Water-saturated Soil Research Articles

APLIKASI METODE GEOLISTRIK RESISTIVITAS UNTUK ANALISIS BIDANG GELINCIR DAN STUDI KARAKTERISTIK LONGSORAN DI JALAN RAYA SUBAN BANDAR LAMPUNG

Pidada Urban Village, Panjang District, Bandar Lampung is an area that has medium to high landslide potential. One of landslides prone area triggered by rain located on Jalan Raya Suban. The slip surface areas under water-saturated soil is one of causes of landslides triggered by rain. Geophysical method used to detect slip surface is 2D Resistivity Method of Wenner-Schlumberger Configuration. In this study, an analysis of the slip surface has been carried out with the 2D resistivity method of the Wenner-Schlumberger Configuration and determination characteristic of landslide on Jalan Raya Suban. Based on the results of study indicated that the subsurface lithology consists of layers of tuff sediment, sandy clay and breccia. The slip surface is estimated at the boundary the layers of tuff sediment layer and sandy clay with depth (5-15) meters from the ground surface. The results of analysis and observation showed that type of landslide is translational fine-grained soil. Types of slope reinforcement that can be applied are civil and vegetative techniques.

Kinetics of filtration consolidation of water-saturated clay soils

The relevance of the research processes filtration consolidation due to the place of water-saturated soils in various design solutions related to the exploration, production and transportation of hydrocarbons. It should be noted that the diversity of soils led to the emergence of a wide range of mathematical models, obtained on the basis of generalization of experimental data and various assumptions to simplify engineering calculations. The article presents the results of theoretical and experimental studies of the mathematical model of the consolidation process of a water-saturated porous medium. This model is based on simplifying assumptions that are different from those adopted in well-known solutions. A fundamental approach to the formation of the model was developed on the basis of the kinetic representations of chemical reactions used in solving the environmental problems of epoxidation reactions of olefins. We determined the parameters of the mathematical model of the consolidation process of the saturated porous medium of clayey soil and confirmed its adequacy by the research results. In addition, we established the parameters of the field of non-equilibrium filtration, reducing the nonexistent ability of water-saturated soils.

Improving the physical and mechanical properties of fortified soil for road construction in the forest zone

In order to purposefully control the processes that determine the formation of the structure and properties of cement soils, studies were carried out on the strengthening of soils with Portland cement with a water-soluble additive hydropropylene emulsion (WHE). The purpose of the laboratory studies was to study the change in the ultimate strength in compression, water saturation and frost resistance of cement soils, depending on the particle size distribution of the original soil, the amount of mineral binder - Portland cement and the WHE additive. Based on the results of the research, soil strengthening with Portland cement with WHE additive allows to form a complex crystallization-coagulation structure of materials with the required values of compressive strength, water saturation and frost resistance, depending on the dosages of binding components for given climatic and transport-operating conditions. The effectiveness of the WHE additive increases with increasing dispersion of soils, so the technology of strengthening of clay soils in conditions of wet and acidic soils of the forest zone for the construction of forest roads is promising.

Practical restoration-related experience with creation of basement level and underground parking into and near architectural monuments in down-town of Saint-Petersburg

Geotechnical construction in Saint-Petersburg is governed by the specific features of geological conditions. There is large thickness of soft water saturated soil underlays at the basement monuments and historical buildings. This soft water saturated soil become thixotropic under insignificant dynamic effect (construction action, transport, seasonal freezing and etc). The experience of the renovation, reconstruction old buildings with construction of the deep basements, underground parking in the inner yards or near the architectural monuments in the central part of Saint- Petersburg are given in this article. This paper provides the description of geotechnical solutions, which were realized on the various cultural heritage buildings, such as Catholic Church of St.Catherine on the Nevsky prospect, Taurid Palace, Christmas Church on the Sands, shopping mall «Galeria» on the Ligovsky prospect. The authors analyzed some failures of buildings and facilities as the result of incorrect methods and technologies of the deep excavation.

