Earth Fill Research Articles

Experiments on suffusion of coarse soils from an ageing British dam

This study presents a laboratory investigation on the susceptibility of suffusion in soil samples collected from a very old earth dam. The dam, rebuilt around 1800, is composed of two earth fills and lacks a clay core or filtration components, making it vulnerable to internal erosion. Following an inspection in 2006, concerns were raised about the dam’s vulnerability to internal erosion during strong floods. Boreholes and vibro-cores were performed to collect samples, which were then tested for suffusion susceptibility. The study found that four out of six samples were highly susceptible to suffusion erosion, with the erosion process starting at gradients much lower than unity. The opposite was observed for samples with fines content greater than 30% and showing some plasticity. The results were compared to predictions from seven geometric criteria found in the literature, but none of the methods could forecast the behaviour of all tests. The study highlights the need for laboratory tests when there is no agreement between the predictions from available criteria. The findings of this study were used to inform the rehabilitation of the dam, which included installing sand filters designed to capture the smallest particles and relief wells distributed along the entire length and height of the eastern embankment. The study demonstrates the importance of assessing suffusion susceptibility in embankment dam safety control and the need for laboratory tests to validate predictions from geometric criteria.

South Atlantic Anomaly Evolution Seen by the Proton Flux

AbstractThe SEM‐2 (Space Environment Monitor‐2) instrument embedded on the NOAA‐15 Low Earth Orbit satellite provides measurements of trapped protons in the Van Allen inner belt from 1998 to nowadays. This continuous set of measurements enables us to study the dynamics of the South Atlantic Anomaly (SAA) over more than two solar cycles, particularly, its temporal evolution. We observe that the area of the SAA is anti‐correlated with the solar activity. Two physical processes explain this anticorrelation. First, the more the Sun is active the more it disables the cosmic rays to reach the Earth's magnetosphere and fill in the inner radiation belt with protons. Then, when the Sun is more active, the upper atmosphere is warmer and therefore absorbs more protons from the radiation belt. Then, we investigate the protons flux centroid of the SAA. The temporal evolution of its position, latitude and, longitude is studied over the same time interval (1998–2022). We notice that the latitude of the centroid is also anti‐correlated with the solar activity whereas the longitude seems absolutely independent. The temporal evolution of the position of the centroid shows a drift of the SAA. Indeed from 1998 to 2022 the SAA drifted of about 7° West. The SEM‐2 instrument measures flux for protons of different energies (16, 36, 70, and, 140 MeV). For each energy, the SAA dynamic has a similar trend but with different values. These differences are investigated and the results are discussed.

Ground Tire Rubber as a Sustainable Additive: Transforming Desert Sand Behavior

Managing waste tires presents a significant challenge globally, particularly in regions experiencing high temperatures and shortage of landfill sites. This issue is affecting countries like Kuwait, where the abundance of waste tires is a major source of environmental and safety risks, particularly during the intensely hot summer months. This extreme heat has sparked numerous fires, leading to substantial air pollution due to thick black smoke. Given the limited disposal options, recycling waste tires and finding practical applications for ground tire rubber (GTR) is essential. To address the challenge, a comprehensive laboratory testing program was conducted, using locally produced rubber aggregates as an additive to Kuwait's local surface sands. Two new variables were examined namely the size and gradation of the GTR, and the density of the compacted mixes. For this purpose, two different sizes of rubber aggregates, fine and coarse produced locally, were utilized, and the impact of relative compaction on the strength and compressibility of the mixtures was investigated by testing samples compacted to the maximum density and to 95% of the maximum density. The results suggest that combining local surface sands with rubber tire additives results in a lighter, more permeable, and compressible material, contributing significantly to sustainable waste management. With 20% rubber additive the maximum dry density decreased by nearly 20%, and the permeability increased by 1.74–3.11 times and the compression index increased by 6.15 and 3.8 times with fine and coarse rubber respectively. The angle of friction remained unchanged at 36° with the addition of coarse rubber and decreased by 3°–4° with fine rubber. The change in behavior although not an increase in the strength and stiffness, offers a range of suitable practical applications in civil engineering and environmental management, including use as a drainage layer, embankment construction on soft ground, earth fill around retaining walls, an additive in asphalt mixes, and in manufacturing compressible tiles for sports facilities.

