Joo Lee ◽  
Dong Wook Oh ◽  
Min Son ◽  
...  

Reinforced soil retaining wall are ground structures that can be readily seen all around us. The development of reinforcements to these walls and their demand have increased rapidly. These walls are advantageous because they can be used not only in simple construction compared with reinforced concrete retaining walls but also when the height of the wall needs to be higher. However, unlike reinforced concrete retaining walls, in which the walls are integrated and resist the earth pressure on the back, the block-type reinforced earth retaining wall method secures its structural stability by frictional force between the buried land and reinforcements. A phenomenon in which a block is cracked or dropped owing to deformation has been frequently reported. In particular, this phenomenon is concentrated at the curved parts of a reinforced soil retaining wall and is mainly known as a stress concentration. However, to date, the design of reinforced soil retaining walls has been limited by the two-dimensional plane strain condition and has not considered the characteristics of the curved part. There is a lack of research on curved part. Therefore, this research determines the behavioural characteristics of curved-part reinforced soil retaining walls with regard to the shape (convex or concave) and angle (60°, 90°, 120°, and 150°). The displacement generated in the straight part and the curved part was analysed through an Laboratory Scale Test. The results showed that the horizontal displacement of the curved part increases as a convex angle becomes smaller, and the horizontal displacement of the curved part decreases as a concave angle becomes smaller. At the center (D and H have the same length, but H represents the height and D represents the separation distance from the center of the curved part) of the convex curve, the horizontal displacement of the 0.5 D section decreased to 13.8%; it decreased to 41.0% in the 1.0 D section. For concave angles, it was revealed that the horizontal displacement from the center 0.0 D to the 0.5 D section of the curved part increased by 25%, and from the 1.0 D section, by 75%. It was confirmed that the displacement difference was largely based on the value of 0.5 D. It was judged that this can be used as basic data for the design and construction guidelines for reinforced soil retaining wall of reinforced soil retaining walls.


2021 ◽  
Vol 11 (6) ◽  
pp. 2744
Author(s):  
Álvaro R. Serrano-Chacón ◽  
Emilio J. Mascort-Albea ◽  
Jacinto Canivell ◽  
Rocío Romero-Hernández ◽  
Antonio Jaramillo-Morilla

Institutions such as ICOFORT (International committee on fortifications and military heritage) encourages the development of diagnosis strategies for the conservation and maintenance of historic earthen walls as highly necessary. Thus, it is important to be aware of the conditions in urban contexts, where the deterioration can be more aggressive and the risk of damage increases. Despite this, there are many strategies of constructive diagnosis for these kinds of monuments, but not many of them are concerned with the structural assessment of situations in which the ramparts work as a retaining wall in an unforeseen way. The medieval ramparts of Seville (Spain) are shown as a completely representative case study of the above-mentioned situation. In the research sector, the monument resists the lateral earth pressure developed by the new difference in height at both sides of the wall. Based on the limited states principle and on different international codes formulation, a tool was programmed to carry out automatic calculations to verify the case study’s overall stability conditions using standard sections. The obtained results were based on the overturning, bearing, and sliding overdesign factors (ODF) and determined a stable situation that could be at risk because of changes in the surrounding such as, excavations or the movements of the ground water table, or seismic events. Thus, the need and usefulness of strategies and control instruments that should be integrated into heritage intervention projects have been proved.


2021 ◽  
Vol 13 (9) ◽  
pp. 4754
Author(s):  
Muhammad Imran Khan ◽  
Mohamed A. Meguid

Expanded polystyrene (EPS) geofoam is a lightweight compressible material that has been widely used in various civil engineering projects. One interesting application of EPS in geotechnical engineering is to reduce the lateral earth pressure on rigid non-yielding retaining walls. The compressible nature of the EPS geofoam allows for the shear strength of the backfill soil to be mobilized, which leads to a reduction in lateral earth pressure acting on the wall. In this study, a finite element model is developed and used to investigate the role of geofoam inclusion between a rigid retaining wall and the backfill material on the earth pressure transferred to the wall structure. The developed model was first calibrated using experimental data. Then, a parametric study was conducted to investigate the effect of EPS geofoam density, relative thickness with respect to the wall height, and the frictional angle of backfill soil on the effectiveness of this technique in reducing lateral earth pressure. Results showed that low-density EPS geofoam inclusion provides the best performance, particularly when coupled with backfill of low friction angle. The proposed modeling approach has shown to be efficient in solving this class of problems and can be used to model similar soil-geofoam-structure interaction problems.


2021 ◽  
Vol 11 (18) ◽  
pp. 8681
Author(s):  
Xiaoguang Cai ◽  
Shaoqiu Zhang ◽  
Sihan Li ◽  
Honglu Xu ◽  
Xin Huang ◽  
...  

Most of the damage to reinforced retaining walls is caused by excessive deformation; however, there is no calculation method for deformation under static and dynamic loads in the design codes of reinforced soil retaining walls. In this paper, by collecting the measured displacement data from four actual projects, four indoor prototype tests and two indoor model tests under a total of 10 static load conditions, and comparing the calculation results with seven theoretical methods, the results show that the FHWA method is more applicable to the permanent displacement prediction of indoor prototype tests and that the CTI method is more applicable to the permanent displacement prediction of actual projects and indoor model tests. Two yield acceleration calculation methods and four permanent displacement calculation formulas were selected to calculate the displacement response of two reinforced soil test models under seismic loads and compared with the measured values, and the results showed that the Ausilio yield acceleration solution method was better. When the input peak acceleration ranges from 0.1 to 0.6 g, the Richards and Elms upper limit method is used, and when the input peak acceleration is 0.6–1.0 g, the Newmark upper limit method can predict the permanent displacement of the retaining wall more accurately.


2018 ◽  
Vol 2 (2) ◽  
pp. 86
Author(s):  
Mila K. Wardani ◽  
Felicia T. Nuciferani ◽  
Mohamad F.N. Aulady

Landslide one of the natural disasters that caused many victims. Therefore, the landslide need a construction that can withstand landslide force. This study aims to plan retaining walls to prevent landslides in the farm area in Kandangan Subdistrict, Kediri Regency. The method used is to use slide analysis which is used to plan the retaining wall. In addition the planning of soil containment walls u ses several methods as a comparison. The results of this study indicate that the planning of ordinary soil retaining walls is still not enough to overcome slides. The minimum SF value that meets the safe limit of landslide prevention is 1.541 in the combination of 1/3 H terracing and the number of gabions as many as 7 with a total height of 2- 3 m .


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