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Fictitious soil pile model for dynamic analysis of pipe piles under high-strain conditions

《结构与土木工程前沿（英文）》页码 915-934 doi: 10.1007/s11709-023-0907-8

摘要： A fictitious soil pile (FSP) model is developed to simulate the behavior of pipe piles with soil plugs undergoing high-strain dynamic impact loading. The developed model simulates the base soil with a fictitious hollow pile fully filled with a soil plug extending at a cone angle from the pile toe to the bedrock. The friction on the outside and inside of the pile walls is distinguished using different shaft models, and the propagation of stress waves in the base soil and soil plug is considered. The motions of the pile−soil system are solved by discretizing them into spring-mass model based on the finite difference method. Comparisons of the predictions of the proposed model and conventional numerical models, as well as measurements for pipe piles in field tests subjected to impact loading, validate the accuracy of the proposed model. A parametric analysis is conducted to illustrate the influence of the model parameters on the pile dynamic response. Finally, the effective length of the FSP is proposed to approximate the affected soil zone below the pipe pile toe, and some guidance is provided for the selection of the model parameters.

关键词： fictitious soil pile soil plug pipe piles high-strain dynamic analysis one-dimensional wave theory pile dynamics

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Design and analyses of open-ended pipe piles in cohesionless soils

Yuan GUO,Xiong (Bill) YU

《结构与土木工程前沿（英文）》 2016年第10卷第1期页码 22-29 doi: 10.1007/s11709-016-0314-5

摘要： Large open-ended pipe pile has been found to be advantageous for use in transportation projects. The current design method, however, is not adequately developed. To close this practice gap, this paper first summarized different design methods for open-ended pipe piles in sandy soils. A major factor for all the design codes is to properly account for the formation and effects of soil plug. The comparison indicates that there is a large variation in the base capacity evaluation among different methods due to the complex behaviors of soil plug. To close the knowledge gap, discrete element method (DEM) was used to simulate the soil plugging process and provide insight on the plugging mechanism. The simulation results show that the arching effect significantly increases the internal unit shear resistance along pipe piles. The porosity distribution and particle contact force distribution from DEM model indicate a large stress concentration occurs at the bottom of the soil plug. Besides, nearly 90% of the plug resistance is provided by the bottom half portion of the soil column. The soil-pile friction coefficient has a significant effect on the magnitude of plug resistance, with the major transition occurred for friction coefficient between 0.3 and 0.4.

关键词： open-ended pipe pile soil plug DEM base capacity

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Organic and inorganic phosphorus uptake by bacteria in a plug-flow microcosm

Jinbo ZHAO, Xuehua LIU

《环境科学与工程前沿（英文）》 2013年第7卷第2期页码 173-184 doi: 10.1007/s11783-013-0494-3

摘要： Phosphorus (P) is a vital nutrient for sustaining natural water productivity. Both particulate and dissolved forms of organic and inorganic P are potentially important sources of bioavailable P for primary and secondary producers. A microcosm system to imitate the bacterial community in Plym river sediment and pore water is described and bacterial uptake rates for inorganic and organic phosphorus are presented in this paper. The aim of this study was to investigate the uptake of two organic phosphorus compounds (phytic acid and D-glucose-6-phosphate) by freshwater bacteria. The bioreactors comprise glass columns packed with two types of small glass beads on which bacterial biofilm can develop. The glass beads with different porosity were introduced to simulate River SPM. The selected P compounds spiked into the inflow of the microcosm, and measured the step change of P concentration in the outflow to investigate the behavior of bacterial uptake of nutrients. The results showed that organic phosphorus was converted into inorganic phosphorus but the conversion rate depended on the type of phosphorus species. One experiment suggested that phytic acid (refractory) could displace phosphate from the biofilm surface; the other experiment showed that D-glucose-6-phosphate (labile) could be hydrolysed and utilized easily by the bacteria. The results also suggested that bacteria might break down the C-P bonds to utilize the carbon. Further experiments should investigate the effect of varying the C:N:P ratio in the microcosm system to determine which nutrient limits bacteria uptake.

