Seepage Water Research Articles

Water Seepage in Rocks at Micro-Scale

To complete groundwater diversion, the complex flow law of groundwater in rocks must be investigated so that groundwater diversion can be improved. This research uses the computer finite element method (FEM), CT scanning calculation method, Avizo method, and digital core technology combined with the Fluent calculation method (FCM) to reconstruct rocks with microscopic pore structures on a computer. The numerical simulation results under different conditions show that: the total pressure change gradually decreases under different pressure gradients. In a seepage channel, the seepage path does not change with the change in seepage pressure, and the seepage velocity is the largest in the center of the pore. The longer the seepage path is, the greater the decrease in seepage velocity. Different seepage directions have similar seepage laws. The research results provide effective guidance for the project to control groundwater.

Numerical Simulation of Well Type Optimization in Tridimensional Development of Multi-Layer Shale Gas Reservoir

Aimed at the development of shale gas reservoirs with large reservoir thickness and multiple layers, this paper carried out a numerical simulation study on the optimization of three different well types: horizontal well, deviated well, and vertical well. To make the model more in line with the characteristics of shale gas reservoirs, a two-phase gas–water seepage mathematical model of shale gas reservoirs was established, considering the adsorption and desorption of shale gas, Knudsen diffusion effect, and stress sensitivity effect. The embedded discrete fracture model was used to describe hydraulic fracture and natural fracture. Based on Fortran language, a numerical simulator for multi-layer development of shale gas reservoirs was compiled, and the calculation results were compared with the actual production data of Barnett shale gas reservoirs to verify the reliability of the numerical simulator. The spread range of hydraulic fractures in the reservoir with different natural fracture densities is calculated by the simulation to determine well spacing and fracture spacing. The orthogonal experimental design method is then used to optimize the best combination of well spacing and fracture spacing for different well types. The results show that the well productivity of the high-density (0.012 m/m2) natural fractures reservoir > the well productivity of the medium-density (0.006 m/m2) natural fractures reservoir > the well productivity of the low-density (0.001 m/m2) natural fractures reservoir. According to the design of the orthogonal test, it can be seen that the most significant factor affecting the productivity of horizontal wells is the fracture spacing in the Y direction. For deviated wells and vertical wells, the X-direction well spacing has the greatest impact on its productivity.

Upscaling Hydrological Processes for Land Surface Models With a Two‐Hydrologic‐Variable Model: Application to the Little Washita Watershed

AbstractLand Surface Models (LSMs) are key components of Earth System Models, which the Intergovernmental Panel on Climate Change relies on in many of their studies. However, these models either neglect or oversimplify basin‐scale hydrological processes that produce the land surface water balance. Bringing the dominant physical processes from the local scale up to the LSMs presents a significant challenge for improving the models. This article presents an upscaling (or bottom‐up) approach to identify the basin‐scale driving variables that need to be exported into LSMs. The approach is developed on the Little Washita Watershed (OK, USA) using 20‐year hydrology (1993–2013). A physically based 3D model built with HydroGeoSphere first produces a reference simulation. An equivalent hillslope model is then able to capture both 3D simulated water balance and local water table dynamics with reasonable accuracy. The physical analysis of the water balance in the different hillslope compartments leads to the identification of two driving variables: seepage face extension and water table slope. The two variables are then implemented in a conceptual model. Results show a good capacity of this model to capture the water balance of hillslopes having different lengths and slopes. Moreover, the model is able to capture the water balance of the reference simulation with reasonable accuracy. The proposed approach thus reduces the 3D watershed model to a two‐variable conceptual model that constitutes a basis for developing an improved LSM hydrology.

THE OPTIMUM LOCATION OF CONCRETE SHEET PILES UNDER HYDRAULIC STRUCTURE AFFECTED THE SEEPAGE WATER PRESSURE USING ANSYS PROGRAM

The problem of water seeping through the earth dams or under concrete structure is regarded one of the main reasons of the structures’ failure. This may be due to the failure in soil layer on which the hydraulic structure is constructed or due to the water pressure resulting from a difference in the level of the upstream and downstream. In previous studies have found that the use of concrete sheet piles under the dams is one of the effective solutions to control the seepage of water under structures, this study considers that control of this problem is by using sheet piles. The 2-D F.E. model ANYSIS Program, has been used to analyze the effect of the optimum location of concrete sheet piles affected on seepage water pressure underneath hydraulic structures, when the stability against seepage water pressure against piping were calculated in different cases. The results showed the water pressure reduce, when the sheet pile downstream is used at 60° and depth 6m

