Earth Berms Research Articles

Case Study: Extension of MSW landfill with reinforced earth berm

This paper reports a case study of an extension design of an existing municipal solid waste (MSW) earth berm in Guangzhou, China. The berm has limited space for extension and was constructed during a rainy season. Due to the space constraint, the extended berm was designed with a steep slope 1.1 horizontal to 1.0 vertical (1.1H:1.0 V). Due to the rainy season, the new extended earth berm was built with a mix of gravel and sandy clay (i.e. Vgravel/Vclay = 50:50). To make the new berm design satisfies the stability requirement, it has been reinforced with geotextile layers within the berm and piles at the toe of the berm. A 2D finite-element analysis has been conducted to demonstrate the rationality of the design. The performance of the new berm was monitored using field sensors, which include the vertical and lateral displacements of the berm, vertical earth pressure of the berm, and tensile strain of the geotextile layers during and after the berm construction. Numerical and field tests results show that the failure surface appears along the interface between the old berm and the horizonal displacements are mainly observed in the new berm. The results of this study proven that a steep slope berm with geotextiles reinforcement can resistant the load from extended MSW landfill, which can provide a guidance for the design and construction of the extension of MSW landfill.

Theoretical analysis on influence factors of anchor cable internal force under over-excavation considering earth berm

Theoretical analysis on influence factors of anchor cable internal force under over-excavation considering earth berm

Numerical Simulation and Field Test of the Interaction between Existing Station and Enclosure in Open Excavation and Adding Stories Construction

When constructing open excavation and adding stories on the upper part of an existing station structure, the new foundation pit contacts with the existing station at zero distance; subsequently, the construction has a greater impact than that of other close constructions. To explore the cross-impact of new and existing structures on open excavation and story-adding above the existing station, in this study, through numerical simulation and field measurement, we analyze the deformation law of the existing station and foundation pit retaining structure in the excavation and story-adding construction above the existing station. The following conclusions are obtained. The excavation of the upper foundation pit leads to the overall uplift of the existing station, and the sidewall exhibits an internal extrusion trend, which is caused by an increase in the horizontal load on the station caused by the unloading of the vault and expansion of the formation plastic zone. Affected by the existing station structure, some foundation pit retaining structures are end-suspended piles; the bottoms of the end-suspended pile slips are evident. This study offers control measures for the primary support connection between the pile bottom and initial retention and protection of the existing station, deep hole grouting reinforcement of the stratum behind the pile, and reserving earth berm at the pit bottom to reduce the deformation of the end-suspended pile. The research results can provide a reference for constructing the added story of a subway transfer station.

Determination of Insertion Loss of noise barriers in Spanish roads

The evaluation of the effectiveness of noise barriers have addressed, in some research studies, the intrinsic characteristics of barriers, such as noise absorption or transmission; in other studies, it has been based on the global characteristics of Insertion Loss (IL), which is defined as the difference in the noise level before and after the installation of the barrier. IL is an extrinsic characteristic of noise barriers, depending largely on the site in which the barrier is placed. This research investigated the in situ effectiveness of existing noise barriers by using the indirect IL method established in the international standard ISO 10847:1997. Measurements were performed at thirty sample sites, distributed among the three most frequent types of material found on Spanish roads (earth berms and concrete and metal walls).The results revealed moderate IL values. Results at a distance of 25 m were clearly below the expected effectiveness of a noise barrier. The IL values for the three types of barriers were similar. The best noise reduction effect was in the frequency range of 125–8000 Hz, at which the traffic noise is dominant. In most cases, the dimensions of the barriers did not seem to have been determined taking into account diffraction requirements.