关键词： organic phosphorus bacteria uptake

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Full lifetime cost analysis of battery, plug-in hybrid and FCEVs in China in the near future

Zhihua CAI, Xunmin OU, Qian ZHANG, Xiliang ZHANG

《能源前沿（英文）》 2012年第6卷第2期页码 107-111 doi: 10.1007/s11708-012-0182-1

摘要： This paper analyzes the full lifetime cost of battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and fuel cell electric vehicles (FCEVs) in China in the near future. The full lifetime cost comprises the initial and periodic cost of owning and operating the vehicle. Compared with the conventional gasoline vehicles, the full lifetime cost of the BEVs, PHEVs and FCEVs are approximately 1.5, 0.5 and 2.3 times more in the short term, respectively, due to the higher initial costs and higher non-energy-related costs though the fuel costs are lower. The results also suggest that with reasonably anticipatable technological progress in the long term, the lifetime cost of advanced electric vehicles (EVs) can be close to that of gasoline vehicles. It is found that two aspects of action are most important to make BEVs cost-effective: to support technology improvement to decrease the high cost of BEV and to formulate high energy cost of operating the conventional gasoline car. Moreover, it is important to decrease the non-energy operating costs including registration fee, tax rate and etc., of BEVs at the same time.

关键词： electric vehicle (EV) life time cost China

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state-of-charge trajectory estimation using upcoming route information preview and neural networks for plug-in

Ahmad MOZAFFARI,Mahyar VAJEDI,Nasser L. AZAD

《机械工程前沿（英文）》 2015年第10卷第2期页码 154-167 doi: 10.1007/s11465-015-0336-z

摘要：

The main proposition of the current investigation is to develop a computational intelligence-based framework which can be used for the real-time estimation of optimum battery state-of-charge (SOC) trajectory in plug-in hybrid electric vehicles (PHEVs). The estimated SOC trajectory can be then employed for an intelligent power management to significantly improve the fuel economy of the vehicle. The devised intelligent SOC trajectory builder takes advantage of the upcoming route information preview to achieve the lowest possible total cost of electricity and fossil fuel. To reduce the complexity of real-time optimization, the authors propose an immune system-based clustering approach which allows categorizing the route information into a predefined number of segments. The intelligent real-time optimizer is also inspired on the basis of interactions in biological immune systems, and is called artificial immune algorithm (AIA). The objective function of the optimizer is derived from a computationally efficient artificial neural network (ANN) which is trained by a database obtained from a high-fidelity model of the vehicle built in the Autonomie software. The simulation results demonstrate that the integration of immune inspired clustering tool, AIA and ANN, will result in a powerful framework which can generate a near global optimum SOC trajectory for the baseline vehicle, that is, the Toyota Prius PHEV. The outcomes of the current investigation prove that by taking advantage of intelligent approaches, it is possible to design a computationally efficient and powerful SOC trajectory builder for the intelligent power management of PHEVs.

关键词： trip information preview intelligent transportation state-of-charge trajectory builder immune systems artificial neural network

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Smart product design for automotive systems

A. Galip ULSOY

《机械工程前沿（英文）》 2019年第14卷第1期页码 102-112 doi: 10.1007/s11465-019-0527-0

摘要： Automobiles evolved from primarily mechanical to electro-mechanical, or mechatronic, vehicles. For example, carburetors have been replaced by fuel injection and air-fuel ratio control, leading to order of magnitude improvements in fuel economy and emissions. Mechatronic systems are pervasive in modern automobiles and represent a synergistic integration of mechanics, electronics and computer science. They are smart systems, whose design is more challenging than the separate design of their mechanical, electronic and computer/control components. In this review paper, two recent methods for the design of mechatronic components are summarized and their applications to problems in automotive control are highlighted. First, the combined design, or co-design, of a smart artifact and its controller is considered. It is shown that the combined design of an artifact and its controller can lead to improved performance compared to sequential design. The coupling between the artifact and controller design problems is quantified, and methods for co-design are presented. The control proxy function method, which provides ease of design as in the sequential approach and approximates the performance of the co-design approach, is highlighted with application to the design of a passive/active automotive suspension. Second, the design for component swapping modularity (CSM) of a distributed controller for a smart product is discussed. CSM is realized by employing distributed controllers residing in networked smart components, with bidirectional communication over the network. Approaches to CSM design are presented, as well as applications of the method to a variable-cam-timing engine, and to enable battery swapping in a plug-in hybrid electric vehicle.