Piping Stabilization of Clay Soil Using Lime

Construction of earth fill dams offers a cost-effective solution for various purposes. However, their susceptibility to internal soil erosion, known as piping, poses a significant risk of structural failure and resultant loss of life and property. Soil stabilization emerges as a practical technique to fortify these dams against such threats. This study investigated the impact of lime on the internal erosion properties of clay soils, focusing on CH and ML soil types. Specimens of different lime content were prepared and remolded at 95% relative compaction and optimum moisture content. Hole Erosion tests at varying lime concentrations and curing durations were adapted to conduct the investigation. This investigation aims to optimize lime content and curing time for cohesive soil stabilization against internal erosion. Findings revealed that 2% and 5% of quicklime, by dry weight of the soil, effectively stabilized CH and ML soils, respectively, against internal erosion, with a two-day curing period proving optimal. Furthermore, the addition of lime significantly enhanced erosion rate index and critical shear strength in clay soil, underscoring its efficacy in soil stabilization efforts.

Seismic Assessment of Clayey-Core Earth Fill Dams Using Performance-Based Fragility Curves and Finite Difference Analyses

Seismic Assessment of Clayey-Core Earth Fill Dams Using Performance-Based Fragility Curves and Finite Difference Analyses

Analisa Perbandingan Penurunan Awal Bendungan Tipe Material Timbunan Urugan Batu dan Urugan Tanah (Studi Kasus Bendungan Digoel-Papua)

To create prosperity for the people of Papua Province. The government has made one of the programs, namely the construction of the Digoel Dam in Boven Digoel Regency – Papua. The successful construction and operation of a dam requires a comprehensive evaluation of the design prior to commencement of the construction process. This study aims to analyze the initial settlement that occurred in the Digoel dam type earth fill and rock fill. Initial settlement analysis was carried out using the modulus parameter obtained from the literature. SIGMA/W software has been used to estimate dam crest settlement due to static loading. From the results of the analysis of the initial settlement of the dam with the rock fill and earth fill types, it is accepted that the maximum permissible settlement is 1.59%.

Hydraulic Dam Safety Evaluation of Gateless Bottom Outlet and Spillway in Dry-Dam for Flood Control

Purpose: This study intends to carry out the assessment of an earth fill dry dam safety for flood control from the perspective of hydraulic points of view. Theoretical reference: Ciawi dry dam is the first dry dam built in Indonesia and has been operated since end of year 2022. The dam intends to reduce Q50 flood in Ciliwung River, it is design to reduce the peak flood and extend the peak of flood in Jakarta. Method: The methodology consists of by carrying out the experiment in hydraulic laboratory test by 1:50 scale; then using the software of FLOW-3D for analyzing the numerical modeling. Some design discharge was evaluated and researched for the scenarios as follow: 2(two) gate openings, 1 gate opening and 1 gate close. Result and Conclusion: The result shows that there is a good method between theoretical formula, numerical simulation and physical modeling. Implication of research: The location of spillway is separated from bottom outlets, it is placed at left side of abutment, it is an ogee type side spillway while the bottom outlets located in the right side of abutment with two conduits which to allow the inspection or maintenance during the operation is mainly designed at original bed level and to be able to pass through the sediments inflow naturally during the flooding periods. Both structures are designed to meet the dam safety in the perspective of the hydraulic issue. Originality/ value: The comparison between laboratory test and the Flow-3D software is done by a scenario with one gate opening and one gated close by using the PMF discharge to confirm the satisfactory of dry dam outlet capacity.

