GeoStudio Software Research Articles

The effect of changes in sealing wall and horizontal drainage of Golfaraj dam on the values of lifting pressure parameters and maximum outlet gradient

Dams are always considered as infrastructure structures and have vital value. An earthen dam is a body consisting of discontinuous soil particles of various sizes that need to be placed in front of a stream of water to store it. As water is stored behind the dam and its surface area increases, the potential energy of the water particles increases and due to its porous nature, it begins to move in it. Today, the main problem that has attracted the attention of engineers is the issue of seepage. So that the presence of seepage in earthen dams is inevitable. The aim of the present study was to investigate the different positions of the sealing wall and to select the best angle, length, number and distance, as well as to select the appropriate length for horizontal drainage Due to the geotechnical conditions, it is against the phenomenon of rug and lifting force. GeoStudio software is a collection of soil mechanics software based on finite element method through which various modellings and analyzes can be examined. This software includes various models such as SEEP / W which is used for flow analysis and seepage. In the present study, the SEEP / W model of this software package has been used. The SEEP / W model is based on the Darcy relation, which expresses the passage of water flow through the soil in both saturated and unsaturated states. The results showed that for the sealing wall located above the core, an angle of 20 degrees and for the sealing wall located downstream of the core, an angle of 100 degrees are suitable. Also, the optimal length of the sealing wall is 24 meters and its optimal number is 2. Increasing the distance between the two vertical sealing walls has increased the lifting pressure and reduced the maximum outlet gradient. Increasing the horizontal drainage length reduced the maximum output gradient, while having little effect on the uplift pressure.

Study on Rule of Heavy Metal Cu2+ in Small and Medium-Sized Tailings Ponds under Rainfall-Evaporation-Transpiration Coupling

In order to research the heavy metal migration rule of small and medium-sized tailings ponds under the action of climate, vegetation and groundwater, this paper consider the rainfall-evaporation-transpiration and coupling effect of groundwater, establish the model of different dam height, slope ratio, permeability coefficient and migration time impact on the migration of heavy metals of tailings dam, applied to Geostudio software, based on the orthogonal design method of factors significant difference analysis and design method of the comprehensive factors analysis, make up the simulation of the tailings heavy metal pollutants concentration of Cu2+ migration law. The results show that the height of tailing dam is inversely proportional to the average migration velocity of pollutant Cu2+. The effect of slope ratio on migration concentration of Cu2+ pollutant in tailings pond is not significant. The permeability coefficient has a highly significant influence on the migration of heavy metal Cu2+. At the same depth of tailings pond, when Cu2+ migrated for 365 days, the permeability coefficient increased with the increase of pollutant Cu2+ concentration. The concentration of heavy metal increased with the increase of migration time.

Stability Assessment of Zoned Earth Dam under Water Particles Fluidity Effect: Hemren Dam as Case Study

Recently the numerical modeling using finite element method is take into account as a very effective tool to investigate the desired behavior of structures in geotechnical engineering. Earth dams are a water retention structures that are normally wide constructed around the world due to its significant features. These structures may be failed due to exposure to an earthquake and this will result in disaster. The main objective of this study is to assess the slope stability and the seismic response of an earthen dam. Since the matter of seismic response is still have a considerable lack of information for earth dams as a unique structure. Hemren zoned earth dam that is located in Diyala governorate, northeast of Iraq that considered as an active seismic zone has been considered as case study. Numerical modeling has been done in this study using Geo studio software. Factor of safety was calculated with different water levels in order to evaluate the dam safety with different operation water level. The excited earthquake is Elcentro while three values of peak ground acceleration were used which are 0.2, 0.25 and 0.3 g and the duration time is scaled to 10 seconds. In addition, three key points (at the core, the shell and the foundation) that represent the dam construction material are used to evaluate the dynamic response within the dam body. The results revealed that the factor of safety is increased when the water level is increase, but in the increasing in the magnitude of factor of safety with water depths of (10 and 15) m was more than the other depth. The zone of the dam core shows a negative pore water pressure value. That leads to an increasing in effective stress at the core of the dam.