关键词： mechatronics automotive control co-design component swapping modularity active suspensions variable camshaft timing engine plug-in hybrid electric vehicle

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Assessment of glass fiber-reinforced polyester pipe powder in soil improvement

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 742-753 doi: 10.1007/s11709-021-0732-x

摘要： This study investigates the use of glass fiber-reinforced polyester (GRP) pipe powder (PP) for improving the bearing capacity of sandy soils. After a series of direct share tests, the optimum PP addition for improving the bearing capacity of soils was found to be 12%. Then, using the optimum PP addition, the bearing capacity of the soil was estimated through a series of loading tests on a shallow foundation model placed in a test box. The bearing capacity of sandy soil was improved by up to 30.7%. The ratio of the depth of the PP-reinforced soil to the diameter of the foundation model (H/D) of 1.25 could sufficiently strengthen sandy soil when the optimum PP ratio was used. Microstructural analyses showed that the increase in the bearing capacity can be attributed to the chopped fibers in the PP and their multiaxial distribution in the soil. Besides improving the engineering properties of soils, using PP as an additive in soils would reduce the accumulation of the industrial waste, thus providing a twofold benefit.

关键词： shallow foundation sandy soil bearing capacity soil improvement pipe powder

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Electromagnetic induction mapping at varied soil moisture reveals field-scale soil textural patterns

Hiruy ABDU, David A. ROBINSON, Janis BOETTINGER, Scott B. JONES

《农业科学与工程前沿（英文）》 2017年第4卷第2期页码 135-145 doi: 10.15302/J-FASE-2017143

摘要： Knowledge of the spatial distribution of soil textural properties is important for determining soil moisture storage and soil hydraulic transport properties. Capturing field heterogeneity without exhaustive sampling and costly sample analysis is difficult. Our objective was to employ electromagnetic induction (EMI) mapping in low apparent electrical conductivity (EC ) soils at varying soil water contents to capture time invariant properties such as soil texture. Georeferenced EC measurements were taken using a ground conductivity meter on six different days where volumetric water content ( ) varied from 0.11 to 0.23. The 50 m × 50 m field included a subsurface gravelly patch in an otherwise homogeneous silt-loam alluvial soil. Ordinary block kriging predicted EC at unsampled areas to produce 1-m resolution maps. Temporal stability analysis was used to divide the field into three distinct EC regions. Subsequent ground-truthing confirmed the lowest conductivity region correlated with coarse textured soil parent materials associated with a former high-energy alluvial depositional area. Combining maps using temporal stability analysis gives the clearest image of the textural difference. These maps could be informative for modeling, experimental design, sensor placement and targeted zone management strategies in soil science, ecology, hydrology, and agricultural applications.

关键词： soil electrical conductivity soil texture mapping temporal stability analysis

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SOIL CARBON CHECK: A TOOL FOR MONITORING AND GUIDING SOIL CARBON SEQUESTRATION IN FARMER FIELDS

《农业科学与工程前沿（英文）》 2023年第10卷第2期页码 248-261 doi: 10.15302/J-FASE-2023499

摘要：

● Establishment of a rapid tool for monitoring soil carbon sequestration in farmer fields.

关键词： 4 per 1000 initiative carbon sequestration climate action farmer fields SDG13 soil organic carbon soil testing

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Adsorption behavior of antibiotic in soil environment: a critical review

Shiliang WANG,Hui WANG

《环境科学与工程前沿（英文）》 2015年第9卷第4期页码 565-574 doi: 10.1007/s11783-015-0801-2

摘要： Antibiotics are used widely in human and veterinary medicine, and are ubiquitous in environment matrices worldwide. Due to their consumption, excretion, and persistence, antibiotics are disseminated mostly via direct and indirect emissions such as excrements, sewage irrigation, and sludge compost and enter the soil and impact negatively the natural ecosystem of soil. Most antibiotics are amphiphilic or amphoteric and ionize. A non-polar core combined with polar functional moieties makes up numerous antibiotic molecules. Because of various molecule structures, physicochemical properties vary widely among antibiotic compounds. Sorption is an important process for the environment behaviors and fate of antibiotics in soil environment. The adsorption process has decisive role for the environmental behaviors and the ultimate fates of antibiotics in soil. Multiply physicochemical properties of antibiotics induce the large variations of their adsorption behaviors. In addition, factors of soil environment such as the pH, ionic strength, metal ions, and organic matter content also strongly impact the adsorption processes of antibiotics. Review about adsorption of antibiotics on soil can provide a fresh insight into understanding the antibiotic-soil interactions. Therefore, literatures about the adsorption mechanisms of antibiotics in soil environment and the effects of environment factors on adsorption behaviors of antibiotics in soil are reviewed and discussed systematically in this review.