THE OPTIMUM LOCATION OF CONCRETE SHEET PILES UNDER HYDRAULIC STRUCTURE AFFECTED THE SEEPAGE WATER PRESSURE USING ANSYS PROGRAM

The problem of water seeping through the earth dams or under concrete structure is regarded one of the main reasons of the structures’ failure. This may be due to the failure in soil layer on which the hydraulic structure is constructed or due to the water pressure resulting from a difference in the level of the upstream and downstream. In previous studies have found that the use of concrete sheet piles under the dams is one of the effective solutions to control the seepage of water under structures, this study considers that control of this problem is by using sheet piles. The 2-D F.E. model ANYSIS Program, has been used to analyze the effect of the optimum location of concrete sheet piles affected on seepage water pressure underneath hydraulic structures, when the stability against seepage water pressure against piping were calculated in different cases. The results showed the water pressure reduce, when the sheet pile downstream is used at 60° and depth 6m.

Vectors that spread malaria: introduction to the microbiome-science of mosquitoes

Amongst six main mosquito species, Anopheles minimus responsible for transmitting malaria in India. Anopheles minimus is predominant in India particularly northeastern regions and is most accountable for focal infection outbursts marked by an increase in Plasmodium falciparum diseases, and further deaths that can be directly linked to them. According to genetic analysis, Anopheles minimus (formerly species A) is the most common species occurring in India, involving the north-eastern provinces and the East-central Odisha state, out of the three species that make up the Minimus Complex, which is distributed throughout Asia. It is documented throughout the year and explains perennial transmission as shown by records of sporozoite infections. This species has been observed spawning year-round in slow-moving seepage water streams. It is also primarily endophilic and endophagic. Malaria is still a serious public health concern in many parts of the world, especially in tropical areas. It is a vector-borne infectious disease. The protozoan parasite Plasmodium, which causes malaria, is spread via the bite of female Anopheles mosquitoes carrying the infection. Insecticide-treated nets (ITNs) and indoor residual spraying are the major methods used in the control interventions aimed at mosquito vectors that have shown great success over the past 20 years (IRS). Unfortunately, natural mosquito populations are developing resistance to the conventional pesticides now employed in public health, which is impeding the efficacy of the existing vector management measures over the long run. Therefore, it appears vital to enhance vector control strategies through the creation of novel, environmentally friendly methods in order to reach the objective of eliminating malaria. Our review article provides background for describing the biology, information gaps, and possible public health danger of Anopheles viruses.

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.

Experimental Study on Grouting and Flow Characteristics of Rough Vertical Fractures

It is of great engineering significance to study the seepage characteristics and flow field distribution of rough fractured rock masses for grouting to stop leakage. Through the visual fracture seepage test device we developed, the visual seepage characteristics of tension fractures under vertical angles and different stress paths of grout and water were studied. Through silica gel secondary mould turning technology, the fracture morphology is accurately reprinted; based on GIS simulation technology, the visualization of the fracture surface spatial data is realized; the actual seepage area and flow path of the fluid are measured accurately by using digital image self-recognition technology, and the variation law of the grout and water seepage area under the coupling of normal stress and water pressure is obtained. Through visualization, it is pointed out that, with the increase of normal stress, the fracture water can be divided into three stages, archipelago flow, transition flow, and groove flow, while the grout has no capillary permeability and no archipelago flow effect because of its high viscosity. The critical point of grout antiseepage is defined and calibrated by data. Based on the analysis of the cross-sectional velocity of the groove flow, it is pointed out that the relationship between the velocity on the flow path and JRC is an exponential function. The main flow path is mainly distributed in the area where the JRC is relatively small. As the normal stress increases, the first deflection point of the grout flow path appears in the maximum region of JRC (6.42); the secondary deflection point appears in the second largest region of the flow path JRC (4.53), and the fluid of deflection point has the maximum kinetic energy on the main flow path. The current study can accurately obtain the relevant parameters of vertical fracture grouting seepage characteristics and provide theoretical guidance for solving the key scientific problems in grouting engineering, such as invisible flow paths and unmeasurable velocity vectors.

