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Monitoring of cable stayed bridge during service is the key to ensure the safety of the bridge. To improve the monitoring technologies, this paper summarized the relevant research and application, including Stay cable monitoring, tower column monitoring. The results show that the method of monitoring has changed from manual to machine. The principles of monitoring are more abundant, such as image analysis, acceleration analysis, magnetic flux analysis, temperature analysis and so on. This paper can provide reference for the further research on the monitoring technology of cable-stayed bridge.
Jiabao Du; Zhao Hong; Yuan Chen; Yahui Li; Jinzhu Song; Qiang Tang. Research on Monitoring Technology of Cable-Stayed Bridge. Lecture Notes in Civil Engineering 2021, 69 -75.
AMA StyleJiabao Du, Zhao Hong, Yuan Chen, Yahui Li, Jinzhu Song, Qiang Tang. Research on Monitoring Technology of Cable-Stayed Bridge. Lecture Notes in Civil Engineering. 2021; ():69-75.
Chicago/Turabian StyleJiabao Du; Zhao Hong; Yuan Chen; Yahui Li; Jinzhu Song; Qiang Tang. 2021. "Research on Monitoring Technology of Cable-Stayed Bridge." Lecture Notes in Civil Engineering , no. : 69-75.
Both developing and developed countries are facing a series of difficulties and challenges in the process of urbanization. In recent years, in order to alleviate the problem of urban congestion, underground space has developed rapidly, and the excavation of foundation pit is the most important step in the development of underground space. This paper takes the foundation pit of the tunnel under construction in Suzhou as a research object. The design width of the foundation pit reaches 61.5 m and the depth reaches 18 m, so it belongs to the super wide and deep foundation pit. Numerical analysis is performed by finite element software to calculate the deformation of the foundation pit. The research shows that the main problem to be solved is the deformation of the foundation pit, and the deformation of side wall of foundation pit tunnel is the most obvious. The maximum deformation of the side wall of the main tunnel and the auxiliary tunnel reached the maximum at 15 m. The maximum deformation of the main tunnel is about 1.3 cm, and that of the auxiliary tunnel is about 0.9 cm. Through targeted design and construction, the mechanical performance of the foundation pit retaining structure is optimized, and the stability of the foundation pit is strengthened. The reasonable retaining structure can ensure the good construction quality. The design and construction of the project can provide reference for related engineering construction.
Shi Shenjie; Tian Angran; Zheng Yongsheng; Yin Peng; Qi Weilin; Tang Qiang. Design, construction and analysis for super-wide, deep and large foundation pit. Transport and Communications Science Journal 2021, 72, 117 -126.
AMA StyleShi Shenjie, Tian Angran, Zheng Yongsheng, Yin Peng, Qi Weilin, Tang Qiang. Design, construction and analysis for super-wide, deep and large foundation pit. Transport and Communications Science Journal. 2021; 72 (1):117-126.
Chicago/Turabian StyleShi Shenjie; Tian Angran; Zheng Yongsheng; Yin Peng; Qi Weilin; Tang Qiang. 2021. "Design, construction and analysis for super-wide, deep and large foundation pit." Transport and Communications Science Journal 72, no. 1: 117-126.
Greenhouse gas emission has been a serious problem for decades. Due to the high energy consumption of traditional construction and building materials, recycled aggregate and other environmentally-friendly materials or recycled materials have been researched and applied. The treatment and reuse of construction and demolition waste (CDW) is a good way to reasonably distribute the renewable resources in the urban city. The recycled aggregate can be used in road engineering, geotechnical engineering and structural engineering. The combined use of natural aggregate and recycled aggregate may possess better performance in real constructions. This paper investigates the mechanical performance, micro-mechanism and CO2 footprint assessment of NAM (natural aggregate mortar) and RAM (recycled aggregate mortar). Compressive strength test, flexural strength test, XRD and SEM, and CO2 emission evaluation were conducted and analyzed. The results indicate that NAM depicts better compressive strength performance and RAM has higher flexural strength. The XRD and SEM patterns illustrate that the ettringite and C-S-H are the most important role in shrinkage-compensating mechanism, which is more obvious in RAM specimens. The proportion of CaO and MgO hydrated into Ca(OH)2 and Mg(OH)2 is also a key point of the volume expansion through the curing period. Finally, the CO2 emission of NA is higher than RA per unit. This indicates that utilizing recycled aggregate over other conventional resources will reduce the energy consumption, and hit the mark to be environmental-friendly.
Junfang Sun; Ji Chen; Xin Liao; Angran Tian; Jinxu Hao; Yuchen Wang; Qiang Tang. The Workability and Crack Resistance of Natural and Recycled Aggregate Mortar Based on Expansion Agent through an Environmental Study. Sustainability 2021, 13, 491 .