The impact of assumptions on deterministic and probabilistic analyses of earth fill embankments

This paper considers the impact of assumptions made when formulating analytic approaches to deterministic and probabilistic analyses of slope stability. The assumptions reviewed were presented in a paper, Waddell (2023) that presented semi-quantitative stability assessment using survey data, deterministic and probabilistic slope stability analyses of fill embankments constructed from residual soil and weathered bedrock in Western Sydney. A single variable fill strength was adopted, that was obtained from an Infinite Slope analysis assuming fully saturated fill. Rainfall records were used to predict risk of saturation to calculate annual probability of slope failure. The impacts of assumptions used to calculate the strength parameter, factor of safety and predicted failure probability are addressed in this paper. Saturation assumptions, the choice of limit equilibrium model, shape of the probability distribution functions, and spatial correlation of material properties are considered.

Suffusion in densely compacted Satozuka pumice sand and its impact on static loading undrained shear strength and dilation behaviour

Pumice sand of volcanic origin contains a high fraction of non-plastic fines (>40 % for Satozuka pumice sand in Sapporo, Japan). Suffusion in such soil can wash away a portion of the fine particles and alter the soil microstructure. The moisture content and degree of compaction can affect the suffusion characteristics of soil deposits, however their effect has not yet been evaluated. Future construction sites in growing Sapporo City, consisting of pumice sand, will require a high degree of compaction (over 90 % and preferably over 95 %) as this sand is prone to suffusion in spite of its dense state. The aim of this study is to assess the impact of suffusion on densely compacted pumice sand with a high proportion of fines, based on its mechanical properties, with an emphasis on shear strength and dilatancy. Firstly, the suffusion characteristics of Satozuka pumice sand were evaluated. Subsequently, undrained triaxial tests (CU¯ tests) under monotonic loading were conducted on high-density specimens, with suffusion and without suffusion, to study the impact of suffusion. It is seen in the results that the hydraulic conductivity, shear strength, stress paths, and dilatancy are all noticeably affected by suffusion. The specimens with suffusion exhibit an increase in residual shear strength and maximum deviator stress under shearing and experience an earlier occurrence of phase transformation from contraction to dilation during shearing. This tendency implies that suffusion has no significant negative impact on the deterioration of earth fill made from pumice sand and non-plastic fines, and that it persists at degrees of compaction between 80 % and 100 %.

Assessment of Foundation Rocks of the Proposed Makhol Dam in the Northern Salah- Alddin, Iraq

This study was done as an assessment of the foundation rocks of the proposed Makhol dam in the northern Salah- Aiddin Governorate, Iraq. This study consists of field, laboratory, and office work. It was noticed in the field that the thirteen (13) different rock mass units comprised along the dam axis. Three rock mass classification systems were adopted (used) in the evaluation: Rock Mass Rating, Dam Mass Rating, and Geological Strength Index. The DMRSTA (RMR related to dam stability) values for the right bank range between 36.97- 73.8. These values indicate good stability of foundation rocks of the right part with the presence of some instability of primary effect (not serious effect) in unit no.3 (Fatha Formation), and the DMRSTA values of the left bank range between 44.97– 61.7 These values indicate no instability for the foundation rocks on the left bank for all rock mass units. The RMRBD89 values range between 37– 73.3. These values reveal that the foundation rocks are desirable and can be excavated for rockfill and earth fill dams, but for the gravity dam, the rock mass unit 3, must be excavated to the desirable RMRBD89 value in the case of a gravity dam, and indicate that the foundation rocks do not require grouting when the type of dam is earth fill. Some rock mass units require grouting (spot grouting), especially for the rock mass unit 3 when the type of dam is Rockfill, and require systematic grouting, especially when the type of dam is Gravity. The Roc Lab software was used for the purpose of determining the mechanical properties of all rock units through the Hook-Brown failure criterion.