Climate change and redoximorphosis in a soil with stagnic properties

In soils with perched water tables, frequent changes between reducing and oxidizing conditions result in the formation of redoximorphic features (RMF). Perched water tables are linked to the presence of a low water-permeable soil horizon and high water input by precipitation. Precipitation, however, is strongly affected by climate change. Hence, we postulate that soils with a perched water table are particularly vulnerable to climate change. To verify this hypothesis, we set up a monitoring campaign from April 2014 to October 2019 at a forested Planosol in North Rhine-Westphalia, Germany. On an hourly basis, the redox potential (EH) and air-filled pore volume (ε) were measured in four soil depths. Furthermore, we calculated the CWB and employed two future climate scenarios for the years 2071–2100 to discuss the consequences for RMF formation. Reducing conditions were evident in the moist hydrological winter of 2015 and 2016, while oxidizing soil conditions (EH > 300 mV at pH 7) prevailed throughout the drier years (2017, 2018, 2019) for the whole soil profile. Concomitant with an increase in ε during spring, we observed a switch from reducing to oxidizing soil conditions at low ε of 0.01–0.03 cm3 cm−3 in the temporarily water-saturated soil horizons. At present, reducing soil conditions are limited during early spring during which manganese and iron can be mobilized from their oxides. Thus, RMF actively form but the CWB forecast until 2100 indicates a lower water input, which will diminish the period for redox-induced mineral dissolution. This study provided the essential information that soils with a perched water table are specifically vulnerable under progressing climate change. Presumably, RMF become more and more relictic that needs to be validated in the future.

The role of phosphorus in growing tomatoes in near water-saturated soil

High-yielding, waterlogged cultivations with considerable nitrogen input are widely practiced in Kyushu Island, Japan. Our objective was to determine the role of available phosphorus in relation to nitrogen and soil microorganisms on tomato growth in such systems. Tomato seedlings were grown in a pasteurized soil with ample KNO3 in addition to different amounts of sodium or potassium phosphates to assess effects of phosphorus on growth enhancement and water-use efficiency in the seedlings grown with copious soil water (>－0.7 kPa). Both monobasic and dibasic phosphates applied at 40 mM to near-saturated soil markedly promoted seedling growth when fertilized with 120 mM KNO3 or NH4Cl, but not in the soil without nitrogen. The final concentration of NO3－ near the soil surface was maximized in the nitrated soil with no added PO43－ but declined significantly when fertilized with any phosphates except Na2HPO4. No significant accumulation of NO3－ was detected in the water-saturated bottom soils regardless of soil fertilization with any plant minerals. Increased seedling growth was accompanied by lower dry root/shoot ratios and marked increases in evapotranspiration efficiency. Such positive effects of PO43－ were greater with NO3－ than NH4＋ but diminished with increased concentrations of Na＋ up to 160 mM. Nonetheless, growth promotions by ample NO3－ with PO43－ were nearly negated in the non-pasteurized soil. Apparently, the activities of indigenous soil microbes were more significant than soil nitrogen and phosphorus in limiting the growth potential of tomato plants in near-saturated soils.

Productivity of soybean varieties (Glycine max (L.) Merill) in vegetative phases V4 and generative phases R1 classified waterlogged conditions by application of GA3 and salicylic acid (SA)

Water-saturated soil conditions or waterlogging conditions can cause a decrease in soybean productivity. Efforts to destroy crop loss due to inundation through cultivation techniques are considered acceptable so that need for good management in soybean cultivation. This study aims to expression at the productivity results of the three varieties namely Deja-1, Dering, and Anjasmoro with the inundation stress in the vegetative phases V4 and generative R1 phases with the use of Gibberellic acid (GA3) and Salicylic acid (SA). The submergence time is given for 72 h in the stated phase. The use of GA3 and Salicylic acid was given with 3 levels of concentration treatment namely GA3 (150 ppm) + salicylic acid (100 ppm), GA3 (200 ppm) + salicylic acid (150 ppm), and GA3 (250 ppm) + salicylic acid (200 ppm). The outcomes showed the application of GA3 and salicylic acid showed good production in the number of pods, number of seeds, and weight of seeds. However, the pressure of waterlogging affects the duration of flowering time so that it can cause loss of production.

Analysis on hydraulic characteristics of improved sandy soil with soft rock.