AMA StyleJunfang Sun, Ji Chen, Xin Liao, Angran Tian, Jinxu Hao, Yuchen Wang, Qiang Tang. The Workability and Crack Resistance of Natural and Recycled Aggregate Mortar Based on Expansion Agent through an Environmental Study. Sustainability. 2021; 13 (2):491.
Chicago/Turabian StyleJunfang Sun; Ji Chen; Xin Liao; Angran Tian; Jinxu Hao; Yuchen Wang; Qiang Tang. 2021. "The Workability and Crack Resistance of Natural and Recycled Aggregate Mortar Based on Expansion Agent through an Environmental Study." Sustainability 13, no. 2: 491.
Carbon emission is one of the main causes of global climate change, thus it is necessary to choose a low-carbon method in the contaminated soil remediation. This paper studies the adsorption ability of ZVI on Pb(II) contaminated soils under different working conditions. The removal efficiency of Pb(II) was 98% because of the suitable ZVI dosage, log reaction time and low initial solution concentration. The whole balancing process was much fast according to the pseudo-second-order kinetic and Freundlich isothermal model. Moreover, sequential extraction procedure (SEP) showed Pb(II) was transformed from Fe/Mn oxides-bound form to residual form in Pb(II) contaminated soils. From scanning electron microscopy (SEM), Brunauer-Emmett-Teller method (BET) and X-ray diffraction (XRD) results, it was confirmed that zero-valent iron (ZVI) stabilizes Pb(II) pollutants mostly through the combination of chemical adsorption and physical adsorption. The economic and carbon emission assessments were used to compare the cost and carbon emissions of different methods. The results show that ZVI adsorption has excellent economic benefits and low carbon emission.
Junfang Sun; Angran Tian; Zheyuan Feng; Yu Zhang; Feiyang Jiang; Qiang Tang. Evaluation of Zero-Valent Iron for Pb(II) Contaminated Soil Remediation: From the Analysis of Experimental Mechanism Hybird with Carbon Emission Assessment. Sustainability 2021, 13, 452 .
AMA StyleJunfang Sun, Angran Tian, Zheyuan Feng, Yu Zhang, Feiyang Jiang, Qiang Tang. Evaluation of Zero-Valent Iron for Pb(II) Contaminated Soil Remediation: From the Analysis of Experimental Mechanism Hybird with Carbon Emission Assessment. Sustainability. 2021; 13 (2):452.
Chicago/Turabian StyleJunfang Sun; Angran Tian; Zheyuan Feng; Yu Zhang; Feiyang Jiang; Qiang Tang. 2021. "Evaluation of Zero-Valent Iron for Pb(II) Contaminated Soil Remediation: From the Analysis of Experimental Mechanism Hybird with Carbon Emission Assessment." Sustainability 13, no. 2: 452.
Immersed tunnels are generally connected by tube elements through the joints, which are the weakest parts and sensitive to deformation. However, it is inevitable that there will be vertical differential settlement between the joints of the tube element, resulting from uneven loads caused by back silting, differential settlement of foundations in soft soil, the heavy deposit of ground soil, and increasing tube length. Differential settlement at joints is very harmful to the safety of tunnel construction and operation, but the elastic foundation beam method—which is now widely used for calculation of settlement for immersed tunnels—cannot take joint differential settlement into account. Therefore, this paper proposes a new mechanical model for joints of immersed tunnels in consideration of the influence of joint differential settlement. The model is not only convenient for adoption in calculation, but also considers the influence of variation on the rigidity of groundwork. The results show that the bending stiffness of the joint changes with variations in differential settlement, and depends on whether differential settlement and the eccentricity are on the same side of the neutral axis or the other. Then, both the increase of eccentricity and the use of shear key will expose positive effect on the rise of bending stiffness. By calculating this mechanical model via considering differential settlement, the max error was only 7.3%. Therefore, it may have significance as safety guidelines for the construction and operation of immersed tunnels.
Peng Liu; Ji Chen; Yanhong Chen; Jianxin Yang; Qiang Tang. Mechanical Model for Joints of Immersed Tunnel Considering the Influence of Joint Differential Settlement. International Journal of Geosynthetics and Ground Engineering 2020, 6, 1 -10.
AMA StylePeng Liu, Ji Chen, Yanhong Chen, Jianxin Yang, Qiang Tang. Mechanical Model for Joints of Immersed Tunnel Considering the Influence of Joint Differential Settlement. International Journal of Geosynthetics and Ground Engineering. 2020; 6 (4):1-10.
Chicago/Turabian StylePeng Liu; Ji Chen; Yanhong Chen; Jianxin Yang; Qiang Tang. 2020. "Mechanical Model for Joints of Immersed Tunnel Considering the Influence of Joint Differential Settlement." International Journal of Geosynthetics and Ground Engineering 6, no. 4: 1-10.