Evaluation of Carbonate and Heterogenous Rock Masses for the Dam Foundation: A Case Study at Kanarwe River Basin, Sulaimaniyah, NE Iraq

Evaluating rock masses for dam foundations, especially heterogeneous rock (flysch), becomes imperative and requires accurate geomechanical classifications. The rocks at the Kanarwe river basin, especially at a proposed dam site (Goma-Qazan near Khewata, Sura Qalat villages), mainly consist of interlaying massive carbonate rocks of the Aqra Formation with flysch rocks of Tanjero Formation. Therefore, selecting appropriate dam types is challenging and very risky. This study conducted a detailed study of lithology, discontinuity condition, rock sampling and laboratory tests to determine the site suitable for dam construction using the quantitative GSI, Rock Mass Rating, and Dam Mass Rating geomechanical classification systems. A new procedure was suggested for calculating stress relaxation and damage level (disturbance factor D) in rock masses. The Dam mass rating related to the foundation stability shows a good stability indication ranging from 43.7–82.9, indicating foundation suitability for all dam types. The foundation excavation desirability and consolidation grouting were evaluated based on dry basic rock mass rating, which shows that the site is suitable for earth fill and hardfill dams. However, the rock mass units require spot and systematic grouting for gravity and Arch dams, respectively. Ec/Em (deformation modulus of the dam/deformation modulus of foundation rocks) values for massive carbonate rock range from 0.18–0.93; they indicate site suitability for arch, gravity dam, earth fill and hardfill dams. While the Ec/Em values for flysch rock mass units range from 1–6.4, they indicate some units have a serious problem situation and need treatment based on the types of dams.

Seepage Simulation of the Proposed Makhool Dam in North Iraq

This study aims to simulate water seepage and identify areas of weakness in the foundations through the right and left sides of the proposed Makhool dam in northern Iraq, using the finite element method by advanced computer software (SEEP/ W, 2012). The earth fill dam is 3670 m long on the Tigris River. Many attempts were made to ascertain the program results on the supposed earth dam and compare the results with those of other analytical methods to verify the program. The results are comparable, showing that the program is suitable for use in the seepage analysis at the proposed Makhool dam. According to the seepage analysis, the quantity of seepage through the left side of Makhool is acceptable within permissible limits; however, the right side has a lot more than the left side because of the presence of cracks, fractures, and cavitations in the stratigraphic sequence of Fatha formation at great depths in the gypsum beds under the diaphragm. The results indicate the need to lower the diaphragm about 6 m extra in the foundation's zone to a level of 49 m.a.s.l until reaching the low permeability clay bed within the foundations' zone. This action will reduce the amount of seepage and flow velocity and avoid using more grouting during the dam life. The design limits of the piezometric head (total head) were also determined, which are supposed to be read by the monitoring devices when operating the dam at the maximum level of the reservoir and the normal operating levels.

Transforming waste into sustainable solution: Physicochemical and geotechnical evaluation of cement stabilized municipal solid waste incinerator bottom ash for geoenvironmental applications

The present study investigates the potential of Municipal Solid Waste Incinerator Bottom Ash (MSWI-BA) collected from a waste-to-energy conversion plant in Delhi for geoenvironmental applications. The physicochemical and geotechnical properties of freshly quenched MSWI-BA were examined for cement-stabilized specimens with varying cement content ranging from 3% to 9%. The study aimed to assess the influence of pH and metal(loid)s concentrations during the standard curing period. The results demonstrated that adding cement formed C-S-H and C-A-H gel and Ca-hydrates within the matrix of 28-day cured samples. Specimens with 7% and 9% cement content exhibited the presence of quartz, calcite, belite, and other strength-enhancing compounds, leading to significant improvements in unconfined compressive strength and California bearing ratio values by up to 119.37% and 96.42%, respectively. Thermogravimetric analysis indicated moisture loss and breakdown of aluminates and silicates caused cracking at temperatures above 720 °C. The incorporation of cement resulted in the encapsulation of heavy metals, with the concentrations of Zn and Cu remaining within permissible limits. This study confirms the applicability of cement-stabilized MSWI-BA for flexible road pavements, earth fills, and various geoenvironmental applications.