Behaviour of geocomposite as a packing material in the back of weepholes

The purpose of retaining wall is used to retain the soils of different elevations. The weepholes are present along the retaining wall to facilitate seepage of water collected in the backfill soil. The purpose of weepholes is to drain the water through drainage constructed along the bottom of the retaining wall. The main factors influencing the seepage in a retaining wall are surface water entry, seepage in utilities and sudden rise in the water table. In this study, the behaviour of weepholes is when a geocomposite is placed in the back of the retaining wall is studied and which is compared to the conventional. Weephole is packed with larger particles in its back. The geocomposite used in the study is a laboratory fabricated material and it is a low density polyethylene with perforation. The test is conducted for two different types of soil; i. soil with specified relative density and ii. Soil with in-situ density. The behaviour of weep holes for the two different soil with a geocomposite is different. Numerical analysis is done to understand the deformation and the pressure along the wall.

Spatial variation in groundwater quality with respect to surface water seepages in Kadhan area District Badin (Indus Delta), Sindh, Pakistan

Spatial variation in groundwater quality with respect to surface water seepages in Kadhan area District Badin (Indus Delta), Sindh, Pakistan

Experimental investigation of the failure mechanism of deep granite under high seepage water pressure and strong unloading effect

Experimental investigation of the failure mechanism of deep granite under high seepage water pressure and strong unloading effect

Mechanical Strength, Water Seepage and Microstructure of a Novel Landfill Solidified Sludge Liner Material

In order to prepare a novel landfill liner material, we used industrial calcium-containing waste (slag, fly ash, and desulfurized gypsum) to solidify municipal sludge. The mechanical and permeability properties of the solidified sludge material (SSM) were evaluated using straight shear, uniaxial compression, and permeability tests. The hydration products, microscopic morphology, and elemental composition of the SSM after the wet and dry cycles were analyzed using a combination of scanning electron microscopy (SEM + EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The SSM has high strength and low hydraulic conductivity. The values of cohesion c and internal friction angle φ reached 0.45–3.31 MPa and 6.52–36.28°. The SSM exhibited a compressive strength of 0.93–11.67 MPa and hydraulic conductivity of 4.80 × 10−9–1.34 × 10−7 cm/s. Analysis shows that SiO2, Al2O3, and CaO in industrial calcium-containing solid wastes and sludges produce dense bulk and agglomerated C-S-H and C-A-S-H gels under alkali excitation. The optimum ratio of sludge, desulfurized gypsum, fly ash, and slag in the solidified sludge was 1:0.61:0.62:0.54, whereas the optimum exciter was Ca(OH)2. The SSM may be used as a good barrier material to prevent water seepage in landfills.

Microstructure, Shrinkage, and Mechanical Properties of Concrete with Fibers and Experiments of Reinforced Concrete Beams without Shear Reinforcement.

The current findings on concrete with fibers show that research has focused primarily on individual aspects, especially in terms of mechanical properties and structural uses. However, no broader view of the problems solved has been provided. In this study, we present a conceptual overview of a new, comprehensive experimental program for the assessment of fiber-reinforced concrete, which includes the analysis of microstructural and structural elements, as well as specific features such as shrinkage and resistance to pressurized water. The proposed experimental program included several variants of schemes for the dosing of fibers into concrete, using steel fibers that were short and straight. Fiber dosing was performed up to 110 kg/m3. The basic tests performed included tests of the compressive strength of concrete, and of the split and flexural tensile strength for different dosing amounts. Within the structural tests of reinforced concrete beams without shear reinforcement, two variants of spans with different degrees of reinforcement were implemented. Herein, the test results are evaluated graphically with a detailed analysis of the positive effect of fibers, and we also provide general recommendations for the structural uses of the fibers used and the design of fiber-reinforced concrete structures. Among the important results of this experimental program was the observation of a significant increase (of the order of tens) of the percentage of the split tensile strength and an increase of the overall load-bearing capacity of the reinforced concrete beams without shear reinforcement. Among the important aspects of our findings is the fact that a fine-grained concrete mixture was used, which increased resistance to pressure water seepage, and therefore, the effect of shrinkage can be influenced by the method of production and the treatment of the concrete used. We also provide detailed figures of the microstructure.

