Soil Retaining Wall Research Articles

Enhancements in image quality and block detection performance for Reinforced Soil-Retaining Walls under various illuminance conditions

To ensure continuous monitoring of reinforced soil-retaining walls (RSWs) even under low-illuminance conditions, such as during the night, it is imperative to evaluate the performance of deep learning-based detection. In this study, we constructed a laboratory RSW model and generated a dataset with varying illuminance levels to assess the impact of image enhancement and block detection. Various image enhancement methods were applied to improve image quality and evaluate their effect on deep learning. RGB optimization (RO) was proposed to optimize RGB intensity and compared with gamma correction, histogram equalization, and low-light image enhancement with illumination map estimation. RO demonstrated outstanding image enhancement performance, as evidenced by lightness order error, peak signal-to-noise ratio, and structural similarity index measure, ensuring high image quality. The trained RO model using Mask R-CNN exhibited excellent accuracy, recall, and F1 score, delivering remarkable detection performance under low illuminance conditions, resulting in a 7.44 % improvement in the F1 score. Image enhancement techniques that maintain similarity, such as lightness order error and structural similarity, across varying illuminance conditions contribute to enhancing the block detection performance of Mask R-CNNs.

Experimental Study on Mechanical Properties of Reinforced Soil and Frame Beam Anchor Combination System

To address issues with excessive displacement, deformation, and insufficient load bearing capacity in high-fill-reinforced soil-retaining walls, a novel reinforced soil–frame anchor combination system was developed. Despite the limited existing research on its mechanical properties and synergy, a physical model test was conducted to investigate the system’s behavior. The test focused on the horizontal displacement of the frame beam wall, grid strain, wall back earth pressure, and anchor strain. Results indicated that anchor prestress effectively controlled horizontal deformation, limiting it to 65% of the original displacement value. Additionally, as the top load increased, strain in the bottom bars showed minor changes, while strain in the middle and upper bars exhibited significant sensitivity to load variations. The application of anchor prestress reduced strain in each reinforcement layer, enhancing the geogrid’s load bearing capacity. Furthermore, anchor prestress altered the distribution of earth pressure within the system, establishing a synergistic relationship between reinforced soil and frame beam anchors. This stress transfer mechanism improved overall system performance, as demonstrated in the test. Overall, the study confirmed the benefits and superior performance of the combined system.

Numerical analysis of the working performance of ring combination reinforced retaining wall

In this study, a new combined reinforcement structure suitable for reinforced soil-retaining walls is proposed. FLAC 3D finite element software was used to establish three-dimensional numerical models of reinforced soil retaining walls with different forms of reinforcement, and the effects of reinforced rings on the mechanical and deformation characteristics of retaining walls, as well as the mechanism of the reinforced rings working with horizontal geogrids, were investigated. The test results verified the superiority of the ring combination-reinforced structure in bearing and deformation under the same loading conditions. Moreover, the ring combination-reinforced soil retaining wall exhibited a stronger ability to resist deformation than the horizontal-reinforced soil retaining wall.

Smoothed Particle Hydrodynamics (SPH) Analysis of Slope Soil–Retaining Wall Interaction and Retaining Wall Motion Response

The occurrence of slope instability disasters seriously endangers the safety of people’s lives and property in China. Therefore, it is essential to study the slope instability process and the interaction between soil and retaining walls. In this paper, the smoothed-particle hydrodynamics (SPH) method, based on the elastoplastic constitutive model of rock and soil, was used to simulate the entire process of slope instability and the interaction between soil and retaining walls. The model, based on the classical elastic–plastic theory, includes linear elastic deformation and plastic deformation following the non-associated flow rule under the Drucker–Prager (DP) yield criterion. By considering the plastic characteristics of geotechnical materials, this method can accurately simulate the slope movement process. The model was established, calculated, and compared with a slope example, thus verifying its feasibility. Furthermore, the motion response of the retaining wall under different conditions was studied, which provides a new numerical simulation platform for the stability checking of the retaining wall and motion analysis after the interaction between the retaining wall and slope soil.