Stability of earth fill embankments constructed from residual soils including impacts of climate change

The paper looks at the stability of fill embankments using data from failed embankments constructed from residual soils in Western Sydney. Semi-quantitative, deterministic and probabilistic methods are used to consider the stability of such fill embankments. A simple, infinite slope model was adopted to carry out deterministic and probabilistic analyses. Climate data was used to assess the likelihood of fill saturation and the impacts of climate change on predictions.

Saltwater intrusion management at different coastal aquifers bed slopes considering sea level rise and reduction in fresh groundwater storage

Coastal fresh groundwater management is a challenging research topic due to the relevance of these resources and the huge suffered risks due to global change and overpopulation. The geometrical features of coastal aquifers play a control role in saltwater intrusion (SWI). Seawater level rise and the reduction in aquifer fresh groundwater storage are promoting SWI. All these key factors are considered with two different numerical approaches defining schematic management criteria bottom using the numerical code SEAWAT. The former approach adopts the well-known Henry’s problem; the latter is based on the real study case of the Gaza aquifer (Palestine). Different aquifer bed slopes (ABS), and hydraulic and physical methods for SWI management are considered together with SLR, recharge reduction, and over pumping. The results showed that the land side ABS cases show more SWI than sea side and horizontal ABS. Cut-off walls and check dams are effective to manage SWI in horizontal ABS more than in other slopes, also the subsurface dams, earth fill and recharge of freshwater are good methods in land side ABS while the abstraction of brackish water and combination of recharge with abstraction are better to mitigate of SWI in sea side ABS. Useful comparing tables and considerations are defined with the purpose to guide the preliminary selections of new management solutions for reducing the effect of the global change on groundwater resources for different slopes aquifers around the coastal world.Graphical abstract

Suitability of Injana Clays for filling Materials

The study aims to evaluate suitability of injana formation clays for filling material in Sharqad area / North of Iraq, The exposed rocks are Fat’ha & Injana Formations in addition to Quaternary deposits. Three stations are studied in southern west limb of Khanuqa anticline near the north western plunge of this anticline, Geotechnical properties show that the type of soil are low plasticity (CL)and low plasticity silt(ML).The specific gravity values ranges between (2.65-2.72), the chemical analysis show that the ratio of total dissolved salts ranges between (3.9-5.2)% ,while the ratio of gypsum content ranges(2.7-3.0)%, pH values ranges between (7.8-8.0).In last the most geotechnical properties of Injana clays are accepted as filling materials for earth fill dams when compare with Iraq specification (Sorb/rs) except the ratio of (TDS) for stations,1&3.

Suitability of Quaternary Deposits in Alam Area as Filing Materials in Earth Fills Dams

The Study aims to evaluate the suitability of quaternary deposits in AL-Alam area as filling materials in earth fill dams. The geotechnical properties of deposits for three stations show that the type of soil is (ML) and the curves of grain size analyses confirm the curve of Zone C., while the ratio of total dissolved salts(TDS) and gypsum contents ranges between (2.71-8.61)% and (0.18-0.68)% respectively The values of liquid limit and plastic limit ranges between (40.2-44.7)% and (10.5-13.7)% respectively. According to Iraqi specification, the deposits of station (3) are suitable for filling materials in earth dams, while the geotechnical properties of the deposits in the stations (1) and(2) are within the specifications ranges except the ratios of (TDS).