Hydraulic properties of sandy soil from the Mu Us sandy land of Shaanxi Province were analyzed by using SEM technology. Soil porosity, the water characteristic curve, and unsaturated hydraulic conductivity of aeolian sandy soil with added soft rock were analyzed, and fractal characteristics were established. Soil hydraulic properties revealed the effect of soft rock application on soil structure and hydraulic properties. Mass ratios of soft rock to aeolian sand were 1:5, 1:2, and 1:1. Results showed that the addition of soft rock can significantly increase the bulk density of sandy soil and reduce the total porosity and macroporosity. The mass fraction of water-stable aggregates greater than 0.25mm increases significantly, increasing the fractal dimension of soil pores; reducing the soil saturated water content and saturated hydraulic conductivity. SEM technology and pore fractal theory were used to predict the soil salinity curve and unsaturated hydraulic conductivity of the improved saline soil.

Temperature characteristics and influence of water-saturated soil resistivity on the HVDC grounding electrode temperature rise

The temperature rise process has always been the main factor for the safe operation of high-voltage direct current (HVDC) grounding electrodes, and the soil resistivity is the key parameter affecting the temperature rise of the grounding electrode. In some region where rainfall is high or groundwater is abundant, the soil moisture content at the electrode site may be very high or saturated. Therefore, studying the temperature characteristics of soils with saturated water content (water-saturated soil) for grounding electrode heating is particularly important. In this study, the resistivity measurement of temperature rise was conducted on different types of water-saturated soil. On the basis of this measurement result, an electro-thermal coupling finite element model of grounding electrode in water-saturated soil was established. Then the reliability of the coupled model is verified through an experiment of the vertical electrode in water-saturated soil. The comparison of experimental and simulation results shows that the maximum temperature error is 3.5%. Finally, the influence of water-saturated soil resistivity on practical engineering application was analyzed. Under the condition of water-saturated soil, the saturation of electrode temperature rise curve gets more pronounced as the current injection time increases. Thus, the temperature rise rate of the actual grounding electrode is lower than the calculation result without considering the water-saturated soil resistivity. Therefore, using the temperature characteristics of water-saturated soil resistivity to simulate the temperature rise of the grounding electrode can provide a theoretical basis for the grounding electrode to work under water-saturated soil conditions.

Sorption of Polyfluoroalkyl Surfactants on Surface Soils: Effect of Molecular Structures, Soil Properties, and Solution Chemistry.

Zwitterionic, cationic, and anionic per- and polyfluoroalkyl substances (PFASs) are identified in aqueous film-forming foam (AFFF) concentrates and AFFF-impacted sites. However, the mobility potential of zwitterionic and cationic PFASs is poorly understood, preventing reliable site assessment. The study aimed to elucidate the mobility behaviors of PFASs of various charge states in saturated soil-water systems and assess critical influencing factors. Five anionic, three zwitterionic, and one cationic PFASs were investigated in five soils through batch sorption experiments. Pairwise comparison revealed that the quaternary ammonium group imparted a strong affinity of cationic perfluorooctaneamide ammonium compound (PFOAAmS) for soils. The influence of the quaternary ammonium group is mitigated in polyfluoroalkyl betaines, yet perfluorooctane sulfonamidoalkyl betaine (PFOSB) showed strong sorption in selected soils. Two soil bulk properties showed some correlations with the soil-water distribution coefficient (Kd). A positive correlation with the fraction of soil organic carbon was found only for anionic PFASs, whereas cation exchange capacity had an approximate positive correlation with Kd only for PFOAAmS. Water chemistry (Ca2+ and pH) influences the sorption of nonanionic PFASs in very distinct fashions or even in opposite trends to what was known for anionic PFASs. Sorption was insensitive to pH changes except for PFOSB; PFOSB underwent profound sorption reduction because its speciation occurs around neutral pH, while the two other betaines and PFOAAmS have pKa values that are outside of the environmentally relevant range. The lack of correlations suggests that the transport potential of PFASs is probably highly site-specific. It remains a challenge in deciphering PFAS sorption mechanisms and predicting how AFFF plumes migrate.