Bioremediation using microorganisms is a promising technique to remediate soil contaminated with heavy metals. In this study, Sporosarcina pasteurii (S. pasteurii) bioremediation by mixing method was used to remediate soils contaminated with lead (Pb), zinc (Zn) and cadmium (Cd). A significant reduction of heavy metal leaching concentrations was observed in S. pasteurii bio-treated samples. Furthermore, urease hydrolyzing bacteria have additional advantages of accelerating metal precipitation by increasing pH. The soluble-exchangeable Pb, Zn and Cd was reduced by 33.3 % ∼ 85.9 %, 21.4 % ∼ 66.0 %, 13.6 % ∼ 29.9 % respectively after bioremediation. The primary objective of metal stabilization was achieved by reducing the bioavailability through immobilizing the Pb, Zn and Cd in the urease-driven carbonate precipitation. Luminescent bacteria toxicity experiments revealed that the metal toxicity of contaminated soil was reduced after bioremediation using S. pasteurii. When subjected to severe environmental conditions, S. pasteurii bioremediation was superior to chemical precipitation technology in terms of long-term stability.
Peng Liu; Yu Zhang; Qiang Tang; Shenjie Shi. Bioremediation of metal-contaminated soils by microbially-induced carbonate precipitation and its effects on ecotoxicity and long-term stability. Biochemical Engineering Journal 2020, 166, 107856 .
AMA StylePeng Liu, Yu Zhang, Qiang Tang, Shenjie Shi. Bioremediation of metal-contaminated soils by microbially-induced carbonate precipitation and its effects on ecotoxicity and long-term stability. Biochemical Engineering Journal. 2020; 166 ():107856.
Chicago/Turabian StylePeng Liu; Yu Zhang; Qiang Tang; Shenjie Shi. 2020. "Bioremediation of metal-contaminated soils by microbially-induced carbonate precipitation and its effects on ecotoxicity and long-term stability." Biochemical Engineering Journal 166, no. : 107856.
The treatment of contaminated soil is a crucial issue in geotechnical and environmental engineering. This study proposes to incorporate appropriate polypropylene fibers and cements as an effective method to treat heavy metal contaminated soil (HMCS). The objective of this paper is to investigate the effects of fiber content, fiber length, cement content, curing time, heavy metal types and concentration on the mechanical properties of soils. To this end, a series of direct shear test, unconfined compression strength (UCS) test, dry-wet cycle and freeze-thaw cycle test are performed. The results confirm that the appropriate reinforcement of polypropylene fibers and cement is an effective way to recycle HMCS as substitutable fillers in roadbed, which exhibits benefits in environment and economy development.
Yu-Cheng Huang; Ji Chen; Ang-Ran Tian; Hui-Long Wu; Yu-Qing Zhang; Qiang Tang. Mechanical properties of fiber and cement reinforced heavy metal-contaminated soils as roadbed filling. Journal of Central South University 2020, 27, 2003 -2016.
AMA StyleYu-Cheng Huang, Ji Chen, Ang-Ran Tian, Hui-Long Wu, Yu-Qing Zhang, Qiang Tang. Mechanical properties of fiber and cement reinforced heavy metal-contaminated soils as roadbed filling. Journal of Central South University. 2020; 27 (7):2003-2016.
Chicago/Turabian StyleYu-Cheng Huang; Ji Chen; Ang-Ran Tian; Hui-Long Wu; Yu-Qing Zhang; Qiang Tang. 2020. "Mechanical properties of fiber and cement reinforced heavy metal-contaminated soils as roadbed filling." Journal of Central South University 27, no. 7: 2003-2016.
A modified theoretical model has been proposed to predict the pore size characteristics of nonwoven geotextiles under certain uniaxial tensile strains, considering the difference between the out-of-plane Poisson’s ratio and the in-plane Poisson’s ratio of geotextiles. The pore size distributions (PSDs) and O95 subjected to different levels of uniaxial tensile strains in two needle-punched nonwoven geotextiles have been investigated by the dry sieving test. The variation of the fibre orientation with tensile strains and the corresponding effect on pore sizes has been evaluated by image analysis. The out-of-plane Poisson’s ratio and the in-plane Poisson’s ratio of geotextiles have been examined. A comparison has been made between the predictions of the original and the modified models. It is shown that the modified model can more accurately predict the decreasing rate of the PSDs, O95, and O98 than the original one. The corrected theoretical O95 and O98 under certain strains can provide a reference for the filtration design under engineering strains. The fibres reorientating to the loading direction result in the increase of the directional parameter with increasing tensile strains, which leads to the decrease of pore sizes. The theoretical PSDs are sensitive to the variation of directional parameter.