The Performance of a Low Berm in Reducing Traffic Noise

Traffic noise measurements were made behind a low, earth berm and in an adjacent open field to estimate insertion loss. The traffic was comprised of a mix of light vehicles, heavy trucks, and some medium trucks. The berm had a height of 1.65 meters above the roadway and began at the outside shoulder of a four-lane highway along U.S. Highway 101 in Northern California. Two microphone positions were located on the far side of the berm at distances of 28 and 40 meters from the center of the near lane of vehicular traffic. Away from the berm, a microphone was placed in an open field at 28 meters from the highway at a site upstream of the berm. The difference between the open location and those behind the berm were 11.6 and 9.9 dB for the 28- and 40-meter locations, respectively. The reductions obtained with the berm are compared to double edge diffraction theory and acoustic scale model results from the literature. The results of this study are reviewed in this paper and a comparison to FHWA Traffic Noise Model results is presented.

Study on Time-Space effect and earth berm of foundation pit

Excavation to the bottom of the pit after the expiry date, due to time-space effect, the shear strengths of soil are decrease, which produce safe hidden trouble. The mechanism of supporting structure and backfill of earth berm is analyzed in the paper. Combined with a commercial and residential complex foundation pit in Wuhan as the engineering background, according to the shear strength index of the soil after the foundation pit is retrieved from the foundation pit monitoring data after placing, the safety of the foundation pit is calculated. Calculated by finite element software, The stability coefficient of foundation pit decreases and the horizontal displacement exceeds the allowable value in the code if no action is taken after placing. After reasonable slope top width and slope ratio were adopted to backpressure backfill of the pit, the construction of residential property adjacent to commercial plot should continue until completion. The foundation pit monitoring data are normal during the time, which indicated that the bottom earth berm with back pressure can reduce the horizontal deformation and increased stability of the foundation pit, this method can provide some reference for similar foundation pit treatment.

Biomagnetic Monitoring vs. CFD Modeling: A Real Case Study of Near-Source Depositions of Traffic-Related Particulate Matter along a Motorway

A test site located along a 12-lane motorway east of Montpellier, France, is used to evaluate the potential of biomagnetic monitoring on traffic-related particulate matter (PM) to parametrize a computational fluid dynamics (CFD) simulation of the local airflow. Two configurations were established on the site with three vegetated flat-top earth berms of a basic design, and a fourth one was located windward to the traffic roofed with a 4-m-high precast concrete wall. As a first step, PM deposition simultaneously on plant leaves, on low-cost passive artificial filters, and on soils was estimated from proxies supplied by magnetic and X-ray fluorescence measurements on both sides of the motorway. These latter revealed that traffic-related pollutants are present on soils samples highlighted with a clear fingerprint of combustion residues, and wears of breaks, vehicles, and highway equipment. Maximum PM accumulations were detected in the lee of the berm–wall combination, while no significant deposition was observed on both sides of the flat-top earth berms. These results are in line with measurements from PM µ-sensors operated by the regional state-approved air quality agency. Finally, we compared the experimental measurements with the outcomes of a computational fluid dynamics (CFD) modeling based on the Reynolds-Averaged Navier–Stokes (RANS) equations that consider the traffic-induced momentum and turbulence. The CFD modeling matches the experimental results by predicting a recirculated flow in the near wake of the berm–wall combination that enhances the PM concentration, whereas the flat-top berm geometry does not alter the pollutants’ transport and indeed contributes to their atmospheric dispersion.

Stability of Extended Earth Berm for High Landfill

This study presents a stability analysis of an extended berm reinforced by geotextiles, with a steep slope of 1V:1.1H (vertical: horizontal). Finite element (FE) analyses were carried out to explore the failure mechanism and factor of safety (FOS) of the berm, on which the effect of the strength of geotextiles, leachate level, and anti-slide pile arrangement located at the toe of the berm were considered. It was found that: (1) failure surfaces developed along the interface between the new and the existing berms; (2) the FOS decreased as the leachate increased, and an FOS value of 1.42 could be obtained if the leachate level was controlled at a height of 20 m; (3) the tensile force of geotextiles was far lower than the available strength, which suggested that the geotextile had enough of a safety reserve; and (4) one row of longer piles at the toe of the berm performed better than two rows of shorter piles if the total length of piles was the same. The design and analysis of this project can be used as a reference for landfill expansion. Especially for a site condition with limited space, a geosynthetic-reinforced soil (GRS) berm is a safe, reliable and promising alternative.

