Behavior of a welded wire wall with poor quality, cohesive–friction backfills on soft Bangkok clay: a case study

1991 ◽  
Vol 28 (6) ◽  
pp. 860-880 ◽  
Author(s):  
D. T. Bergado ◽  
R. Shivashankar ◽  
C. L. Sampaco ◽  
M. C. Alfaro ◽  
L. R. Anderson
Keyword(s):  
Key Words ◽  
Soft Clay ◽  
Poor Quality ◽  
Mechanically Stabilized Earth ◽  
Mse Wall ◽  
Overall Performance ◽  
Stiff Clay ◽  
Mechanically Stabilized ◽  
Grid Reinforcement

A full-scale and extensively instrumented experimental mechanically stabilized earth (MSE) wall with steel grid reinforcements was built on soft clay foundation. Three different locally available poor to marginal quality backfills were used in each of three sections along its length. The soft Bangkok clay in the subsoil is about 6 m thick, overlain by a surficial 2 m thick weathered clay crust and underlain by a layer of stiff clay. It was observed that the amount of subsoil movement greatly influenced the variation in the vertical pressure beneath the wall, as well as the tension in the reinforcement. Pullout resistances in the field were also found to be very much affected by the arching effects due to the presence of inextensible reinforcement in combination with the subsoil movements. The wall showed no signs of instability both during construction and in the postconstruction phases, despite the large settlements and lateral movements. Its overall performance has been satisfactory. It was concluded that the steel grid reinforcement can be effectively used to reinforce poor to marginal quality backfill in walls and embankments on soft clay foundations. Key words: mechanically stabilized earth, inextensible reinforcements, soft clay foundation, poor quality backfills, base pressures, settlements, lateral movements, lateral pressures, compaction, arching.

Temperature Distribution in Mechanically Stabilized Earth Wall Soil Backfills for Design Under Elevated Temperature Conditions

2015 ◽  
Vol 7 (2) ◽  
Author(s):  
Andrew M. Kasozi ◽  
Raj V. Siddharthan ◽  
Rajib Mahamud
Keyword(s):  
Las Vegas ◽  
Temperature Data ◽  
Measured Temperature ◽  
Mechanically Stabilized Earth ◽  
Ansys Fluent ◽  
Design Procedures ◽  
Model Predictions ◽  
Mse Wall ◽  
Mechanically Stabilized Earth Wall ◽  
Mechanically Stabilized

Two-dimensional (2D) transient numerical thermal modeling was undertaken using ansys fluent v12.1 software to estimate distribution of soil backfill temperatures in a typical mechanically stabilized earth (MSE) wall. The modeling was calibrated using field-measured temperature data from the Tanque-Verde MSE wall in Tucson, Arizona (AZ) in which computed temperature data were found to be within ±5% of the field data. The calibrated model predictions for Las Vegas, Nevada (NV) showed an overall average soil backfill temperature of 34.3 °C relative to a maximum outside surface temperature of 51.6 °C. Such a high average soil backfill temperature calls for modification of design procedures since conventional designs are based on geosynthetic tensile strength determined at 20 °C.

scholarly journals Mechanically Stabilized Earth with Steel Reinforcement

2021 ◽  
Vol 9 (3) ◽  
pp. 135-141
Author(s):  
Magdi M. E. Zumrawi ◽  
Abubaker B. B. Barakat ◽  
Idris M. I. Abdalla ◽  
Rabab A. A. Altayeb
Keyword(s):  
Retaining Wall ◽  
Soil Reinforcement ◽  
Current Status ◽  
Mechanically Stabilized Earth ◽  
Steel Strips ◽  
Wall Structures ◽  
Backfill Soil ◽  
Mse Walls ◽  
Mechanically Stabilized

This paper presents the Mechanically Stabilized Earth (MSE) technique as a practical option for earth retaining wall structures. The literature pertaining soil reinforcement methods and their application in MSE walls were intensively reviewed. The present work focused on evaluating the performance of MSE walls with backfill soil reinforced by steel strips. Almolid square overpass bridge in Khartoum, which was constructed in 2015 with MSE walls as lateral support of the overpass ramps, was considered as case study. Based on field observations, the current status of the overpass bridge has proven that the use of MSE walls is successful and beneficial for sustainability of the overpass.  

Crash Wall Design to Protect Mechanically Stabilized Earth Retaining Walls

2013 ◽  
Vol 2377 (1) ◽  
pp. 49-60
Author(s):  
Akram Y. Abu-Odeh ◽  
Kang-Mi Kim
Keyword(s):  
Structural Damage ◽  
Retaining Wall ◽  
Retaining Walls ◽  
Wall Structure ◽  
Mechanically Stabilized Earth ◽  
Element Analysis ◽  
Wall Panels ◽  
Mse Wall ◽  
Mechanically Stabilized ◽  
Earth Fill

Mechanically stabilized earth (MSE) retaining walls are used to provide roadway elevation for bridge approaches, underpass frontage roads, and other roadway elevation applications. Vehicular traffic may exist on the high (fill) side of the MSE retaining wall, the low side, or both sides. For traffic on the high side, a conventional traffic barrier might be placed on or near the top of the wall and mounted on a moment slab or a bridge deck. For traffic on the low side, a conventional traffic barrier might be installed adjacent to the wall or the wall itself may serve as the traffic barrier. Typical MSE wall panels are not designed to resist vehicle impacts. Therefore, structural damage to the wall panels and the earth fill would require complicated and expensive repairs. A simple reinforced-concrete crash wall constructed in front of the MSE wall panels could significantly reduce damage to the panels. It might prove practical to implement such a design to reduce costly repairs to the MSE wall structure. In this paper, LS-DYNA finite element analysis code was used to model and analyze a sacrificial crash wall design to determine its effectiveness in protecting an MSE retaining wall. Based on the LS-DYNA simulations, a crash wall that is 8 in. (0.2 m) thick is considered to be an adequate design to reduce damage to the MSE wall.