Lin Tang; Qiang Tang; Aolai Zhong; Hanjie Li. Prediction of Pore Size Characteristics of Needle-Punched Nonwoven Geotextiles Subjected to Uniaxial Tensile Strains. Advances in Civil Engineering 2020, 2020, 1 -12.
AMA StyleLin Tang, Qiang Tang, Aolai Zhong, Hanjie Li. Prediction of Pore Size Characteristics of Needle-Punched Nonwoven Geotextiles Subjected to Uniaxial Tensile Strains. Advances in Civil Engineering. 2020; 2020 ():1-12.
Chicago/Turabian StyleLin Tang; Qiang Tang; Aolai Zhong; Hanjie Li. 2020. "Prediction of Pore Size Characteristics of Needle-Punched Nonwoven Geotextiles Subjected to Uniaxial Tensile Strains." Advances in Civil Engineering 2020, no. : 1-12.
The further development of land reclamation, port waterway, and wharf construction brings about proper treatments of dredger fill silt, while huge amounts of rice straw set aside in China argument rational disposal every year. Therefore, rice straw is bundled up as ropes, which represent as drainage body and reinforcement, to make eco-friendly treatment for dredger fill silt. This paper investigates the mechanical properties and validity of rice straw rope as certain treating material of dredger fill silt through a series of pull-out test, mass loss test, and tension test on specimens with different water contents and dry densities. The results reveal that peak value of interfacial shear strength rises with the increase of normal stress at the same immersion time, and in particular, it rises by up to 250.0% when the normal stress is 40 kPa. The tensile force of rice straw rope increases slowly with the rise of tensile displacement, and the failure mode changes from brittle to ductile with the rise of immersion time, which witnesses first rapid back slow degradation trend. The proper interfacial shear strength, tensile force, and reasonable degradation rate of rice straw rope make it ideal in drainage and consolidation of dredger fill silt.
Guizhong Xu; Ji Chen; Shenjie Shi; Angran Tian; Qiang Tang. Shear Behaviors of the Intersurface between Rice Straw Rope and Dredger Fill Silt: Experimental and Mechanism Studies. Advances in Civil Engineering 2020, 2020, 1 -10.
AMA StyleGuizhong Xu, Ji Chen, Shenjie Shi, Angran Tian, Qiang Tang. Shear Behaviors of the Intersurface between Rice Straw Rope and Dredger Fill Silt: Experimental and Mechanism Studies. Advances in Civil Engineering. 2020; 2020 ():1-10.
Chicago/Turabian StyleGuizhong Xu; Ji Chen; Shenjie Shi; Angran Tian; Qiang Tang. 2020. "Shear Behaviors of the Intersurface between Rice Straw Rope and Dredger Fill Silt: Experimental and Mechanism Studies." Advances in Civil Engineering 2020, no. : 1-10.
The rapid development of industrialization, urbanization, and population of the society augments the rising amount of municipal solid waste (MSW). With the advantage of considerably reducing mass and volume of solid wastes and generating energy, the incineration is a widely used treatment method for MSW. During the incineration process, the organic substances contained in the wastes are combusted, and the massive residues are remained. Of the incineration residues, bottom ash takes up to 80–90%, and the remainders are fly ash along with air pollution control residues. Dealing with the municipal solid waste incineration (MSWI) bottom ash in a sustainable manner is the primary principle. Significantly, MSWI bottom ash has been successfully utilized in diverse beneficial applications in recent decades, especially in civil engineering applications. This paper investigates the mechanical properties and validity of MSWI bottom ash as applicable substitutes of conventional subgrade materials. For this reason, a series of direct shear and CBR tests are performed on specimens with different water contents and dry densities.
Yucheng Huang; Ji Chen; Shenjie Shi; Bin Li; Jialin Mo; Qiang Tang. Mechanical Properties of Municipal Solid Waste Incinerator (MSWI) Bottom Ash as Alternatives of Subgrade Materials. Advances in Civil Engineering 2020, 2020, 1 -11.
AMA StyleYucheng Huang, Ji Chen, Shenjie Shi, Bin Li, Jialin Mo, Qiang Tang. Mechanical Properties of Municipal Solid Waste Incinerator (MSWI) Bottom Ash as Alternatives of Subgrade Materials. Advances in Civil Engineering. 2020; 2020 ():1-11.
Chicago/Turabian StyleYucheng Huang; Ji Chen; Shenjie Shi; Bin Li; Jialin Mo; Qiang Tang. 2020. "Mechanical Properties of Municipal Solid Waste Incinerator (MSWI) Bottom Ash as Alternatives of Subgrade Materials." Advances in Civil Engineering 2020, no. : 1-11.