Performances and Working Mechanisms of Inclined Retaining Structures for Deep Excavations

Because of the limits of struts, braceless retaining structures (BRS) have become a preferred option in deep excavation engineering. A type of BRS, that is, inclined retaining system, has been successfully applied in several projects. However, its performance and working mechanism have not been systematically studied. A case study and finite element results in this study show that inclined piles (IP) are more effective than vertical piles (VP), while composite inclined retaining structures (CIRSs) are more effective than IP in terms of deflection and bending moment reduction. The deformation‐control mechanism of IP mainly comes from the decrease in the active earth pressure. For CIRSs, the working mechanism is governed by several combined effects, that is, the rigid frame effect, inclined strut effect, earth berm effect, and gravity wall effect. For instance, in composite vertical and inward‐inclined piles (VIIP), inclined piles function as struts for the vertical piles in this rigid frame system and frictional force between the soil and the inclined piles significantly influences its retaining performance; the soil between the vertical and inclined piles plays a role similar to an earth berm; additionally, the entire retaining system is similar to a gravity retaining wall, which has relatively high overturning stability.

Urban park layout and exposure to traffic-derived air pollutants

Air quality in small urban parks improves rapidly with distance from surrounding streets. This arises because air pollutants disperse within parks where there are few sources. This was traditionally thought to arise from pollutant uptake by trees, but they can also reduce wind speed and potentially trap pollutants. It is increasingly evident that relatively little pollution is absorbed by trees over short distances typical of small urban parks. Nevertheless, trees and park infrastructure, also constrain the distribution of park users and thus lower their exposure. In this paper, we explore the exposure to traffic-derived air pollutants in the Hong Kong parks (Sha Tin and Sham Shui Po) and examine the way in which PM2.5 concentration and user distribution is affected by the spatial layout of park features. The modelled pollutant distribution was validated against measurements made in Sha Tin Park. Population-weighted exposure to traffic-derived pollution was quantified by overlapping pollutant and park user distribution. The results reveal how different design features (i.e. vegetation, earth berms and recreation areas) affect exposure during individual time period; most positively in Sha Tin Park where the design leads to a >50% reduction in exposure, early morning. In Sham Shui Po Park, exposure increases as park users are often attracted to facilities near a busy trunk road. This study reveals the heterogeneity of park user exposure to traffic-derived air pollution, which leads to uncertainty in health benefits provided by urban parks and suggests fine-scale exposure considered in thoughtful park design.

Can trees and forests help in improving environmental noise quality?

In this article, we focus on ground transportation noise abatement and more precisely road traffic noise control. From literature as well as our own experience in this field we aim at determining in which planting schemes are trees or forest strips beneficial to environmental noise abatement, for which expected noise attenuation and with which good practices.We start by a brief point on French regulation on road noise management and we present a synthetic review of main attenuation processes observed when sounds propagates through areas with trees: ground, diffusion and refraction effects. Then we consider some typical landscape configurations studied in the scientific literature and we provide with expected acoustic impact: a forest strip along a road infrastructure, a row of trees along a noise protection and trees in the city. We finally give a set of recommendations of correct use of trees and forest strips as an element to the improvement of outdoor sound environment. Our advice is to plant broadleaved evergreens or a mixture of broadleaved evergreens and coniferous, with a minimum density of 0.25 tree/m2. We also advise to cultivate the ground before trees planting and to use well-rotted organic matter. On the other hand we do not recommend planting trees at the top of earth berms.

Effectiveness of added roughness on berm surfaces

The reduction of traffic noise is often achieved using noise barriers or earth berms. More complex solutions have been reported making use of multiple diffraction effects (using complex or combined barriers) or roughened boundaries. Fractal-like surfaces will lead to increased absorption effects. The present paper focuses on the improvement of berms by adding different types of rugosity on its 3 sides. Using a BEM approach, several types of rugosity have been investigated either regular or irregular, simple or multi-level (fractal-like). Global efficiencies have been evaluated considering a realistic four-lane highway combining cars and lorries. In some cases, in a non-refracting atmosphere, a global reduction of 10 dB(A) relative to a smooth berm has been achieved. Effect of surface impedance, berm’s size and a comparison of 2D vs 2.5D computations are also considered.