Prediction of Water-Blocking Capability of Water-Seepage-Resistance Strata Based on AHP-Fuzzy Comprehensive Evaluation Method—A Case Study

Coal mining under the aquifer in Northwest China has brought a series of ecological problems, such as the decline of groundwater levels and the death of surface vegetation. The study of the impermeability of rock strata between coal seams and the overlying aquifers is of great significance to solve these problems and realize water-preserving coal mining (WPCM). Based on mining-induced overburden damage and permeability deterioration, the concept of the “three seepage zones” of overburden is proposed, namely the pipe flow zone, water seepage zone and nominal water-seepage-resistance zone (NWSRZ). Meanwhile, the concept of water-seepage-resistance strata (WSRS) is put forward from the aspects of initial permeability, structural strength, swelling and the stratigraphic structure of the overlying strata. AHP-fuzzy comprehensive evaluation (AHPF) is employed to construct a model to evaluate the water-blocking capacity (WBC) of the WSRS. The model includes three secondary factors and nine tertiary indicators, and the weights and membership functions of the indicators are determined. Subsequently, the model is generalized and applied to the Yu-Shen mining area. The membership degrees are spatially visualized by means of thematic maps. The comprehensive evaluation values Φ of the WBCWSRS of 400 boreholes in the mining area under backfill mining, narrow strip mining, slice mining and longwall cave mining are calculated. Then, the Kriging method is employed to plot the zoning maps of Φ under four different mining methods. In view of different grades of WBCWSRS, three corresponding countermeasures, i.e., mining methods optimization, curtain grouting and underground reservoir construction, are put forward. The fluid–solid coupling embedded in FALC3D software is employed to establish a numerical calculation model to simulate the water table fluctuation of the underground aquifer under the four mining methods, and the reliability of the model is verified indirectly. In this paper, mathematical theory is combined with WPCM to develop an evaluation model of WBCWSRS, which provides a reference for the coordinated development of coal extraction and water resource preservation in arid and semi-arid mining areas.

Research on Formwork Erection Construction of Non Combined Through Wire Water Stop Screw of Impermeable Wall

The threaded rod without water stop plate is used to replace the original water stop bolt. The threaded rod is composed of a full-length threaded rod, a tapered screw sleeve and a nut. With the help of the threaded rod, the water seepage path of the wall is changed, the water seepage line is extended, and the water pressure is reduced, so as to achieve the water stop effect. Its implementation not only reduces the processing difficulty, but also can adjust the bolt buckle spacing according to the thickness of the outer wall of the basement, effectively strengthen the formwork, and reduce the risk of formwork expansion and explosion; It can be manually removed to reduce on-site hot work. It is a better choice for the basement wall formwork system.

Pollution Characteristics and Risk Assessment of Heavy Metals in the Bioretention Systems of Sponge Cities

As an important water purification and seepage measure for sponge cities, biofiltration systems have been widely used in their construction in China. In order to identify the heavy metal accumulation, pollution, and its potential environmental risk in the biofiltration systems, this study examined the heavy metal contents and spatial distribution characteristics by taking the biofiltration systems of Yuelai new town, Chongqing, the first demonstration area of sponge city construction in China, as the research object, and conducted a risk evaluation of the pollution level and ecological environment in this new town using the contamination factor (CF), geo-accumulation Index (Igeo), and potential ecological risk coefficient (PERC). The results showed that, except for Mn, the average contents of Cu, Zn, Pb, Ni, and Cd in the biofiltration systems of Yuelai new town were 4.14, 1.77, 4.98, 1.23, and 6.51 times higher than the soil background values of Chongqing. In terms of spatial distribution, the contents of heavy metals in biofiltration systems along the roads in different functional areas showed great differences. The contents of Cu, Zn, Mn, Pb, Ni, and Cd in the industrial area were significantly higher than those of the same types of heavy metals in the biofiltration systems in other areas (P<0.05). The CF and Igeo showed that the pollution level of heavy metals was ranked as follows:Mn<Zn<Ni<Cu<Pb<Cd. Among them, Cu and Pb were highly polluted, Cd was severely polluted, and the PERC of Cd was 194.13, which indicated a high risk; the remaining heavy metals were at a minor risk. The pollution contribution of Cd to the composite PERC of all heavy metals was 78.73%, which was the major source of heavy metal potential risk. After the long-term operation of the biofiltration systems in a sponge city, certain environmental and ecological risks may exist later due to the accumulation of filler heavy metals. Hence, it is necessary to strengthen the operation management and carry out research on the non-polluted management of the filler of biofiltration facilities, to prevent them from becoming a new source of urban heavy metal pollution.

