Surrounding Soil Research Articles

Prediction of Stresses and Settlement for TBM Tunnel Surrounding Soil

In recent years, modern technology in the construction of tunnels using tunnel-boring machines (TBM) is implemented in the practice of civil engineering in large cities which significantly reduces the harmful effects of tunneling on the ground's surface. Construction of the tunnel becomes fundamental and the exploitation of underground space form part of the infrastructure to treat the growing problem of mass rapid transit in urban cities. The method of tunnel construction numerical modeling based on the finite element method is used to evaluate of the ground movement induce tunneling which is an essential matter to predict the settlement through construction and their effects on adjacent buildings. A method of surface settlement prediction is based on field data and results of construction phases numerical modeling. In this study, the prediction of the settlement caused by tunneling by simulation model using numerical method (FEM), with Mohr-Coulomb. This method involves determination of the following characteristics of displacement process: the distribution of displacements, the position of the point of the maximum settlement and the value of the maximum settlement, and strains in the trough. The developed method for calculation of the settlements and he behavior of stress a round tunnel calculates and analysis the settlement during tunnel construction and compared with natural soil through various stages of construction of the tunnel. The results show the behavior of stresses of the native soil and predication of surface settlement through stages of construction of tunnel using the tunnel boring machines(TBM).

Surveying the Sweetpotato Rhizosphere, Endophyte, and Surrounding Soil Microbiomes at Two North Carolina Farms Reveals Underpinnings of Sweetpotato Microbiome Community Assembly

Farmers grow sweetpotatoes worldwide and some sub-Saharan African and Asian diets include sweetpotato as a staple, yet the sweetpotato microbiome is conspicuously less studied relative to crops such as maize, soybean, and wheat. Studying sweetpotato microbiome ecology may reveal paths to engineer the microbiome to improve sweetpotato yield, and/or combat sweetpotato pests and diseases. We sampled sweetpotatoes and surrounding soil from two North Carolina farms. We took samples from sweetpotato fields under two different land management regimes, conventional and organic, and collected two sweetpotato cultivars, ‘Beauregard’ and ‘Covington’. By comparing small subunit rRNA gene amplicon sequence profiles from sweetpotato storage root skin, rhizosphere, and surrounding soil, we found the skin microbiome possessed the least composition heterogeneity among samples, lowest alpha-diversity, and was significantly nested by the rhizosphere in amplicon sequence variant (ASV) membership. Many ASVs were specific to a single field and/or only found in either the skin, rhizosphere, or surrounding soil. Notably, sweetpotato skin enriched for Planctomycetaceae in relative abundance at both farms. This study elucidates underpinnings of sweetpotato microbiome community assembly, quantifies microbiome composition variance within a single farm, and reveals microorganisms associated with sweetpotato skin that belong to common but uncultured soil phylotypes. [Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .

Impact of Newly Build Lead-Acid Battery Agglomeration Area on the Surrounding Soil Environment: A Study Based on the Spatial Characteristics of Heavy Metals

To determine whether the newly built lead-acid battery agglomeration area in a town in northern Zhejiang had an impact on the surrounding soil environment after seven years of operation, 76 samples of surface soil around the lead-acid battery concentration area were collected, and the contents of Hg, As, Cu, Zn, Pb, Cd, Ni, and Cr in the soil were determined. Based on the spatial distance of the agglomeration area and 50, 450, and 850 m from the agglomeration area boundary, the soil environmental quality was evaluated using the single factor index, Nemerow comprehensive pollution index, and potential ecological risk index methods. The spatial distribution characteristics of the heavy metals were analyzed using the geostatistical method, and the sources of heavy metals affecting the soil environment were determined by correlation analysis. The results showed that the average contents of Hg, Zn, and Pb in eight heavy metals were higher than their corresponding background values at all spatial scales. The average Cd content in spatial scales other than the agglomeration area was larger than its background value. Only As at 50 m was greater than its background value, whereas the average content of other elements at all spatial distances was lower than their corresponding background values. The spatial variability was high for Hg and Cd but not obvious for other elements. This implies that the influence of regional activities was concentrated mainly on Hg and Cd; the content of both increased with distance from the agglomeration area. Hg and Cd exceeded the risk screening values and were distributed mainly at 450 m and 850 m; 33.33% and 38.89% Hg points and 27.78% and 55.56% Cd points were observed at these distances, respectively. The spatial distribution characteristics of Hg and Cd were consistent with their contents; only Zn and Pb had scattered points that exceeded the risk screening values and generally no obvious spatial distribution characteristics. According to the risk analysis of soil comprehensive pollution caused by the eight heavy metals, Cd was the main source of soil comprehensive pollution risk at a contribution rate of 36.73%, which caused the soil at 850 m to be in a state of alert. Soil ecological risk at a medium level occurred mainly at 450 m and 850 m outside the agglomeration area from Hg and Cd. The contribution rates to the soil quality at these distances were 46.30% and 39.37% for Hg and 38.98% and 49.30% for Cd, respectively. This indicates that regional activities caused Hg and Cd to be the main elements affecting soil quality in the study area. The results of geostatistics and multivariate statistical analysis showed that Hg and Cd were diffused inward from the periphery of the agglomeration area on the axis of the local main wind direction (northeast-southwest), and the main sources of both were coal-burning activities of enterprises in the periphery of the agglomeration area. In summary, the newly build lead-acid battery agglomeration area has not significantly affected the accumulation of heavy metals in the agglomeration area and in the surrounding soil after seven years of operation.

