Influence of Inadequate Compaction near Facing on Construction Response of Wrapped-Face Mechanically Stabilized Earth Walls

2008 ◽  
Vol 2045 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Kianoosh Hatami ◽  
Alan F. Witthoeft ◽  
Lindsay M. Jenkins
Keyword(s):  
Structural Damage ◽  
Lateral Displacement ◽  
Friction Angle ◽  
Mechanically Stabilized Earth ◽  
Mechanically Stabilized Earth Walls ◽  
Heavy Equipment ◽  
Mse Wall ◽  
Mse Walls ◽  
Wall Models ◽  
Mechanically Stabilized

Standard practice for the compaction of backfill soil near the facing of a mechanically stabilized earth (MSE) wall or embankment is to use lightweight compaction equipment to prevent excessive facing deformation. Complications caused by compaction with heavy equipment near the facing could also include misalignment or structural damage of the wall facing and overstressing of the reinforcement layers. However, inadequate compaction near the facing could result in later settlement or appearance of voids behind the facing. Little research has been reported in the literature to quantify the effects of loosely compacted soil behind the facing on the stability and serviceability of MSE walls at the end of construction. The influence of inadequate compaction effort near the facing on the construction performance of idealized wrapped-face MSE wall models was investigated by using a numerical simulation approach. It was shown that inadequate backfill compaction within 1 m of the wall facing could increase the wall lateral displacement by about 40% and the reinforcement strains by about 90% compared with the response of an otherwise identical (i.e., control) wall model constructed with uniform compaction throughout the backfill. This effect was found to be more significant for higher-quality backfills with greater friction angle values and less stiff reinforcement materials. Results of this study on idealized wrapped-face wall models highlight the importance of proper soil compaction and quality control near the facing of MSE walls and offer example quantitative increases that could be expected in the out-of-alignment and reinforcement loads in these MSE structures.

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.

A Model for Estimating Resistivity of In-Service Backfill of Mechanically Stabilized Earth Walls Based on Minimum Resistivity and Degree of Saturation

2019 ◽  
Vol 2673 (2) ◽  
pp. 502-508
Author(s):  
Jose Luis Arciniega ◽  
W. Shane Walker ◽  
Soheil Nazarian ◽  
Kenneth L. Fishman
Keyword(s):  
Moisture Content ◽  
Degree Of Saturation ◽  
Mechanically Stabilized Earth ◽  
Resistivity Measurements ◽  
Mechanically Stabilized Earth Walls ◽  
Moisture Contents ◽  
Mse Walls ◽  
Mechanically Stabilized ◽  
Earth Walls

The resistivity of aggregates used as fill within mechanically stabilized earth (MSE) walls has been found to be a good indicator of its potential to corrode metal reinforcements. As such it is important to accurately measure the fill resistivity. Previous studies have found that resistivity is affected by the gradation of the material, as finer particles normally have much lower resistivity than coarse particles. The resistivity is also greatly dependent on moisture content. To estimate how the variation in moisture content can affect the resistivity, and the in-service performance of MSE walls, laboratory resistivity measurements were performed on 23 materials at varying moisture contents. The results were used to develop a model to estimate the resistivity of a given material knowing its minimum resistivity, porosity, and degree of saturation greater than 50%. Model predictions can potentially be used to estimate the resistivity of in-service wall fill and to harmonize field and laboratory resistivity measurements. The model could be used in future corrosion modeling that considers the seasonal or long-term moisture contents of the fill, similar to the recently developed Mechanistic Empirical Pavement Design (MEPDG) procedure.

scholarly journals Numerical Study of the Behavior of Back-to-Back Mechanically Stabilized Earth Walls

Geotechnics ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 18-37
Author(s):  
Seyed Hamid Lajevardi ◽  
Khashayar Malekmohammadi ◽  
Daniel Dias
Keyword(s):  
Numerical Study ◽  
Failure Surface ◽  
Friction Angle ◽  
Soil Reinforcement ◽  
Mechanically Stabilized Earth ◽  
Surface Shear ◽  
Mechanically Stabilized Earth Walls ◽  
Critical Failure Surface ◽  
Mechanically Stabilized ◽  
Earth Walls

Back-to-back mechanically stabilized earth (MSE) walls can sustain significant loadings and deformations due to the interaction mechanisms which occur between the backfill material and reinforcement elements. These walls are commonly used in embankments approaching bridges, ramps, and railways. The performance of a reinforced wall depends on numerous factors, including those defining the soil, the reinforcement, and the soil/reinforcement interaction behavior. The focus of this study is to investigate the behavior of back-to-back mechanically stabilized earth walls considering synthetic and metallic strips. A two-dimensional finite difference numerical modeling is considered. The role of the soil friction angle, the distance of the reinforcement elements, the walls’ width to height ratio, and the quality of the soil material are investigated in a parametric study. Their effects on the critical failure surface, shear displacements, wall displacements, and tensile forces on the reinforcements are presented. The interaction between back-to-back reinforced walls strongly depends on the distance between walls and modifies the critical failure surface location.

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.

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