Les arbres et les forêts peuvent-ils contribuer à l’amélioration de l’environnement sonore ?

In this article, we focus on ground transportation noise abatement and more precisely road traffic noise control. From literature as well as our own experience in this field we aim at determining in which planting schemes are trees or forest strips beneficial to environmental noise abatement, for which expected noise attenuation and with which good practices.We start by a brief point on French regulation on road noise management and we present a synthetic review of main attenuation processes observed when sounds propagates through areas with trees: ground, diffusion and refraction effects. Then we consider some typical landscape configurations studied in the scientific literature and we provide with expected acoustic impact: a forest strip along a road infrastructure, a row of trees along a noise protection and trees in the city. We finally give a set of recommendations of correct use of trees and forest strips as an element to the improvement of outdoor sound environment. Our advice is to plant broadleaved evergreens or a mixture of broadleaved evergreens and coniferous, with a minimum density of 0.25 tree/m2. We also advise to cultivate the ground before trees planting and to use well-rotted organic matter. On the other hand we do not recommend planting trees at the top of earth berms.

Berm design to reduce risks of catastrophic slope failures at solid waste disposal sites.

Existing waste disposal sites are being strained by exceeding their volumetric capacities because of exponentially increasing rates of municipal solid waste generation worldwide, especially in densely populated metropolises. Over the past 40 years, six well-documented and analyzed disposal sites experienced catastrophic failure. This research presents a novel analysis and design method for implementation of a series of in-situ earth berms to slow down the movement of waste material flow following a catastrophic failure. This is the first study of its kind that employs a dynamic landslide analysis model, DAN-W, and the Voellmy rheological model to approximate solid waste avalanche flow. A variety of single and multiple berm configuration scenarios were developed and tested to find an optimum configuration of the various earth berm geometries and number of berms to achieve desired energy dissipation and reduction in total waste material runout length. The case study application of the novel mitigation measure shows that by constructing a series of six relatively inexpensive 3 m high earth berms at an optimum distance of 250 m from the slope toe, the total runout length of 1000 m and associated fatalities of the Leuwigajah dumpsite catastrophic failure in Bandung, Indonesia, could have been reduced by half.

The effect of rehabilitation measures on ecological infrastructure in response to acid mine drainage from coal mining

Water treatment is an important ecosystem service in natural systems and wetlands are well-known to have increased functionality in this regard. The rehabilitation of productive wetlands plays an important role in improving this functionality in degraded wetlands, but it is not well-known to what extent these activities improve acid mine drainage impacted waters. The aim of this study was to evaluate the significance of the effect of such interventions on the ecological functioning of a test wetland affected by acid mine drainage. A degraded wetland influenced by acid mine drainage in the Mpumalanga Province of South Africa was identified for the case study. This site was rehabilitated using a variety of hard (e.g., weirs/dams) and soft (e.g., earth berms) structures and examined to determine whether its ecological functioning (i.e., the improvement of water quality) and biotic community structures have improved. From the results it was evident that a substantial improvement in water quality occurred below the rehabilitated area, even though the wetland still continued to receive acid mine drainage. This was observed through the decrease in metal pollution in conjunction with an increase in pH and alkalinity levels. This resulted in increased productivity, reduced toxicity (embryotoxicity and teratogenicity), as well as changes in the biotic community structures which were a reflection of a less polluted environment. The study has shown that the rehabilitation of ecological infrastructure can be used to mitigate the effect of coal mining related pollution such as acid mine drainage. In the face of ever increasing land use activities that occur globally to meet the demands of growing populations, this information can be useful to mitigate negative residual influences resulting from these activities, e.g. acid mine drainage.