Evaluation of water resources: A case study of Rohtak district, Haryana

Water is one of the most important natural resources for life. Because of the rapid increase in population, urbanization, and industrialization, the demand for water to meet various needs is constantly increasing. Water that is present below the Earth's surface and fills any gaps in the soil or geologic strata is known as groundwater. It is additionally known as subsurface water. Data related to underground water table were obtained from Central Ground Water Board of the Ministry of Water Resources. Maps of underground water table depth, quality and surface water resources were prepared in Arc GIS software. After the analysis of maps, the depth of the underground water table in the study area ranges from 0 to 20 meters. The maximum area of the study area is 3-10 meters, which covers 48.35% of the study area. The minimum area is 10-20 meters deep and covers 1.43% of the study area. In Rohtak block, the maximum depth is observed in the villages of Brahmanvas, Chamaria, Aryanagar, and Bohar. The quality of groundwater varies from fresh to saline. Fresh underground water quality occupies the largest area, accounting for 59.8% of the study area. Saline underground water quality accounts for 0.5% of the study area. In terms of surface water resources, this district lacks a perennial river. The main irrigation channels in this area are artificial drain no. 8 and sub drains, major canals, distributaries, and minor canals. This research paper will make a better understanding of water resources in Rohtak district. It will help to analyse and understand the current status of underground water depth, quality and surface water to build up any water resource management plan. A water resource management plan will ensure the sustainable use of water resources which is very important for our ecosystem.

Comparative evaluation of the environmental impacts of geosynthetic Mechanically Stabilized Earth walls

Integrating sustainable approaches in all the engineering fields became mandatory for better life and future. This article explains the comparative advantages of Geosynthetic Mechanically Stabilized Earth (MSE) walls over four other conventional types (Plain Concrete Gravity walls; Reinforced Concrete Cantilever walls; Masonry Brick walls; and Gabion Limestone Cage walls) from a sustainability perspective over various heights. The study comprises a detailed life cycle assessment (LCA) following the ISO 14040 and 14044 frameworks. The results revealed that constructing MSE walls rather than the other conventional walls contributes to 10 of the 17 United Nations (UN) Sustainable Development Goals (SDGs). GaBi's software and embedded database were utilized for the first time in such an assessment. The article demonstrated that the construction of gravity walls requires large amounts of cement/concrete, which emit a significant amount of geogenic CO2. In contrast, the construction of MSE walls requires considerably less concrete and more backfill. The construction of cantilever walls requires less concrete than gravity, yet more than MSE walls for their construction. The structure of masonry walls was found to have less impact on the environment than the construction of comparable gravity and cantilever walls. The benefits of MSE walls over conventional walls increased with increasing wall height. The significant benefit comes from using soil backfill as the chief structural component rather than concrete. This article is deemed an essential step in achieving circularity and circular economy regarding sustainable earth fill retaining structures.

Evaluation of Seepage on the Right Side of Haditha Dam, West of Iraq

The study aims to assess the water seepage through the right side of Haditha dam structures in western Iraq, using the finite elements method by an advanced computer software (SEEP/ W, 2012), the earth fill dam is 9 km long on the Euphrates River. Many attempts were done to ascertain the results of the program on a supposed earth dam and compare the results with the other analytical methods. The comparison reveal to very close results, and this indicate the suitability of the software for Haditha dam structures seepage analysis. After the verification of the results, then the real design information of the dam was input to analyse the dam, the input data are the height of the dam, width, slope of upstream and downstream, dimensions of the core, hydraulic conductivity of the different materials of the dam and the foundations. The results obtained from the SEEP/W2012 software were compared with the actual field data of the seepage amount for years (1989 - 2017) and with the water level in the dam reservoir for different periods. The result of comparison gave an idea to the efficiency of the dam protection against the seepage.Through the SEEP/ W data, which simulates the dam sections, levels and discharges that calculated by the software, which is compatible with the field monitoring data, it can be said that the software was able to simulate the actual conditions of the dam and identify the weakness zones. Where the results displayed that the asphaltic diaphragm in good condition and efficient on the right side of the dam. The grouting curtain in the right side is efficient, except for the area between the two stations 15 and 25, the zone between two stations need a continuous monitoring. The results also reflect that earth fill materials and the central core of the dam are efficient, and seepage within permissible design values.