Time-History Dynamic Characteristics of Reinforced Soil-Retaining Walls

Time-History Dynamic Characteristics of Reinforced Soil-Retaining Walls

Trends and characteristics of the LEAP 2020 Soil-Retaining Wall response

Trends and characteristics of the LEAP 2020 Soil-Retaining Wall response

Long-Term Performance Assessment of a Geosynthetic-Reinforced Railway Substructure

Significant savings in carbon emissions, cost, and time could be achieved via the reduction in maintenance frequency, capital costs of track construction, and land used. Geosynthetic-reinforced soils offer such sustainable solutions. The experimental work presented in this paper investigates the long-term performance of a Geosynthetic-Reinforced Soil Retaining Wall (GRS-RW) system as an alternative to the conventional railway embankment. Full-scale testing was carried out on three sleeper sections of ballasted and slab tracks by simulating train loads cyclically, phased to 360 km/h. The tracks were supported by either a low-level fully confined conventional embankment or a GRS-RW substructure. The substructures were formed of a 1.2 m deep subgrade and frost protection layer, in accordance with high-speed railway design standards. The overall aim was to assess the performance of the tracks, in terms of transient displacements and total settlements. It was observed that once the GRS-RW system reached its active state, it deformed in a very similar way to a conventional embankment despite the fact that the GRS-RW system is less confined than the conventional embankment. The results indicate that the cumulative settlement of the slab track, which is due to the plastic deformation of the soil, is significantly less than that of the ballasted track, which is primarily caused by the movement of the ballast particles.

Dynamic Characteristics of Reinforced Soil Retaining Wall with Composite Gabion Based on Time Domain Identification Method

A series of shaking table tests was carried out on the dynamic performance and working mechanism of a gabion reinforced soil retaining wall under seismic load. The test results show that the panel presents the deformation mode of middle and upper bulging at the contact point between the rigid box and the retaining wall The settlement of top backfill is relatively uniform, and there is basically no differential settlement, the natural frequencies at different positions and heights inside the retaining wall are basically the same, and the natural frequencies are stable between 22.61 and 23.04 Hz below 0.8 g. The damping ratio decreases with the increase in wall height, and the damping ratio at each stage after vibration is greater than that before vibration. The seismic earth pressure is nonlinearly distributed. The measured value of the lower part of the retaining wall is smaller than that calculated by the Seed–Whitman method with an increase in peak acceleration, and the measured value of the upper part of the retaining wall is larger than the theoretical calculation results. The position of the resultant action point of seismic earth pressure is greater than 0.33 times the wall height specified by the Mononobe–Okabe method.

Numerical and Analytical Analysis of the Surcharge Application Distance influence on the Behavior of Reinforced Soil Retaining Wall

Numerical and Analytical Analysis of the Surcharge Application Distance influence on the Behavior of Reinforced Soil Retaining Wall

Experimental study on FBG sensing technology-based stress monitoring at the corners of reinforced soil retaining walls.

As a unique type of flexible slope fill-retaining structure, reinforced soil-retaining walls have the advantages of convenient construction, broad application conditions, good seismic performance, and high economic benefits. In general, reinforced soil-retaining walls appear at corners due to the restriction in topographic conditions during engineering construction. However, their special structures and stress conditions are usually ignored, thus triggering panel bulging, cracking, and collapse. In this study, an experimental method based on fiber Bragg grating (FBG) sensing technology was proposed for a physical model of reinforced soil-retaining walls. Then, a uniformly distributed load experiment was performed on this model by combining the measurement advantages of intelligent wire-type soil pressure sensors and the flexible characteristics of geotechnical reinforcement materials. The deformation development of this reinforced soil-retaining wall was monitored. Results revealed that before and after the loading of the reinforced soil-retaining wall, the deformation was mainly concentrated above the retaining wall, and the deformation scale at the corners was larger than that in the bilateral linear parts. After loading, the largest force deformation area on the retaining wall was transferred from the corners to the load area. The maximum strain was right beneath the load above the retaining wall, and the peak value at the other layers gradually approached the retaining wall. The experimental results prove that FBG sensing technology is feasible and effective for the whole-process monitoring of reinforced soil-retaining walls and is thus worthy of popularization and application.