Xue Luo; Robert L. Lytton; Yuqing Zhang; Fan Gu; Jinchang Wang; Qiang Tang. Pavement Analysis and Design by Multiphysics. Advances in Civil Engineering 2019, 2019, 1 -2.
AMA StyleXue Luo, Robert L. Lytton, Yuqing Zhang, Fan Gu, Jinchang Wang, Qiang Tang. Pavement Analysis and Design by Multiphysics. Advances in Civil Engineering. 2019; 2019 ():1-2.
Chicago/Turabian StyleXue Luo; Robert L. Lytton; Yuqing Zhang; Fan Gu; Jinchang Wang; Qiang Tang. 2019. "Pavement Analysis and Design by Multiphysics." Advances in Civil Engineering 2019, no. : 1-2.
Heavy metals are not only hazardous to environment and public health, but they degrade the physicochemical and biological properties of soils increasing difficulty to the redevelopment of contaminated sites. This study proposes a method for reinforcing contaminated soils with fiber and cement. The feasibility of using wheat straw as fiber reinforcement is discussed. The strength of heavy metal-contaminated soil reinforced with wheat straw and cement is investigated through laboratory testing. Twelve groups of soil samples were prepared at three fiber contents (i.e., 0.1%, 0.2%, and 0.3% by weight), three water contents (i.e., 9%, 12%, and 15%), and three cement contents (i.e., 5%, 7.5%, and 10% by weight). Unconfined compression strength (UCS) was tested after 28 days of curing period and various freeze-thaw cycles. The testing results show that the increase in the number of freeze-thaw cycles results in the decrease of UCS. The inclusion of fiber reinforcement within cemented soil causes an increase in the UCS and changes the brittle behavior of cemented soil to a more ductile one. The UCS of the fiber-reinforced soils first increases, then decreases with the increase of water content, and reaches the maximum value at the optimum moisture content.
Qiang Tang; Peixin Shi; Yu Zhang; Wei Liu; Lei Chen. Strength and Deformation Properties of Fiber and Cement Reinforced Heavy Metal-Contaminated Synthetic Soils. Advances in Materials Science and Engineering 2019, 2019, 1 -9.
AMA StyleQiang Tang, Peixin Shi, Yu Zhang, Wei Liu, Lei Chen. Strength and Deformation Properties of Fiber and Cement Reinforced Heavy Metal-Contaminated Synthetic Soils. Advances in Materials Science and Engineering. 2019; 2019 ():1-9.
Chicago/Turabian StyleQiang Tang; Peixin Shi; Yu Zhang; Wei Liu; Lei Chen. 2019. "Strength and Deformation Properties of Fiber and Cement Reinforced Heavy Metal-Contaminated Synthetic Soils." Advances in Materials Science and Engineering 2019, no. : 1-9.
As a by-product from the incineration of municipal solid waste, bottom ash has a broad application prospect of resource utilization. In this study, bottom ash was selected as partial aggregate alternative and used as roadbase materials. The cemented aggregate containing bottom ash was evaluated through both experimental and numerical analysis. According to the results, the unconfined compressive strength of samples increases with the curing time, and the failure strain of sample decreases with the curing time. The unconfined compressive strength and failure strain of samples are influenced by the types of bottom ash. The increase of compressive strength with the curing time can be attributed to that the hydration reaction of cement will be more complete when the curing time is longer. The representative value (7 days) of unconfined compressive strength of samples meets the strength requirement (≥2.5 MPa) of the road subbase layer of heavy traffic highway in China. Subsequently, the surface settlement decreases with the increase of the modulus and thickness of roadbase and the distance from the centerline, while the settlement increases with vehicle load increasing. The modulus of the roadbase is not the main influences on the pavement settlement, under the condition that the strength of samples meets the requirements. However, increasing the thickness of roadbase can reduce the settlement at the center of the pavement effectively.
Qiang Tang; Fan Gu; Hui Chen; Cong Lu; Yu Zhang. Mechanical Evaluation of Bottom Ash from Municipal Solid Waste Incineration Used in Roadbase. Advances in Civil Engineering 2018, 2018, 1 -8.
AMA StyleQiang Tang, Fan Gu, Hui Chen, Cong Lu, Yu Zhang. Mechanical Evaluation of Bottom Ash from Municipal Solid Waste Incineration Used in Roadbase. Advances in Civil Engineering. 2018; 2018 ():1-8.
Chicago/Turabian StyleQiang Tang; Fan Gu; Hui Chen; Cong Lu; Yu Zhang. 2018. "Mechanical Evaluation of Bottom Ash from Municipal Solid Waste Incineration Used in Roadbase." Advances in Civil Engineering 2018, no. : 1-8.