A methodology for transport modelling of a contaminated site with perfluorooctane sulfonate due to climate interaction

In this study, a numerical model was developed to predict perfluorooctane sulfonate (PFOS) migration in a contaminated site due to precipitation and evapotranspiration over 100 years. The soil physicochemical properties including sorption isotherm characteristics were used to model PFOS transport (advection and dispersion), and attenuation (adsorption and decay) processes using the GeoStudio software. The model was calibrated using the results of a leachate test on a reconstituted contaminated soil specimen. The simulation of the contaminated site showed that in the current situation where the site is covered by a concrete slab, PFOS remains at the site beneath the concrete slab for a long time with decay being the dominant factor contributing to its reduction over time. It took several decades for PFOS to contaminate groundwater. The PFOS level in groundwater reached the threshold value for drinking water in 25 years and continued to increase in the long term, extending horizontally to an area up to five times the size of the contaminated site. This issue needs to be considered when digging boreholes for drinking water close to the contaminated site.

Optimizing the liners thickness to design a landfill

Abstract Management of solid waste and leachate migration is a challenging task all over the world. Leachate was a fluid material produced during decomposition process contains heavy metals, high concentrations of organic compounds etc., contaminates soil and groundwater. Landfills are designed and constructed with liners to avoid the heavy metals transverse into the ground. Liner is a compacted layer of clay and Geosynthetic materials of various designed thicknesses preferred to the specified landfills. Present study is on the design of various liners with varying thicknesses for a landfill using numeric model using CTRAN/W clone in Geostudio software. Clay and Geosynthetics materials are used as liners and bore wells are provided at different radial distances with varying depths from landfill. Lead (Pb) and Cadmium (Cd) are assigned as contaminants on the liners. From the results, it has been observed that concentrations of Pb and Cd are decreasing with increase in liners thicknesses for both compacted clay liner (CCL) and Geosynthetic material liner. Duration of Pb and Cd concentrations to reach the bore wells is also increases. The specified liner thickness is analyzed after the comparison of concentration at end of liners, with and without using Geosynthetics to design a landfill. Time of concentration of Cadmium (Cd) is greater than Lead (Pb).

Numerical simulation of slope stability of the abandoned dreg site

A mathematical model of No. 1 abandoned dreg site of the newly-built highway from Xiangle village, Pingyao County to Hougou village, Qinyuan County was developed using GeoStudio software. The stability of the abandoned dreg site was simulated and analyzed under rainstorm. As a result, the influence of rainfall infiltration on slope seepage field is not limited to the rainfall process. The slope stability coefficient decreases significantly during the rainfall and the decreases slightly after the rainfall stopped due to continuous rainwater seepage. The minimum safety coefficient is 2.292 at 24h, greater than the allowable value, which demonstrates that the slope is stable.

Formation mechanism and stability analysis of the DR landslide in national road 534 of Datian, Sanming, Fujian Province, China

Rainfall-induced landslides occur frequently along roads in Fujian Province, China. Previously, landslides located at roads in Jianou and Yanping in Fujian were reported to claim 23 and 24 lives, respectively. The DR landslide (located on National Road 534 of DR village, Datian County, Sanming City, Fujian Province), with a state of instability and the potential of burying the road and buildings and causing human casualties, is representative. Therefore, there is a need to analyze the stability of the DR landslide. Through detailed reconnaissance and modelling, this study investigated the characteristics, formation mechanism and stability of the DR landslide. Based on GeoStudio software, the stabilities of the upper, middle and lower parts of the landslide were explored in natural, rainfall, earthquake and coupled rainfall-earthquake conditions, with the finite element, Bishop’s simplified methods and others. The results demonstrate that under the above four conditions, the upper and middle parts were stable with stability coefficients greater than the standard engineering values for China, while the lower part was unstable with stability coefficients of critical slip surfaces of 0.871, 0.798, 0.867 and 0.727, respectively, which are less than the standard values. Compared with the natural condition, rainfall influenced stability less, whereas the earthquake and coupled conditions greatly affected the stability. Based on the analyses, some technical support is provided to implement landslide prevention, mitigation and control measures such as filling cracks with grouting and widening the retaining wall.