scholarly journals Reliability-based design of internal limit states for mechanically stabilized earth walls using geosynthetic reinforcement

2019 ◽  
Vol 56 (6) ◽  
pp. 774-788 ◽  
Author(s):  
Richard J. Bathurst ◽  
Peiyuan Lin ◽  
Tony Allen
Keyword(s):  
Reliability Index ◽  
Limit State ◽  
Closed Form Solution ◽  
Form Solution ◽  
Design Practice ◽  
Mechanically Stabilized Earth ◽  
Limit States ◽  
Reliability Based Design ◽  
Mechanically Stabilized

This paper demonstrates reliability-based design for tensile rupture and pullout limit states for mechanically stabilized earth (MSE) walls constructed with geosynthetic (geogrid) reinforcement. The general approach considers the accuracy of the load and resistance models that appear in each limit state equation plus uncertainty due to the confidence (level of understanding) of the designer at the time of design. The reliability index is computed using a closed-form solution that is easily implemented in a spreadsheet. The general approach provides a quantitative link between nominal factor of safety, which is familiar in allowable stress design practice, and reliability index used in modern civil engineering reliability-based design practice. A well-documented MSE wall case study is used to demonstrate the general approach and to compare margins of safety using different load and resistance model combinations. A practical outcome from the case study example is the observation that the pullout limit state is much less likely to control design than the ultimate tensile rupture state for walls with continuous reinforcement coverage. The more accurate “simplified stiffness method” that is used to compute tensile loads in the reinforcement under operational conditions is shown to generate a more cost-effective reinforcement option than the less accurate American Association of State Highway and Transportation Officials (AASHTO) simplified method.

Pullout Resistance Factors for Inextensible Mechanically Stabilized Earth Reinforcements in Sandy Backfill

2013 ◽  
Vol 2363 (1) ◽  
pp. 21-29 ◽  
Author(s):  
William D. Lawson ◽  
Priyantha W. Jayawickrama ◽  
Timothy A. Wood ◽  
James G. Surles
Keyword(s):  
Large Scale ◽  
Steel Strip ◽  
Mechanically Stabilized Earth ◽  
Overburden Pressure ◽  
Welded Steel ◽  
Pullout Resistance ◽  
Resistance Factors ◽  
Granular Fill ◽  
Mechanically Stabilized ◽  
Grid Reinforcement

This paper presents results from a laboratory program of 402 pullout tests of inextensible reinforcements used for walls of mechanically stabilized earth (MSE). Results focus on the evaluation of pullout resistance factors for ribbed-steel strip and welded-steel grid reinforcements embedded in sandy backfill that marginally met AASHTO requirements for select granular fill. This project used Texas Tech University's large-scale MSE test box with dimensions of 12 3 12 3 4 ft and an applied overburden capacity of 40 ft of backfill. This test box facilitated pullout testing at a scale not unlike typical field construction. The research design evaluated pullout resistance factors for both ribbed-strip and welded-grid reinforcements for a variety of independent variables, including overburden pressure, reinforcement length, level of compaction, grid wire size, and grid geometry, such as transverse and longitudinal wire spacing. Appropriate statistical analyses were used to interpret the data within the context of published AASHTO design guidance for inextensible MSE reinforcements. The results show that pullout behaviors of both ribbed strips and welded grids in properly compacted sandy backfill are conservative compared with the default pullout resistance factors provided by AASHTO. The data also suggest that the current AASHTO equations for pullout resistance factors for grid reinforcement do not accurately capture the influence of transverse and longitudinal bar spacings.

scholarly journals STUDY OF BEHAVIOR MECHANICALLY STABILIZED EARTH WALL (MSE-WALL) WITH SAND ON THE MODEL TEST IN THE LABORATORY

CERUCUK ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 87
Author(s):  
Ainun Mawa'dah Noor
Keyword(s):  
Maximum Load ◽  
Lateral Stress ◽  
Mechanically Stabilized Earth ◽  
Final Project ◽  
Mse Wall ◽  
Technological Developments ◽  
Mechanically Stabilized Earth Wall ◽  
Mechanically Stabilized ◽  
Main Components ◽  
Lateral Reinforcement

Different types of field conditions coupled with rapid technological developments gave birth to innovations in the construction of retaining walls. One type of landslide deterrence construction that began to be developed in Indonesia is the Mechanically Stabilized Earth Wall or often called the MSE wall. The main components of the MSE wall are backfill material, lateral reinforcement and facing panel. In this final project, research will be conducted to observe the behavior of MSE wall systems on a laboratory scale.The study was conducted by planning the innovation of the facing panel form and the variation in the number of reinforcement layers. The variations of reinforcement are 1 layer, 2 layers, 3 layers, 4 layers and without reinforcement. The reinforcement used is sack as a substitute for geotextile woven with selected pile material is sand. In testing the prototype of the MSE wall, a dial gauge is used to find out the deformation, while for loading it uses a jack-push tool.From these tests, the data obtained in the form of shifts, lateral stresses, and the maximum load of the results of the study showed that the application of reinforcement can affect the amount of lateral stress, shifting, and load. The minimum lateral stress is 0.023 kg/cm2 and the maximum load that can be held by the MSE wall is 75 kg.

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