Sanitary landfilling is nowadays the most common way to eliminate municipal solid wastes. However, the durability of landfill is mainly determined by the anti-seepage property of vertical cutoff walls. As microorganism has proved effective in plugging micro-pores, and greatly enhance the barrier performance of cutoff wall for MSW landfills. In this study, Escherichia coli. was selected for preconditioning towards compacted soil specimens and the hydraulic behaviours of the specimens were evaluated. According to the results, the huge amounts of microbial exopolysaccharides produced by Escherichia coli. encountered in the soil pores and formed a pore plugging, eventually caused 81–95% decrease in the hydraulic conductivity, from the initial value 5.3 × 10−5–5.6 × 10−6 cm/s to the stable value 3.1 × 10−6–2.9 × 10−7 cm/s (dropped by 1–2 orders of magnitude). The introduction of clay leads to the increase of surface roughness inside the internal pores as well as the diminution of shear forces, resulted in more effective adhesion between microorganism colonization and the surface of the particles. Subsequently, an extensive parametric analysis was conducted by numerical simulation to investigate the transport behaviour of contaminant through vertical cutoff walls. Several decrease of orders of magnitude in the hydraulic conductivity from 1 × 10−8 to 1 × 10−10 m/s resulted in the dramatical increase of the breakthrough time by 431.2% which revealed that a low hydraulic conductivity was of significance for vertical cutoff walls to achieve desirable barrier performance.
Yu Zhang; Lingling Pan; Fei Wang; Ning Zhu; Qiang Tang; Wang Fei; Zhu Ning. Estimation of Vertical Barrier Performance Based on Microbial Improvement. Soil and Recycling Management in the Anthropocene Era 2018, 300 -307.
AMA StyleYu Zhang, Lingling Pan, Fei Wang, Ning Zhu, Qiang Tang, Wang Fei, Zhu Ning. Estimation of Vertical Barrier Performance Based on Microbial Improvement. Soil and Recycling Management in the Anthropocene Era. 2018; ():300-307.
Chicago/Turabian StyleYu Zhang; Lingling Pan; Fei Wang; Ning Zhu; Qiang Tang; Wang Fei; Zhu Ning. 2018. "Estimation of Vertical Barrier Performance Based on Microbial Improvement." Soil and Recycling Management in the Anthropocene Era , no. : 300-307.
The electroplating sludge may pose serious threat to human health and surrounding environment without safe treatment. This paper investigated the feasibility of using electroplating sludge as subgrade backfill materials, by evaluating the mechanical properties and environmental risk of the cement-coal fly ash solidified sludge. In this study, Portland cement and coal fly ash are used to solidify/stabilize the sludge. After curing for 7, 14, and 28 days, the stabilization/solidification sludge specimens were subject to a series of mechanical, leaching, and microcosmic tests. It was found that the compressive strength increased with the increase of cement content, curing time, and the cement replacement by coal fly ash besides water content. Among these factors, the impact of water content on the compressive strength is most noticeable. It was observed that the compressive strength declined by 87.1% when the water content increased from 0% to 10%. Besides, leaching tests showed that the amount of leaching heavy metals were under the standard limit. These results demonstrated utilization of electroplating sludge in subgrade backfill material may provide an alternative for the treatment of electroplating sludge.
Yu Zhang; Peixin Shi; Lijuan Chen; Qiang Tang. Utilization of Electroplating Sludge as Subgrade Backfill Materials: Mechanical and Environmental Risk Evaluation. Advances in Civil Engineering 2018, 2018, 1 -9.
AMA StyleYu Zhang, Peixin Shi, Lijuan Chen, Qiang Tang. Utilization of Electroplating Sludge as Subgrade Backfill Materials: Mechanical and Environmental Risk Evaluation. Advances in Civil Engineering. 2018; 2018 ():1-9.
Chicago/Turabian StyleYu Zhang; Peixin Shi; Lijuan Chen; Qiang Tang. 2018. "Utilization of Electroplating Sludge as Subgrade Backfill Materials: Mechanical and Environmental Risk Evaluation." Advances in Civil Engineering 2018, no. : 1-9.
The durability of landfill mainly relies on the anti-seepage characteristic of liner system. The accumulation of microbial biomass is effective in reducing the hydraulic conductivity of soils. This study aimed at evaluating the impact of the microorganism on the barrier performance of landfill liners. According to the results, Escherichia coli. produced huge amounts of extracellular polymeric substances and coalesced to form a confluent plugging biofilm. This microorganism eventually resulted in the decrease of soil permeability by 81%–95%. Meanwhile, the increase of surface roughness inside the internal pores improved the adhesion between microorganism colonization and particle surface. Subsequently, an extensive parametric sensitivity analysis was undertaken for evaluating the contaminant transport in landfill liners. Decreasing the hydraulic conductivity from 1 × 10−8 m/s to 1 × 10−10 m/s resulted in the increase of the breakthrough time by 345.2%. This indicates that a low hydraulic conductivity was essential for the liner systems to achieve desirable barrier performance.