Analytical Solutions for Internal Stability of a Geosynthetic-Reinforced Soil Retaining Wall at the Limit State

Analytical Solutions for Internal Stability of a Geosynthetic-Reinforced Soil Retaining Wall at the Limit State

Analysis of the Working Response Mechanism of Wrapped Face Reinforced Soil Retaining Wall under Strong Vibration

A series of shaking table tests were carried out to explore the dynamic characteristics and working mechanisms of wrapped-face reinforced soil-retaining walls under strong vibration. Under the 0.1–1.0 g horizontal peak ground acceleration (HPGA), the damping ratio of sand shows a downward trend as a whole, so the acceleration amplification coefficient decreases with the increase of HPGA. However, when HPGA reaches 1.0 g, the acceleration amplification coefficient increases; the range of acceleration amplification coefficient at the top of the wall is 1.69–1.36. When HPGA is 1.0 g, the maximum cumulative residual displacement of the panel is 2.96% H, and the maximum uneven settlement of the sand is 3.57% H, both of which have exceeded the limit of the specification. With the increase of HPGA, the ratio of the dynamic earth force increment to the total dynamic earth force gradually approaches 50%. Since the reinforcement effect of geogrid is not considered, the predicted value of traditional earth pressure theory is different from the measured value. According to the Washington State Department of Transportation displacement index, the deformation range of wrapped-face reinforced soil-retaining walls is divided into three stages: the quasi-elastic stage, the plastic stage, and the failure stage.

National Road Slide Management With Cantilever Type Soil Retaining Wall

The title of this research is "National Road Avalanche Management With Cantilever Type Soil Retaining Wall". The background of the research is that the national road sta 20+700, section 041 or to be precise in Muaramais Village, Tambangan District, Mandailing Natal Regency, North Sumatra, is a landslide point that occurred around 2018. For this reason, in 2021, handling has been carried out in landslides with a cantilever type retaining wall. The dimensions of the cantilever are 15 meters long, 3.50 meters deep from the asphalt surface and 2.00 meters wide. Then, the upper wall thickness is 0.30 meters and the lower wall thickness is 0.40 meters. The purpose of this study was to calculate whether the cantilever type retaining wall is safe against overturning, sliding and soil bearing capacity. The results of the research, that the cantilever type retaining wall is safe against overturning, because FS rolls = 4.65 ≥ FS = 2.00 and stability against shear is also safe, because FS shear = 1.96 ≥ FS = 1.50 and retaining walls safe against the bearing capacity of the soil, because the bearing capacity FS = 9.30 ≥ FS = 3.00

National Road Slide Management With Cantilever Type Soil Retaining Wall

The title of this research is "National Road Avalanche Management With Cantilever Type Soil Retaining Wall". The background of the research is that the national road sta 20+700, section 041 or to be precise in Muaramais Village, Tambangan District, Mandailing Natal Regency, North Sumatra, is a landslide point that occurred around 2018. For this reason, in 2021, handling has been carried out in landslides with a cantilever type retaining wall. The dimensions of the cantilever are 15 meters long, 3.50 meters deep from the asphalt surface and 2.00 meters wide. Then, the upper wall thickness is 0.30 meters and the lower wall thickness is 0.40 meters. The purpose of this study was to calculate whether the cantilever type retaining wall is safe against overturning, sliding and soil bearing capacity. The results of the research, that the cantilever type retaining wall is safe against overturning, because FS rolls = 4.65 ≥ FS = 2.00 and stability against shear is also safe, because FS shear = 1.96 ≥ FS = 1.50 and retaining walls safe against the bearing capacity of the soil, because the bearing capacity FS = 9.30 ≥ FS = 3.00

Performance of Modular-Reinforced Soil-Retaining Walls for an Intercity Railway during Service

In order to investigate the mechanical behavior of reinforced soil-retaining walls during service, this paper carried out a long-term remote observation test for 6 years on the modular-reinforced soil-retaining wall of the Qingrong intercity railway in eastern China’s Shandong Province. During the construction period, earth pressure boxes, flexible displacement meters, settlement pipes and displacement meters were buried to observe the soil pressure, reinforcement strain, horizontal displacement and settlement of the reinforced earth-retaining wall, respectively, for a long time; then, the results were analyzed to summarize its variation law. The results show that the reinforced earth-retaining wall was stable after one year of construction. It was determined that the strain of reinforcement in each layer decreased with time, culminating in a value of less than 0.88 percent during the 6th year. The maximum horizontal displacement of the wall was 11.43 mm and the maximum settlement of the wall top was 46.77 mm, which were 0.15% and 0.60% of the wall height, respectively. These research results can be applied to the construction and design of reinforced soil-retaining walls in high-speed railways. The effects of the elastic modulus of filler, the tensile modulus of reinforcement and the reinforcement length on the characteristics of the retaining wall were analyzed in the numerical simulation with PLAXIS2D. The results and analysis show: the elastic modulus of filler and reinforcement length have a significant effect on the horizontal displacement of the retaining wall. The results of this experiment can be referenced for engineering projects.