Soil–air partitioning of volatile organic compounds into soils with high water content

Environmental contextAssessing environmental and human health impacts of chemical spills relies on information about how chemicals move across multiple environments. We measured volatile contaminants in the air above soil saturated with water to provide estimates of air concentrations of selected chemicals released to soil from an oil refinery in Texas during Hurricane Harvey. Estimated concentrations were below recommended exposure limits, even in a worst-case scenario. AbstractThe emission of volatile organic compounds (VOCs) from soil into air is affected by soil moisture dynamics, soil temperature, solar irradiance and carbon availability. The high amount of water in soil can modify its properties, which changes how VOCs interact. We conducted a comprehensive measurement of the soil–air partition coefficient (KSA) of VOCs into water-saturated soil with both low and high water contents for polar, weakly polar and nonpolar VOCs into a mineral soil (S-clay) and soil containing a high amount of organic matter (S-om) under a water-saturated condition. Partitioning of non-polar substituted aromatics (1,2-dichlorobenzene and toluene) was sensitive to the organic matter content in water-saturated soil. 1,2-Dichlorobenzene and toluene had higher affinities to S-om than to S-clay at all investigated water contents because of their strong interaction with the organic matter in soil. KSA decreased with elevated water content only for non-polar substituted aromatic VOCs. Less hydrophobic VOCs (benzene and trichloroethylene) exhibited similar partitioning into both soils by sorbing onto the air-water interface and dissolving in soil water, while the organic matter did not affect partitioning. The weakly polar and polar VOCs (methyl tert-butyl ether and 1-butanol) showed similar partitioning into both soils by dissolving in soil water while sorption to the organic matter was significant only at high soil water contents. KSA of VOCs on soil with high organic matter content correlated strongly with psat and Koa, but not on mineral soil. Estimates of the air concentrations for a subset of VOCs released from one refinery during Hurricane Harvey in 2017 in Harris County, Texas were lower than the recommended exposure limits, even under a worst-case scenario.

Experimental investigation of physical and mechanical properties of processes accompanied with phase transition in water-saturated soil

Nowadays, in view of increasing occurrence depth and complication of hydrogeological conditions in mineral deposits, the construction of vertical shafts is conducted using the artificial freezing technology. Therefore, mechanical processes mechanical behavior of water-saturated rock layers during freezing and thawing processes require a deep analysis.The paper considers the possibility of using a fiber-optic system for recording a temperature decrease during a soil freezing process and deformations arising in water-saturated soil due to frost heave. The features of the freezing front propagation and moisture redistribution are discussed. Two types of experiment were carried out all-round freezing and one-side freezing. It is important that the experiments simulate different direction of freezing front propagation. To analyze the experimental data a thermo-hydro-mechanical model is proposed. The model takes into account non-instantons kinetics of water crystallization, residual moisture content contained in the soil under temperature below the freezing temperature, moisture migration to the freezing front and an evolution of a stress-strain state of the soil caused by thermal strain and volumetric expansion due to the phase change of water into ice and the moisture flow. Results of the performed study have been shown that the numerical prediction of temperature change are in good agreement to the measurements, but there is qualitative difference between the frost heave deformation given by the model and registered by the sensors.

Water saturated foundation soil features

Water saturated foundation soil features

Effects of microplastics and earthworm burrows on soil macropore water flow within a laboratory soil column setup

AbstractSeveral earlier studies reported that microplastics (MP) accumulated on soil surfaces could be transported into the subsoil and ingested by soil biota, such as earthworms. The present study explores how networks of earthworm burrows and MP (low‐density polyethylene, LDPE) in subsoil affect the soil hydraulic properties and saturated water flow. A repacked and saturated sandy soil column experiment was conducted in an environment‐controlled laboratory with earthworms (anecic, Lumbricus terrestris) inoculated into the soil columns to form networks of macropore. The macropore network parameters (i.e., number, length, volume, diameter, soil saturated conductivity, and tracer breakthrough curves of soil columns) have been determined. The relative arrival times of the tracer mass (i.e. T5%, T25%, and T50%) were determined in order to describe the shapes of the breakthrough curves. The results show that in some breakthrough curves for the treatments with earthworms, there are two peaks. This is an indication that water was flowing faster in the macropores than in the soil matrix. There is a significant correlation between 5% arrival time and the median burrow volume, and the correlation coefficient was .571 (at the level of p < .05). The formation of macropores due to the burrowing activities of earthworms is considered the main cause of nonequilibrium water flow in the present study. The MP did not show any significant effect on the saturated water flow. This may be attribute to the low concentrations of MP used in the present study.