Interaction of Gravel Piles with the Surrounding Soil and Raft

This paper provides a quantitative assessment of the stress-strain state of the "crushed stone pile−surrounding compacted soil−grillage" (cell) system under static and variable loads, taking into account the elastic and elastic-viscous properties of the pile and the surrounding soil. The potential for defining the parameters for deformability and viscosity of the cell, required for carrying out simplified calculations for the foundation known as "piles under the slab," is illustrated. The influence of the pile on the dynamic properties of the base (without piles), including the dynamic response factor, dependent on the frequency of the natural oscillations of the cell, with and without the influence of the pile, is evaluated.

Erratum for “Effect of Open-Ended PHC Pile Installation during Embankment Widening on the Surrounding Soil” by Guowei Li, Andrew Cudzo Amenuvor, Yuzhou Hou, Xiaocen Lu, Jiantao Wu, and Thang Ngoc Nguyen

Erratum for “Effect of Open-Ended PHC Pile Installation during Embankment Widening on the Surrounding Soil” by Guowei Li, Andrew Cudzo Amenuvor, Yuzhou Hou, Xiaocen Lu, Jiantao Wu, and Thang Ngoc Nguyen

Measurement of Radioactivity Levels and Health Risks in the Surrounding Soil of Shazand Refinery Complex in Arak, Iran, Using Gamma-Ray Spectrometry Method

ntroduction: The purpose of this study was to measure the radioactivity in the agricultural soil of south-east of Shazand Refinery Complex to determine both reliable baseline data on the radiation level and the radiation dose exposure to the farmers and inhabitants of the studied area. Material and Methods: This study was conducted on 21 soil samples collected from two different lands. Sampling spots in each land were selected for the assessment of specific activities of radionuclides of 226Ra, 232Th, 40K, and137Cs by using high purity germanium detector setup. Standards of International Atomic Energy Agency references material gamma ray uranium, reference gamma-ray thorium, and reference gamma-ray potassium were used for quality control and determining efficiency calibration. All samples were examined for radium equivalent, absorbed gamma dose rate, internal hazard index, external radiation hazard, annual gonadal dose equivalent, indoor and outdoor annual effective dose equivalent, and excess lifetime cancer risk. Results: The specific activities of radionuclides 226Ra, 232Th, 40K, and 137Cs varied from13.12 to 33.03, 11.3 to 35.86, 257.82 to 605.5, and 1.28 to 13.36 Bq/kg, respectively. Moreover, the results of this study were compared with those reported from other countries and worldwide average. Conclusion: Although all samples were polluted by the 137Cs fission product, the measured values were within the global reported safety limits. Therefore, there is no risk for farmers and inhabitants in this region.

Deformation Analysis of a Geosynthetic-Encased Stone Column and Surrounding Soil Using Cavity-Expansion Model

Deformation Analysis of a Geosynthetic-Encased Stone Column and Surrounding Soil Using Cavity-Expansion Model

Influence Analysis of Underground Excavation on the Adjacent Buildings and Surrounding Soil Based on Scale Model Test

In urban areas, it is common to construct underground structure nearby existing buildings. To investigate the impact of excavation construction on the adjacent existing buildings and surrounding soil, eight parallel scale model tests that considered the process of cut and cover construction are carried out with two kinds of the diameter of support piles, two kinds of the adjacent structure, and two kinds of the relative horizontal distance from the excavation in the laboratory. And, the variations of horizontal and vertical displacements of adjacent buildings and the soil pressure surrounding the excavation and the foundations of existing buildings with different parameters are presented and discussed. Then, the experimental data and the results of eight prototype finite element models are compared and analyzed.