On the Stability of Carbon Shale Slope under Rainfall Infiltration

Carbonaceous shale is a sedimentary rock containing a large amount of dispersed carbonaceous organic material. It is easy to crack and soften when exposed to water. In the present work, the stability of such a rock and its sensitivity to the formation of infiltrations due to rainfall are analyzed numerically using the GeoStudio software. The slope stability coefficient is calculated and verified using the landslide thrust calculation method. The results show that under the action of heavy rainfall, water infiltrates into the slope layer by layer, and, accordingly, the soil volume water content is different with respect to that typical of a homogeneous soil. It is also shown that, although in an initial stage, rainfall infiltration leads to the decline of the slope stability coefficient, with the progress of rainfall, this coefficient can temporarily increase, that is, these phenomena can display a lag phase.

Design of landfill liners for fine grained soils using CTRAN/W

The management and disposal of municipal solid waste (MSW) in many countries has changed significantly. To overcome the risk to environment and humans, landfills are designed and constructed to dump the waste in the ground and covered with soil, vegetation to protect the environment. Engineered landfills are provided with various liner systems. Liners used in the landfill acts as a barrier to water, leachate and other liquid materials. Liners also protect the ground from solute concentration. In the present study, compacted clay liners of various thicknesses are used. A numerical model of a landfill with the clay liner is designed and analysis is performed using GeoStudio software. In this software CTRAN/W module is used for contaminant transport analysis. From the landfill at different radial distances three bore holes are provided with varying depths respectively, also clay liner thicknesses of 0.5 m, 1.0 m, 1.5 m. Tests on the soil like standard proctor test and hydraulic conductivity tests are conducted. Results shows, with the increase in liner thickness, time taken by the contaminant transport to reach bore wells increases. Results also show the rate of variation in concentration of the leachate at each bore well in certain time period.

Effect of Rainfall Pattern and Crack on the Stability of a Red Bed Slope: A Case Study in Yunnan Province

Red bed slopes in the southwest of China are associated with a grant number of geological hazards, such as landslides, mud‐rock flows, and rock blocks falling, which are vital problems in geotechnical engineering. The damage can be induced or triggered due to a series of human and environmental activities, such as excavation, concentrated or long‐term rainfall, earthquake, and fluctuation of groundwater level. According to the field observations and geological exploration results, a small‐scale landslide was observed on January 10, 2016, after excavation along XiaoMo highway in Yunnan Province. A numerical model in actual size using GeoStudio software based on this typical red bed engineering slope was established in this study. Back analyses and laboratory tests were used to obtain the mechanical parameters of the geomaterial inside the slope. The historic rainfall data of Mengla County from July to September in 2016 was utilized as the flux boundary in analyzing the seepage variation features and the stability of the engineering slope in the rainy season. One major tension crack was set in the shallow region of the silty clay according to the geology survey to perform the disturbance of excavation on the geomorphology of the slope. Attempts were made to establish the anisotropic permeability of the crack induced by the complex fillings, and differences in the hydraulic response between the cracking and completed slope during the rainfall process were discussed. The result shows that the factor of safety of the slope without crack before the rainfall is 1.076, and the slope is considered in the state of the critical limit equilibrium, which is in accordance with the previous state of the slope under real conditions. The pore water pressure variations of the monitor points in the shallow region of the completed slope present close compliance with the rainfall intensity subjected to different rainfall patterns, which also controls the distribution of the plastic zone in the slope after rainfall. The comparisons in the seepage field and plastic zone between the cracking and completed slope reveal that the crack can shorten the infiltration path effectively, and the higher the permeability coefficient in the vertical direction is, the larger the pore water pressure increasing zone is and the higher the underground water level is, which should be paid more attention in highway constructions.