Performance Evaluation of Feature Matching Techniques for Detecting Reinforced Soil Retaining Wall Displacement

Image registration technology is widely applied in various matching methods. In this study, we aim to evaluate the feature matching performance and to find an optimal technique for detecting three types of behaviors—facing displacement, settlement, and combined displacement—in reinforced soil retaining walls (RSWs). For a single block with an artificial target and a multiblock structure with artificial and natural targets, five popular detectors and descriptors—KAZE, SURF, MinEigen, ORB, and BRISK—were used to evaluate the resolution performance. For comparison, the repeatability, matching score, and inlier matching features were analyzed based on the number of extracted and matched features. The axial registration error (ARE) was used to verify the accuracy of the methods by comparing the position between the estimated and real features. The results showed that the KAZE method was the best detector and descriptor for RSWs (block shape target), with the highest probability of successfully matching features. In the multiblock experiment, the block used as a natural target showed similar matching performance to that of the block with an artificial target attached. Therefore, the behaviors of RSW blocks can be analyzed using the KAZE method without installing an artificial target.

Determination of the Effect of Sidewall Friction in Reinforced Soil Retaining Wall Experiments

Abstract A simple approach to estimate sidewall friction in reinforced soil model experiments conducted in parallel-sided test boxes with unlubricated walls is proposed. Analytical solutions are developed for reinforced soil slopes and retaining walls subjected to self-weight or external loading. It turns out that the frictional effect depends on the shape of the failure zone and the value of friction coefficient between soil and a sidewall material. The theoretical predictions were verified in laboratory experiments in a test box with lubricated and unlubricated sidewalls. It was shown that the method can be used to estimate sidewall friction not only under failure conditions, but also under all stages of surcharging prior to failure.

Earthquake Response of Connected and Unconnected Back-to-Back Geosynthetic-Reinforced Soil Walls

A two-dimensional finite-element analysis based on PLAXIS 2D was used to study the behavior of connected and unconnected back-to-back mechanically stabilized earth walls under earthquake loading. The numerical model was first validated with the results from the full-scale dynamic centrifuge tests on reinforced soil-retaining walls. The behavior of connected and closely spaced unconnected back-to-back mechanically stabilized earth walls (BBMSE) was compared in terms of tensile forces mobilized in geogrids, and the lateral earth pressures and maximum displacements of the wall. The total seismic earth thrusts at the end of the reinforced zone and at the facing of BBMSE walls and their points of application were presented. These results were compared with the widely used Mononobe–Okabe method. The connected walls were found to significantly reduce the dynamic loads on the walls compared with those on unconnected walls.

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

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.

Shaking Table Study on the Seismic Performance of Geogrid Reinforced Soil Retaining Walls

This study presents experimental results from shaking table tests on a reduced-scale geogrid reinforced soil retaining wall (RSRW) to investigate the seismic response of the fundamental frequency, acceleration amplification, face displacement, backfill surface settlement, and reinforcement strain under different peak accelerations and durations. The fundamental frequency is in good agreement with the predicted values. The root mean square (RMS) acceleration amplification factors increase nonlinearly with the wall height and decrease with increasing seismic load, which is not regarded as a constant value. The distributions of the peak displacement are consistent with those of the residual displacement. The combination of the sliding and rotation is observed as the predominant mode of displacement, and the rotation mode is dominant. The positions near the face (35 cm) and the ends of the reinforcement (140 cm) demonstrated larger settlement than that of the central position (70 cm and 105 cm). The reinforcement strain increased with increasing peak acceleration and maximum values measured at the central layers. The trends of the potential failure surface are similar to those of the 0.3H bilinear failure surface. The friction coefficient is nonlinearly distributed along with the reinforcements, and the maximum friction coefficient appears at the top layer (F11).