Effect of Open-Ended PHC Pile Installation during Embankment Widening on the Surrounding Soil

AbstractThis paper investigates the effect of jacking two groups of open-ended prestressed high-strength concrete (PHC) piles on an existing highway embankment based on field measurements of excess...

Vibration Characteristics of Underground Structure and Surrounding Soil Underneath High Speed Railway Based on Field Vibration Tests

A series of field vibration tests were carried out at an underground metro station underneath the high speed railway by installing accelerometers both on the side wall of the metro station and in the surrounding soil. Within the frequency domain of 0–200 Hz, the attenuation, transmission, and frequency response properties of vibration for both the underground structure and the surrounding soil were analyzed and compared. The attenuation index is found to be decreased with the increase of underground structure stiffness. The existence of damping and coupling effect of the surrounding soil, as well as the interference of axle spectrum from excitation sources, makes it very challenging to separate the frequency response characteristics of structures from soil at FFT (Fast Fourier Transform) spectrum. The combined NExT (Natural Excitation Technique) and HHT (Hilbert–Huang Transform) method are thus used to study the waveforms and propagation velocities of vibration waves in underground structure and surrounding soil. The wave types and their speeds are determined and used for evaluating the structural elastic modulus. Compared with the attenuation index or natural frequency, wave velocity is easier to be recognized, is sensitive to the change of the structural stiffness, and requires limited number of sensors in the field. Based on the properties of the vibration characteristics studied in this work, the wave velocity based method is recommended for the health monitoring of underground structures.

Influence of Surrounding Soil Conditions and Joint Sealing on Seepage Resistance of a Sheet Pile Wall, Three Dimensional Numerical Analyses

The aim of this article is to present 3D numerical calculations results of the seepage resistance of sheet pile (SP) wall with sealed joints. In the present work the leakage through SP wall was determined for one joint of full length. In the analysed example, the SP wall passed through one kind of soil but some conditions (permeability of joint and of surrounding soil) changed depending on the adopted assumptions.To find the distribution of the total head in the calculation area Laplace equation was used. To determine the velocity field Darcy's law was adopted.In the first step, the discharge flowing through the single joint of SP wall based on 3D numerical simulations was determined. In the next step, the joint resistance was estimated and the discharge was found analytically. The results obtained using these two methods were compared. And the conclusions are as follows: it seems possible to estimate the „joint permeability” coefficient using numerical methods, in some conditions the analytical results are far away from numerical ones, due to the nonlinear pressure distribution along the joint, it is necessary to collect in-situ data to confirm the usefulness and reliability of obtained solutions and to proposed more complete methods of determination of SP wall seepage resistance.

Effect of Cement Factory Exhaust on Radiological Contents of Surrounding Soil Samples in Assuit Province, Egypt

Effect of Cement Factory Exhaust on Radiological Contents of Surrounding Soil Samples in Assuit Province, Egypt

Determination of Total Chromium and Chromium Species in Kombolcha Tannery Wastewater, Surrounding Soil, and Lettuce Plant Samples, South Wollo, Ethiopia

This research paper deals with the determination of total chromium (total Cr), Cr(III), and Cr(VI) in Kombolcha leather industrial wastewater and the surrounding (soil and lettuce plant) samples where the wastewater flows. The levels of total Cr, Cr(VI), and Cr(III) in wastewater, soil, and lettuce plant samples were determined by FAAS, UV/Vis spectrophotometer, and difference (Cr(VI) from total Cr), respectively. Among all samples taken, the maximum amounts of total Cr, Cr(III), and Cr(VI) were obtained at the discharging point and the minimum amounts of total Cr and Cr(III) were found downstream (400 m from the junction) of Kombolcha leather industrial wastewater. On the other hand, the minimum concentration of Cr(VI) was obtained in lettuce plant sample. The amounts of total Cr in all samples except soil sample were above the permissible limit as set by WHO/FAO. The concentrations of Cr(III) in all wastewater samples were above the permissible level, whereas the concentration of Cr(VI) in wastewater was above the permissible level except 400 m from the junction. The result showed that a remarkable elimination of total Cr and Cr species has not been achieved by this leather industry as its level was not much decreased when entered into the water systems. Therefore, effective treatment methods should be applied to the wastewater for the wellbeing of the surroundings.