Unsaturated seepage and stability of double-layer slope under rainfall infiltration

Taking a homogeneous double-layer soil slope as an example, the SEEP/W module and SLOPE/W module in the finite element analysis software GeoStudio were used in this paper. Then, the changes of pore water pressure and stability under different rainfall patterns and soil parameters were studied. Finally, the variation curves of pore water pressure and slope safety factor with rainfall time were obtained. The results show that: Soil parameters a and m are directly proportional to the slope safety factor, while n is inversely proportional to the slope safety factor. Under the condition of continuous rainfall, the decreasing rate of slope safety factor is directly proportional to the rainfall intensity.Under different rainfall patterns, the continuous rainfall in the advanced and normal rainfall patterns will cause the slope stability to decline and then gradually recover, while delayed and averaged rainfall patterns rainfall will cause the slope stability to decline continuously.In addition, there is a lag period in the change of slope safety factor, and the whole lag period lasts about 6 hours. During the lag period, the pore water pressure inside the soil began to decrease, while the slope safety factor continued to decrease. The safety factor starts to recover after the lag period ends.

Slope stability and factor of safety analysis on different region of soil by using geo studio slope/w software

The one of the main trouble in the industry of construction is on account of topography nature and the weather conditions is Slope stability . Excavations, hill roads, railway lines, embankments, earth dams, open-cut mines, reservoirs and coastal slope stability these type of applications can come under the consideration of slope engineering. One of the frequent disaster is Slope failure which can generate great loss in property and life. The project namely “Slope Stability and Factor of safety analysis” gives analysis of Four region soil (Himalaya, Jammu and Punjab and on DTU, Delhi) using Geo Studio Slope/w software. The analysis for stability of earth structures can be get from a general software tool Slope/W which is design and develop accordingly. The main essential thing that must be taking care of in the slope stability is in order to undergo the mountainous region project. The study is focus on slope stability analysis for Himachal Jammu and Punjab State and Delhi soil slope using Slope/w. Slope failure has become one of the most frequent geological disaster along the road network in the hilly terrain of Himalayan Jammu , Punjab and Delhi regions that lead to huge loss of life, property and above all the environment. The process of slope stability is very important to defence of the slopes from failure and minimize the likelihood of failure of slopes. By helping Geo Studio(Slope/w) software, the factor of safety and slope stability slope stability will be analyzed.

Study of the Arching Ratio in Earth Dam by Comparing the Results of Monitoring with Numerical Analysis (Case Study: Marvak Dam)

Occurrence of arching phenomenon in the core of earth dams will reduce vertical stress, piping, and thus the destruction of the dam, so it is always considered an important issue in earth dams. In this study, GeoStudio software was used to investigate the total stress and the arching ratio of the Marvak earth dam at the construction and end of construction phase. In modeling the dam, the behavioral model of Mohr–Coulomb is used and the effect of layer-by-layer embankment construction is also considered. The results of total stress and arching ratio of instrumentation and numerical analysis in the construction and end of construction phase were evaluated and compared. Observational results and results of adaptive modeling show about 95%, which indicates the proper performance of the dam in terms of arching. The results show that with increasing embankment, the total stress also increases, and also, the highest percentage of arching from the beginning to the end of the construction phase is equal to 58% and occurred in the lower one-third of the core level. Due to the high impact of consolidation on arching, the speed and time of construction should be adopted in such a way that part of the consolidation of the lower embankment layers has been done, before the implementation and embankment of the upper layer. In the downstream of the clay core, a higher arching ratio (lower percentage of arching) is observed, which is due to the thicker filter and drainage areas.

Seepage and Slope Stability Analysis of Haditha Dam using Geo-Studio Software

The current study is designed to model seepage and slope stability analysis of Haditha dam (Iraq) using finite element method by GEOSTUDIO 2012 software. GEOSTUDIO software is capable to carry out analysis such as, stress-strain, seepage, slope stability, dynamic analysis. SEEP/W and SLOPE/W are sub programs of GEOSTUDIO which can simulate the movement and pore-water pressure distribution within permeable materials like soil and rock. In the present study Haditha dam, which is an earth dam constructed on the Euphrates River in the middle west of Iraq 7 km upstream from Haditha city in Al Anbar governorate with a total length of the barrier 9064 m was chosen as a case study to simulate the seepage and slope stability analysis. The input data given to the software are the geometry of the dam and its material properties. The flow net is generated by SEEP/W software showing phreatic line, equipotential line, and stream line. Also, the seepage influx is computed by the software. The dam at its actual design was investigated by inspected the water in the reservoir to be at maximum, minimum and normal water level. It was concluded that the dolomite core and the presence of asphaltic-concrete diaphragm and the grout curtain have an important effect on decreasing the seepage quantity through the dam body and the factor of safety values of upstream and downstream slopes stability satisfy the minimum limits for all levels of water.