Analysis of Drainage System for Overcoming Floods on Untung Jawa Island, South Thousand Islands District, DKI Jakarta

In general, drainage can be used to reduce excess water, whether from rainwater, seepage, or excess irrigation water from an area, so that the function of the area is not disturbed. This study aims to analyze and examine the drainage problems that exist on Untung Jawa Island, South Seribu Islands District, DKI Jakarta, the drainage channels are poorly maintained and frequent flooding. The data used in this study are primary and secondary data, in planning the calculation of flood discharge a 2-year return period is used. For the calculation of flood discharge, the plan uses a rational method and is added to household flood discharge, and the results will be compared with the existing condition of the drainage channel on Untung Jawa Island, South Thousand Islands District, DKI Jakarta. The results obtained that the largest design flood discharge is 3.277 m3/second on channel A8 and the smallest design flood discharge is 0.094 m3/second on channel C5. for the existing condition of the drainage channel, there are 11 channels that fall into the unsafe category because the condition of the existing channel capacity is less than the planned flood discharge, namely channels A2, A3, A4, A5, A6, A7, A8, A10, B2, B3 and B4. Infiltration wells are planned to accommodate the excess flood discharge, and it takes 19 infiltration wells on channel B4, 13 pieces on channel B3, 9 pieces on channel A8, 6 pieces on channel A2, A3, A6 and B2, 4 pieces on channel A7 , 2 pieces on channel A10, 1 piece on channel A4 and A5.

A Study on the Generation Mechanism and Development Process of Piping Based on the Theory of Muddy Water Seepage

In the process of piping development, the sediment carried by seepage causes the change of porosity and then causes the change of permeability coefficient. Therefore, piping belongs to muddy water seepage (i.e., unstable seepage). Based on the theory of muddy water seepage, the new control equation of piping model is established. The generation mechanism and development process of piping for white fine sand and sand gravel are explored. The advantages for the new control equation of piping model are discussed. The results show that the new control equation of piping model is not only simpler in form but also easier to solve and can better describe the characteristics of piping generation, development, and stability. Compared with white fine sand (the initial relative density and porosity are smaller, and the initial permeability coefficient and critical gradient are larger), the porosity, permeability coefficient, seepage flow, and sediment volume of sandy gravel increase faster with time. When the porosity is the same, the permeability coefficient, seepage flow, and sediment volume of sand gravel are larger. The smaller the area affected by piping, the faster the increase of porosity, permeability coefficient, seepage flow, and sediment volume. When the porosity and permeability coefficient are the same, the seepage flow and sediment volume are smaller. The smaller the initial porosity and permeability coefficient, the later the generation, and development of piping. It can provide a reference for piping danger forecast and emergency response.

Study on Construction and Reinforcement Technology of Dolomite Sanding Tunnel

The No. 2 conduit of the Xiaopu Tunnel in the Yuxi section of central Yunnan’s water diversion project is taken as the research object, starting from the geological conditions along with the characteristics, formation mechanism and evolutionary model of dolomite sanding. This paper discusses the engineering problems of the project’s tunnels with dolomite sanding in the water-rich section, and its corresponding engineering reinforcement plan. It was found that in the tunnel section with normal level of dolomite sanding, there was no water seepage, where measures such as advanced small conduit, mechanical excavation, short grubbing and strong support could all be adopted for safe passage. Even in the water seepage section of the weak dolomite sanding tunnel, the surrounding rock was found in close interlock with strong self-stability. The excavation and support were implemented according to the category of normal surrounding rock. In the water-rich sections with strong and intense dolomite sanding, gushing of water and sand were quite frequent, with developed fissures, broken rock masses and rich waters. During the engineering operation, phosphoric acid and sodium silicate slurry in addition to urea formaldehyde resin and oxalic acid slurry plus Malisan and liquid catalyst slurry were first prepared for water plugging. Then, pure water slurry was used for surrounding rock reinforcement, which exerted an excellent effect. This method can provide reference for reinforcing tunnels of sandy dolomite in other areas of projects.

Analysis of the drainage characteristics of different graded asphalt mixtures

ABSTRACT This study investigates the drainage characteristics of different asphalt mixtures in different directions using a new selfmade water seepage test device. Among them, the pavement drainage characteristics of five aggregate gradations were analyzed, which include asphalt concrete (AC-20), stone matrix asphalt (SMA-20), SUPAVE (SUP-20), and open-graded frictional course (OGFC-13 and OGFC-16). In addition, the effect of the void ratio on the drainage characteristics of different asphalt mixtures was analyzed based on the results of the permeability test. Finally, the gray correlation theory was applied to rate the relationship between different sieve passage rates and drainage properties of asphalt mixtures. The results of the study show that the transverse flow is larger than the longitudinal flow and plays a major role in the drainage process. The water volume is negatively correlated with the permeability coefficient of variation (CV). In addition, the permeability CV in all directions shows a gradual decrease with the increase of the permeability coefficient.