Possibility of using RIT technology in the ground conditions of Vietnam

The article compares engineering and geological conditions in the coastal areas of Vietnam and Tunisia. A sufficiently high similarity of soil structure and their physical and mechanical properties was noted. Both in Vietnam and in Tunisia, foundations for responsible buildings and structures are arranged on bored piles of the same length of 40-60 meters and a diameter of 600 to 1600 mm. The article provides examples of using super-piles of small-size RIT using recharge impulse technology in conditions of weak water-saturated coastal soils of Tunisia. The high efficiency and cost-effectiveness of the new recharge impulse technology were noted. The article presents photographic materials of the test stand for conducting field tests of piles, presents and analyzes the results of testing piles with vertical static load. The low precipitation of the tested piles and their high load-bearing capacity prove the promise of using super-piles of RIT in the conditions of weak soils of Tunisia and, consequently, in the coastal areas of Vietnam.

Semi-Empirical Method for evaluating Risk of Liquefaction during earthquakes a Study Case of Rhiss Dam

Liquefaction is a hazardous and temporary phenomenon by which water saturated soil loses some or all of its resistance. The undrained conditions linked to the cyclic load increase the pores water pressure inside the soil and consequently reduce effective stress. As a result, the soil can no longer resist or hold the shear forces, and lead to enormous deformations that directly influence the stability of structures and infrastructures foundations. Since 1964, several semi-empirical methods have been invented to evaluate the liquefaction potential using the in-situ test results. This study is based on the correlation between experimental data results of Menard pressuremeter and SPT dynamic penetrometer tests. Samples used in this test come from the Rhiss dam located in the North of Morocco, 24 kilometers as the crow flies from the town of Al Hoceima and south of the foundations of a calcareous ridge. The studied area have high seismic activity and a high percentage of fine soil elements, which suggests the possibility of soil liquefaction. We present and discuss the results of applying Idriss and Boulanger, and Youd et al methods in the evaluation of liquefaction susceptibility.

Numerical simulation of cement grouting of saturated soil during a mine shaft sinking using the artificial ground freezing

Cement grouting is widely applied in geotechnical engineering to reinforce water saturated soil and to control groundwater. The present paper is devoted to a numerical study of cement grout injection in a soil stratum during a construction of a vertical mine shaft using the artificial ground freezing (AGF) technology. For the study a thermo-hydro-mechanical model was developed. The governing equations of the model are derived based on the theory of porous media. The model takes into account the features of AGF and grouting processes such as a non-Newtonian behavior of cement grout flow, water-ice phase change and an influence of pore pressure and temperature on an evolution of a stress-strain of the soil. Three-dimensional numerical simulation of cement grouting of unfrozen soil between the shaft lining and the ice-soil wall was conducted using the model for various injection regimes. Results of the simulation have shown that the grout injection leads to a rise in temperature and volumetric strain in the soil. A mechanical impact of the injection procedure on the shaft lining is an increase in the mechanical pressure near the injection boreholes and a redistribution of the von Mises stress.

Elimination of Uneven Settlements During the Construction of Buildings in Complex Hydrogeological Conditions

The main factors influencing the occurrence of uneven settlement of buildings and structures are given. Since the existing methods of calculation of bases and foundations are not sufficient to ensure the guaranteed stability of buildings built on weak clay water-saturated soils, when designing it is necessary to assess the possibility of uneven settlements and provide ways to eliminate them at minimal cost. Based on the analysis of previously performed work on this issue and the conducted research, the designs of the foundation plate and the plate pile grillage are proposed, which make it possible to produce additional pressing or indentation of composite piles through holes in the plate when occurring a roll. The method of pressing composite piles using a support frame is described and the main measures that need to be carried out during the production of works are formulated. The use of the proposed method will reduce the cost of straightening the rolls by an order of magnitude and virtually eliminate the performance of these works at the stage of operation of the building.

Применение виброгрейфера для выполнения специальных видов строительных работ

Performing special types of construction work is accompanied by extraction of soil from the cavity of various structural elements immersed in the soil. The use of traditional jaw rope grabs for these purposes does not provide high productivity. The authors of the article consider the task of extracting water-saturated soils without large inclusions using vibrating grabs.

Effect of Deep Vibration on Water-Saturated Soil Consolidation

Effect of Deep Vibration on Water-Saturated Soil Consolidation