Modeling assessment of seepage and slope stability of dam under static and dynamic conditions of Grindeho Dam in Ethiopia

This research work was carried out using Geo-Slope software programmes, i.e., to compute the infiltration and slope stability analysis of the Grindeho dam using SEEP/W and SLOPE/W. Embankment dam failure may occur due to different reasons, such as structural instability, hydraulic conditions, seepage through the dam body and foundation. The determination of the factor of safety for the dam slope stability and quantify the amount of seepage through the dam, under different cases of operations, is vital to ascertain the dam overall safety. In this research, Finite Element modelling is used through Geo-Studio software to simulate slope stability and seepage analysis of the embankment dam. Three distinct operational cases are considered for the dam analysis: end of construction before filling the reservoir, after/full reservoir condition, and rapid reservoir condition drawdown. Four separate methods of analysis were used to verify the stability of the slope embankment: Morgenstern-Price, Bishop, Janbu, and Spencer. The requirements of the Benchmark Safety Legislation (US Army of Corps Engineers and British Dam Society) are observed. The simulation results of the upstream and downstream side of the dam section have a direct effect on the factor of safety, the outcome of the stability analysis performed showed that all sections of the dam are safe within the specified range of factors of safety for the potential all loading and operation cases. But all the slip surfaces move through the section of the dam shell, which shows that this zone is the weaker zone and requires spatial attention. The simulation results obtained from the SEEP/W program revealed that 15,291.5 m3/year and 22,818.56 m3/year amount of seepage loss is present in the Grindeho dam during the drawdown case and full reservoir case, respectively.

Global study on slope instability modes based on 62 municipal solid waste landfills.

This study summarized global examples of landfill slope instability over the past 40 years, then selected 62 cases from 22 different counties to analyse the primary factors causing landfill instability. Three slope instability modes in landfill were categorized according to the position of the slip surface: (1) slip surfaces generated inside the waste pile; (2) slip surfaces that pass through the foundation soil; and (3) slip surfaces that occur along the interface between the bottom liner and the municipal solid waste (MSW) pile. These three types of slope instability modes account for 69.4%, 19.32% and 11.28% of all slope instability, respectively. Moreover, five primary causes of landfill instability were identified. A high landfill leachate level was the dominant cause, accounting for 40.32% of cases. This was followed by inadequate compaction of MSW, which accounted for 22.58% of cases, and insufficiently bearing capacity of the foundation, which accounted for 19.35% of cases. Moreover, low shear strength of the liner-MSW interface and rapid release or deflagration of landfill gas were critical factors affecting landfill stability. Factors of safety were calculated using GeoStudio software for selected landfills in China (Maoershan and Xiaping) and Sri Lanka (Meethotamulla). Results from this study are expected to contribute to the prevention and control of landfill failure.