Upper bound seismic rotational stability analysis of gravity retaining walls considering embedment depth

Stability analysis of gravity retaining wall was currently based on the assumption that the wall had no embedment depth. The effect of earth berm was usually neglected. The present work highlighted the importance of embedment depth when assessing the seismic stability of gravity retaining walls with the pattern of pure rotation. In the framework of upper bound theorem of limit analysis, pseudo-static method was applied into two groups of parallel rigid soil slices methods in order to account for the effect of embedment depth on evaluating the critical acceleration of wall-soil system. The present analytical solution is identical to the results obtained from using limit equilibrium method, and the two methods are based on different theory backgrounds. Parameter analysis indicates that the critical acceleration increases slowly when the ratio of the embedment depth to the total height of the wall is from 0 to 0.15 and increases drastically when the ratio exceeds 0.15.

Philip Johnson's Painting Gallery: Case study of a modernist earth berm roof replacement and restoration

Philip Johnson's Painting Gallery is a National Historic Landmark earth berm building built in 1965 at the Glass House in New Canaan, Connecticut. The gallery design is based on an ancient Greek tomb also known as the Treasury of Atreus, and contains an exceptional collection of modern art including works by Andy Warhol, Frank Stella and Robert Rauschenberg. After the National Trust for Historic Preservation became the stewards of the Glass House site in 2006, recurring leaks at various locations became increasingly problematic at the Painting Gallery. It was determined that a comprehensive approach was needed to address the water emanating from under the berm at the roof and rising walls for the conservation of the building itself and to protect the building's highly significant art collection. The comprehensive approach began with a six-month study and evaluation of the building including review of all archival materials, trench probes, consultations with technical product representatives and proposed waterproofing and roofing system mock-ups.The study determined the repair scope of work that included replacing the original 1965 roof membrane with a cold-applied Kemper roofing system at the main roof and sub-grade roofs under the berm. To access the roof work areas, all of the 54 Redstone copings, each weighing 1200-1500 pounds, were removed by a crane and over 200 cubic yards of the earth berm were removed by hand. The scope of work also included restoration of the full profile and landscaping of the earth berm over the building in keeping with Johnson's original design intent.Construction began in July 2013 and was complete in October 2013. Mary Kay Judy was the Principal Architectural Conservator, Robert Silman Engineers were the consulting structural engineers for mobilisation and Nicholson and Galloway was the General Contractor.

Analysis of Earth Berm on the Impact of Cantilever Retaining Structure Based on ABAQUS

Software ABAQUS was carried out to analyze the effect of earth berms on behavior of cantilever retaining structure, and the soil was in modified Cambridge model. The results showed that: in the premise of ensuring the stability of earth berm itself, height and width of earth berm increased reasonably can reduce the horizontal displacement and bending moment of supporting structure, so as to improve the safety of the supporting structure, and save the cost of project.

Application of Earth Berm in Foundation Pit Engineering

Referring to a project in Tianjin, the paper has described the mechanism of the earth berm, and analyzed the influence on supporting structure from the earth berm using finite element. It was observed that the wider of the earth berm with constant height the smaller of the supporting structure deformation, and the deformation will tend to be stable when width reaches specific value. With constant width, the higher of the earth berm the smaller of the supporting structure deformation. The retaining of the earth berm should be reasonable and safe. Under the premise of the slope stability, the paper suggests that the height of the earth berm should be 2/3 of the excavation depth, and the width should be 1/2 of the excavation depth.

Earthship monitoring and thermal simulation

This paper describes the research which investigates the thermal performance of Earthship, an autonomous, earth-sheltered housing concept that claims to require no active heating or cooling systems despite extreme climatic conditions. This research aims to test these claims through monitoring and thermal simulations. The study involves monitoring the indoor conditions in an Earthship home in New Mexico, USA and uses the measured data to calibrate a computer model used to simulate the thermal performance of the home for further analyses. The second part of the study compares Earthship thermal performance located in a temperate climate in Australia with that of buildings incorporating different wall construction materials such as strawbale, rammed earth, and brick veneer. Results from both these studies substantiate the claims. The effect of including a greenhouse, earth berm, and internal wall material is also explored and quantified. The paper concludes with a discussion of the scope for reducing home energy use through the use of Earthship design principles and construction methods and the viability for building these houses in the Australian suburbs.