Qiang Tang; Fan Gu; Yu Zhang; Yuqing Zhang; Jialin Mo. Impact of biological clogging on the barrier performance of landfill liners. Journal of Environmental Management 2018, 222, 44 -53.
AMA StyleQiang Tang, Fan Gu, Yu Zhang, Yuqing Zhang, Jialin Mo. Impact of biological clogging on the barrier performance of landfill liners. Journal of Environmental Management. 2018; 222 ():44-53.
Chicago/Turabian StyleQiang Tang; Fan Gu; Yu Zhang; Yuqing Zhang; Jialin Mo. 2018. "Impact of biological clogging on the barrier performance of landfill liners." Journal of Environmental Management 222, no. : 44-53.
This study investigated the desorption behavior of heavy metals, Zn(II) and Cu(II), in the contaminated soil using citric acid and citric acid-containing wastewater (CACW). Four influence factors, including soil contamination levels, dosage of citric acid, reaction time and soil pH were taken into account. Using the citric acid, the desorption reaction with heavy metals was rapid (i.e., less than 2 h). The removal percentage of Zn(II) and Cu(II) reached more than 90% for one type of Suzhou clay with a pH value of 6.58 and a contaminated level of Zn > 2.7 mg/g and Cu > 3.3 mg/g. The increase of soil pH inhibited the metal desorption. The desorption behavior predicted by Visual MINTEQ was in good agreement with the experimental results. The desorption behavior of Zn(II) and Cu(II) was governed by the affinity of sorption sites for heavy metals and the chelating of organic ligands. Soil contamination levels and contact time were investigated when using CACW as the desorbent. It was concluded that CACW was also effective in extracting Zn(II) and Cu(II) from soil surface. When the contact time between CACW and contaminated soil reached 2 h, the removal percentage of Zn(II) and Cu(II) increased to 33% and 60%, respectively. As a result, CACW that is usually treated as a waste product can be a promising washing solution for soil remediation.
Fan Gu; Yu Zhang; Qiang Tang; Cong Lu; Ting Zhou. Remediation of Zn(II)- and Cu(II)-Contaminated Soil Using Citric Acid and Citric Acid-Containing Wastewater. International Journal of Civil Engineering 2018, 16, 1607 -1619.
AMA StyleFan Gu, Yu Zhang, Qiang Tang, Cong Lu, Ting Zhou. Remediation of Zn(II)- and Cu(II)-Contaminated Soil Using Citric Acid and Citric Acid-Containing Wastewater. International Journal of Civil Engineering. 2018; 16 (11):1607-1619.
Chicago/Turabian StyleFan Gu; Yu Zhang; Qiang Tang; Cong Lu; Ting Zhou. 2018. "Remediation of Zn(II)- and Cu(II)-Contaminated Soil Using Citric Acid and Citric Acid-Containing Wastewater." International Journal of Civil Engineering 16, no. 11: 1607-1619.
Cement solidification/stabilization is widely used towards contaminated soil since it has a low price and significant improvement for the structural capacity of soil. To increase the usage of the solidified matrix, cement-solidified contaminated soil was used as road subgrade material. In this study, carbonation effect that reflected the durability on strength characteristics of cement-solidified contaminated soil and the settlement of pavement were evaluated through experimental and numerical analysis, respectively. According to results, compressive strengths of specimens with 1% Pb(II) under carbonation and standard curing range from 0.44 MPa to 1.17 MPa and 0.14 MPa to 2.67 MPa, respectively. The relatively low strengths were attributed to immobilization of heavy metal, which consumed part of SiO2, Al2O3, and CaO components in the cement or kaolin and reduced the hydration and pozzolanic reaction materials. This phenomenon further decreased the strength of solidified soils. The carbonation depth of 1% Cu(II) or Zn(II) contaminated soils was 18 mm, which significantly increased with the increase of curing time and contamination concentration. Furthermore, the finite element calculation results showed that surface settlements decreased with the increase of modulus of subgrade and the distance away from the center. At the center, the pavement settlement was proportional to the level of traffic load.
Yundong Zhou; Lingling Pan; Qiang Tang; Yu Zhang; Na Yang; Cong Lu. Evaluation of Carbonation Effects on Cement-Solidified Contaminated Soil Used in Road Subgrade. Advances in Materials Science and Engineering 2018, 2018, 1 -15.