关键词： adsorption antibiotics environment factors soil

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A simplified method for the determination of vertically loaded pile-soil interface parameters in layeredsoil based on FLAC

Jiu-jiang WU,Yan LI,Qian-gong CHENG,Hua WEN,Xin LIANG

《结构与土木工程前沿（英文）》 2016年第10卷第1期页码 103-111 doi: 10.1007/s11709-015-0328-4

摘要： The numerical analysis of pile-soil interaction commonly requires a lot of trial works to determine the interface parameters and the accuracy cannot be ensured normally. Considering this, this paper first conducts a sensitivity analysis to figure out the influence of interface parameters on the bearing behavior of a single pile in sand. Then, a simplified method for the determination of pile-soil interface parameters in layered soil is proposed based on the parameter studies. Finally, a filed loading test is used for the validation of the simplified method, and the calculated results agree well with the monitoring data. In general, the simplified method proposed in this paper works with higher accuracy and consumes less time compared with the traditional trial works, especially on the determinations of interfacial cohesive and interfacial friction angle.

关键词： determination of interface parameters pile-soil interaction FLAC^3D sensitivity analysis layered soil

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Soil-water interaction in unsaturated expansive soil slopes

ZHAN Liangtong

《结构与土木工程前沿（英文）》 2007年第1卷第2期页码 198-204 doi: 10.1007/s11709-007-0023-1

摘要： The intensive soil-water interaction in unsaturated expansive soil is one of the major reasons for slope failures. In this paper, the soil-water interaction is investigated with the full-scale field inspection of rainwater infiltration and comprehensive experiments, including wetting-induced softening tests, swelling, and shrinkage tests. It is demonstrated that the soil-water interaction induced by seasonal wetting-drying cycles is very complex, and it involves coupled effects among the changes in water content, suction, stress, deformation and shear strength. In addition, the abundant cracks in the expansive soil play an important role in the soil-water interaction. The cracks disintegrate the soil mass, and more importantly, provide easy pathways for rainfall infiltration. Infiltration of rainwater not only results in wetting-induced softening of the shallow unsaturated soil layers, but also leads to the increase of horizontal stress. The increase of horizontal stress may lead to a local passive failure. The seasonal wetting-drying cycles tend to result in a down-slope creeping of the shallow soil layer, which leads to progressive slope failure.

关键词： strength intensive soil-water comprehensive Infiltration wetting-induced softening

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Remediation of arsenic contaminated soil by sulfidated zero-valent iron

《环境科学与工程前沿（英文）》 2021年第15卷第5期 doi: 10.1007/s11783-020-1377-z

摘要：

• Sulfidation significantly enhanced As(V) immobilization in soil by zerovalent iron.

关键词： Soil As(V) Sulfidation Zero-valent iron Magnetic separation

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INTERCROPPING SUSTAINABLY INCREASES YIELDS AND SOIL FERTILITY

《农业科学与工程前沿（英文）》 2021年第8卷第4期页码 659-661 doi: 10.15302/J-FASE-2021418

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A review of soil nematodes as biological indicators for the assessment of soil health

Qiaofang LU, Tongtong LIU, Nanqi WANG, Zhechao DOU, Kunguang WANG, Yuanmei ZUO

《农业科学与工程前沿（英文）》 2020年第7卷第3期页码 275-281 doi: 10.15302/J-FASE-2020327

摘要：

Healthy soils are essential for sustainable agricultural development and soil health requires careful assessment with increasing societal concern over environmentally friendly agricultural development. Soil health is the capacity of soil to function within ecological boundaries to sustain productivity, maintain environmental quality, and promote plant and animal health. Physical, chemical and biological indicators are used to evaluate soil health; the biological indicators include microbes, protozoa and metazoa. Nematodes are the most abundant metazoa and they vary in their sensitivity to pollutants and environmental disturbance. Soil nematode communities are useful biological indicators of soil health, with community characteristics such as abundance, diversity, community structure and metabolic footprint all closely correlated with the soil environment. The community size, complexity and structure reflect the condition of the soil. Both free-living and plant-parasitic nematodes are effective ecological indicators, contributing to nutrient cycling and having important roles as primary, secondary and tertiary consumers in food webs. Tillage inversion, cropping patterns and nutrient management may have strong effects on soil nematodes, with changes in soil nematode communities reflecting soil disturbance. Some free-living nematodes serve as biological models to test soil condition in the laboratory and because of these advantages soil nematodes are increasingly being used as biological indicators of soil health.

关键词： biological indicators community characteristics soil health soil nematodes