EVALUACIÓN DEL FACTOR DE SEGURIDAD EN TALUDES DE TERRAPLENES CARRETEROS ALTOS ANTE CARGA SÍSMICA

Cuando se construye un terraplén carretero, una de las variables analizadas en el diseño es la obtención del factor de seguridad para determinar la estabilidad y seguridad de los taludes. Este diseño se realiza haciendo uso de un análisis estático y, en casos más específicos y aislados haciendo un análisis sísmico. En el presente trabajo se realiza un estudio del comportamiento del factor de seguridad en taludes de terraplenes carreteros altos frente a la solicitación sísmica. Para llevar a cabo el presente estudio se realizó un diseño de experimento 32. En el diseño de experimento se varió la altura del terraplén en tres niveles y el nivel de sismicidad, construyendo acelerogramas a partir de los espectros de diseño considerando los parámetros de la sección 3.1 del Manual de diseño de obras civiles de la comisión federal de electricidad de México. En la obtención de los resultados se empleó el método de los elementos finitos (MEF) y el método de Newmark. Como herramienta computacional se empleó el software especializado Geo-Studio con el sub-módulo para el análisis dinámico QUAKE/W, y el sub-módulo para el análisis de estabilidad SLOPE/W. Los resultados obtenidos muestran la necesidad de revisar estas obras frente al sismo sobre todo en zonas de sismicidad alta cuando su altura supere los 12 m.

Finite Element Analysis of Seepage for Hemrin Earth Dam Using Geo-Studio Software

Finite Element Approach is employed in this research work to solve the governing differential equations related to seepage via its foundation's dam structure. The primary focus for this reason is the discretization of domain into finite elements through the placement of imaginary nodal points and the discretization of governing equations into an equation system; An equation for each nodal point or part, and unknown variables are solved. The SEEP / W software (program) is a sub-program of the Geo-Studio software, which is used by porous soil media to compensate for the problems of seepage. To achieve the research goals, a study was carried out on Hemrin dam, which located in the Diyala River 100 km northeast of Baghdad, Iraq. Thus, one cross-section is selected for different elevations (minimum, normal and maximum or flood design elevations) to compute the seepage of water, pore water pressure and phreatic line. By theoretical analysis appeared that when the water reservoir was connected to the flood level, a problem may occur in the downstream face of the dam lead to seepage failure. A set of solutions checked by using the Geo-Studio software has been suggested in this research to solve this problem. In addition, and by analytical approach SLOPE/W (a sub-program of the Geo-Studio software) are used to assess the stability of the downstream slope and calculation factor of safety.

Influence of intrusive granite dyke on rainfall-induced soil slope failure

Intrusive granite dykes and their weathered layers can have great effects on seepage into slopes and on their stability. However, few studies of this topic have been reported. Using the Zhonglincun landslide as an example, we investigate the impact of a dyke and its weathered layer on the formation mechanism of a rainfall-induced residual soil slope failure. The sliding mass of Zhonglincun landslide is mainly composed of residual soils of both tuff and an intrusive granite dyke. We used laboratory soil column tests to obtain rainfall infiltration characteristics of the two residual soils. The SEEP/W mode of Geo-studio software was then used to replicate the above soil column tests to back-analyze unsaturated hydraulic parameters of the two soils, which were later used to simulate seepage fields and stress-strain fields of the slope under Typhoon Tailim. The results indicate that the movement of rainwater in the residual soil of the granite dyke is much faster than that of the residual soil of the tuff. Rainwater infiltrates rapidly into the granite soil, and then flows laterally into the tuff residual soil, raising the groundwater table in the slope, especially near the contact between the two residual soils. This leads to a rapid increase in pore-water pressure and initiates the serious deformation of the landslide. The granite dyke and its residual soil have played a key role in the formation of Zhonglincun landslide.

Analysis of stability factors and interaction rules of soil slope under heavy rainfall

Short-term heavy rainfall is an important inducement factor of soil landslide disaster in southern China. In order to study the influence degree of different factors on slope stability under heavy rainfall conditions, combining numerical simulation and mathematical statistics method, taking a certain slope in Guangzhou as the engineering background, the slope stability coefficient was calculated based on the coupling of Seep/W and Slope/W modules in Geo-studio software. Then the orthogonal experiment designed by Minitab was used to select rainfall intensity, rainfall time, cohesion, internal friction angle and severity for univariate range and variance analysis. On this basis, the rainfall intensity, rainfall time and internal friction angle were selected for the multi-factor interactive analysis. The results show that the five factors have significant influence on the slope stability. The order of sensitivity is: angle of internal friction of residual soil > rainfall intensity > rainfall time > cohesion > heavy. The interaction between the Angle of internal friction and rainfall has a high influence on the slope stability. The effect of interaction on slope stability should be emphasized in slope warning.