Dynamic torsional response of an elastic pile in a radially inhomogeneous soil

Surrounding soil may be weakened or strengthened due to construction disturbance of the pile, resulting in soil properties varying gradually in the radial direction. In this paper, an analytical solution is developed to investigate the torsional vibration of an elastic pile embedded in a radially inhomogeneous soil and subjected to a time-harmonic torsional loading. The radially inhomogeneous soil is subdivided into many thin concentric annular sub-zones, with each having constant complex shear modulus in radial direction. The dynamic equilibrium equation of each sub-zone of the soil is then solved and the circumferential displacement and shear stress along the pile-soil interface are obtained by a newly developed method that enforces the continuity conditions between the two adjacent sub-zones. By virtue of the boundary and continuity conditions of the pile-soil system, the torsional impedance at the pile head is derived in an exact closed form in the frequency domain. Some numerical results are presented to study the influence of the soil layer rigidities on the vibration characteristic of the pile-soil system.

Исследование взаимодействия асбестоцементных трубопроводов с окружающим грунтом

Исследование взаимодействия асбестоцементных трубопроводов с окружающим грунтом

Experimental Study on Evolution Characteristics of the Heat Storage of Surrounding Soil in Subway Tunnels

The evolution characteristics of the heat reservoir of surrounding rock in subway tunnels have been analyzed by a scaled model experimental test for 17 years from new to long-term operation with periodic and dynamic air temperature conditions. According to its variation characteristics with time, soil temperature distribution with time is divided into the dynamic expanding period and the dynamic stable period. The evolution characteristics of soil temperature is varied with depth and the heat storage and release are pointed out. It has been found that the soil heat reservoir thickness is 20m with the peak temperature of the soil heat reservoir 22.7℃ and the soil heat reservoir characteristic thickness 2m. All of these works provides references to solve the tunnel temperature problems in long-term subway operation.

The Impact of Cassava Wastewater from Starch Processing Industry on Surrounding Soil: A Case Study of Matna Foods Industry, Ogbese

This study is aimed at determining the impacts of indiscriminate disposal of processed cassava wastewater into the environment by determining the physicochemical characteristics of the wastewater and soil characteristics within the vicinity of starch processing industry.The cassava wastewaterquality wastested in accordance with the standard methods for the examination of water and wastewater while soil samples was analysed using Atomic Absorption Spectrometer. The result of cassava wastewatershows that the effluent is acidic with pH of 3.8 and high conductivity of 6500µΩ. The cyanide content is also very high with 0.17mg/l as compared to 0.05mg/l recommended by WHO. The total solid, total dissolved solid and total suspended solid are also in high range of 20619, 17048 and 3571 mg/l respectively. Its hardness is 812mg/l, chloride 2516mg/l and nitrate 470mg/l. The dissolved oxygen was not detected while COD and BOD were also on the high side with values of 560 and 1410mg/l respectively. The results of soil analysis indicates that the cyanide concentration is high at the surface but reduces with depth. The pH is also in acidic range. However, Magnesium, Sodium, Sulphate, Zinc, Chromium, Vanadium, Europium and Rubidium were not detected in the soil samples. The percentage of calcium, potassium, copper, manganese and titanium were small and varying between 0.07 and 6.37ppm. Three unlined aerobic ponds provided for the treatment of cassava wastewater reduces the pollution strength of the wastewater but the untreated wastewater interfere with the surrounding soil during conveyance to the pond as well as pond environment.It is recommended that the wastewater conveyance and ponds should be well designed to prevent interference with the surrounding soil.

Closure to “Interaction between Laterally Loaded Pile and Surrounding Soil” by Hai Lin, Lusu Ni, Muhannad T. Suleiman, and Anne Raich

Closure to “Interaction between Laterally Loaded Pile and Surrounding Soil” by Hai Lin, Lusu Ni, Muhannad T. Suleiman, and Anne Raich

Interaction of Compaction Piles with Surrounding Soil with Due Regard for Pile Diameter Expansion

Analytical and numerical solutions are provided for the problem of the interaction between compaction piles and a foundation slab and a surrounding soil cylinder that rests on an incompressible bed, with due regard for the potential expansion of the pile shaft. Closed solutions are obtained for determining stresses in the pile shaft and the soil under a foundation slab in an end bearing pile scheme. This issue is most immediate for transforming beds using drain piles composed of a sand-gravel mixture.

Influence of Pipe Ramming on Stress State of Surrounding Soil and Nearby Tunnel Lining

ANNOTATIONThis article proposes an approach to the prediction of stress state and assessing the strength of a circular tunnel lining and the surrounding rock mass under construction near the production used by the micro-tunneling technology of pipe ramming. The basis of this method is an analytical solution of the corresponding plane problem of elasticity theory.