AMA StyleYundong Zhou, Lingling Pan, Qiang Tang, Yu Zhang, Na Yang, Cong Lu. Evaluation of Carbonation Effects on Cement-Solidified Contaminated Soil Used in Road Subgrade. Advances in Materials Science and Engineering. 2018; 2018 ():1-15.
Chicago/Turabian StyleYundong Zhou; Lingling Pan; Qiang Tang; Yu Zhang; Na Yang; Cong Lu. 2018. "Evaluation of Carbonation Effects on Cement-Solidified Contaminated Soil Used in Road Subgrade." Advances in Materials Science and Engineering 2018, no. : 1-15.
Heavy metal-contaminated soil and wastewater have been attracting an increasing amount of attention due to the potential threat to the surrounding environment and human health. Thus, in this study, citric acid (CA) and citric acid-containing wastewater (CACW) were selected for an evaluation of the influence of the contamination level of the soil, the concentration of citric acid, the contact time, the soil pH, and the ionic interaction on the desorption characteristics of three heavy metals (i.e., Cr(III), Mn(II), and Ni(II)). According to the experimental results, a high concentration of citric acid, an acidic condition, a low level of contamination, and a lengthy contact time were found to be beneficial for desorbing the heavy metals from the contaminated soil. Based on the experimental and calculated results, the H+ ions and organic ligands made substantial contributions to the release and adsorption of the heavy metals. The metal ions on the low selectivity sorption sites were leached out earlier than those on the high selectivity sorption sites. The removal percentages of Cr(III), Mn(II), and Ni(II) using CA with a contact time of 6 h were 39.9%, 77.0%, and 62.8%, respectively. By using the CACW as a desorbent, the removal percentages of Cr(III), Mn(II), and Ni(II) with a contact time of 6 h reached 21.4%, 26.9%, and 63.4%, respectively. This suggests a promising practical application of CACW for removing heavy metals from contaminated soil.
Tang Qiang; Gu Fan; Gao Yufeng; Inui Toru; Katsumi Takeshi. Desorption characteristics of Cr(III), Mn(II), and Ni(II) in contaminated soil using citric acid and citric acid-containing wastewater. Soils and Foundations 2018, 58, 50 -64.
AMA StyleTang Qiang, Gu Fan, Gao Yufeng, Inui Toru, Katsumi Takeshi. Desorption characteristics of Cr(III), Mn(II), and Ni(II) in contaminated soil using citric acid and citric acid-containing wastewater. Soils and Foundations. 2018; 58 (1):50-64.
Chicago/Turabian StyleTang Qiang; Gu Fan; Gao Yufeng; Inui Toru; Katsumi Takeshi. 2018. "Desorption characteristics of Cr(III), Mn(II), and Ni(II) in contaminated soil using citric acid and citric acid-containing wastewater." Soils and Foundations 58, no. 1: 50-64.
As a by-product from the incineration of municipal solid waste (MSW), fly ash usually contains mobile heavy metals that may engender severe pollution when reused. In this study, fly ash was solidified with cement and a chelating agent to immobilize these polluting elements. The possibility of using the solidified fly ash for pavement materials was also assessed through mechanical and environmental perspectives. According to the results, the strength of solidified fly ash was found proportional to both the cement/fly ash ratio and curing time. This indicated that the increase of fly ash loading reduced the concentration of products from cement hydration, and thus destroyed the structure of the products of hydration. With the increase of freeze–thaw cycles, the compressive strength of cement-stabilized fly ash decreased between days 7 and 14, and then increased between days 14 and 28. Subsequently, the finite element analysis showed that placing the solidified fly ash layer as a pavement material between an unbound base course and subgrade was beneficial to prolong fatigue life and reduce rutting distress of asphalt pavements. Finally, leachability of metals from the mixtures was tested, which showed that leaching concentration decreased as the cement/ash ratio, curing time, and chelating agent content increased.
Qiang Tang; Yu Zhang; Yufeng Gao; Fan Gu. Use of cement-chelated, solidified, municipal solid waste incinerator (MSWI) fly ash for pavement material: mechanical and environmental evaluations. Canadian Geotechnical Journal 2017, 54, 1553 -1566.
AMA StyleQiang Tang, Yu Zhang, Yufeng Gao, Fan Gu. Use of cement-chelated, solidified, municipal solid waste incinerator (MSWI) fly ash for pavement material: mechanical and environmental evaluations. Canadian Geotechnical Journal. 2017; 54 (11):1553-1566.
Chicago/Turabian StyleQiang Tang; Yu Zhang; Yufeng Gao; Fan Gu. 2017. "Use of cement-chelated, solidified, municipal solid waste incinerator (MSWI) fly ash for pavement material: mechanical and environmental evaluations." Canadian Geotechnical Journal 54, no. 11: 1553-1566.