The performance of inclined pile group embedded in consolidating soil under surcharge load was investigated by experiment in comparison with vertical pile group and single pile under the same conditions; dragload, dow...The performance of inclined pile group embedded in consolidating soil under surcharge load was investigated by experiment in comparison with vertical pile group and single pile under the same conditions; dragload, downdrag, and layered soil settlement were measured. A three-dimensional numerical model was built via FLAC3D software, and verified by the experimental results. Influence factors, such as consolidation time, pile spacing, and pile tilt angle were analyzed. The results show that dragload of inclined pile group increases with the increase of consolidation time and pile spacing or the decrease of pile tilt angle. Downdrag of inclined pile group increases with the increase of consolidation time, pile spacing and pile tilt angle.展开更多
Since the increasing demand for arable land and low efficient and disordered use of rural residential land,land consolidation for rural settlement has become a hot issue in China.Many Chinese scientists studied the to...Since the increasing demand for arable land and low efficient and disordered use of rural residential land,land consolidation for rural settlement has become a hot issue in China.Many Chinese scientists studied the topic from different angles.However,there is no reference systematically summarizing and discussing feasibility of consolidating rural residential land into arable land.The authors listed and analyzed the calculation methods of consolidating rural residential land into arable land,and discussed the feasibility and reasonability of those methods.Moreover,this paper put forward the study orientation in this regard for providing references for relevant researches.展开更多
As the world economy develops in a globally-oriented way and world trade develops in an incorporate way, upgrading the competitiveness of our export commodities and trading efficiency have become the most important pr...As the world economy develops in a globally-oriented way and world trade develops in an incorporate way, upgrading the competitiveness of our export commodities and trading efficiency have become the most important problems in national economic development. In the 1990s, scientific progress is stimulating the growth of international trade and the revolution in regional structure and product展开更多
The Arab Spring is supposed to be the Arab world’s great changes and turmoil,but Iran has repeatedly become the focus in the following changes.Whether it is in the Syrian civil war,or strikes against ISIS,or the Qata...The Arab Spring is supposed to be the Arab world’s great changes and turmoil,but Iran has repeatedly become the focus in the following changes.Whether it is in the Syrian civil war,or strikes against ISIS,or the Qatar crisis,Iran repeatedly appeared.There are different attitudes towards Iran’s behavior.The Trump administration holds the opinion that Iran is展开更多
At the invitation of the Chinese Association for International Understanding (CAFIU), a 4-member Australian Rotary delegation visited China from April 8-14. As a staff member of CAFIU, I accompanied the delegation’s ...At the invitation of the Chinese Association for International Understanding (CAFIU), a 4-member Australian Rotary delegation visited China from April 8-14. As a staff member of CAFIU, I accompanied the delegation’s whole trip in China.Australian Rotary is the chapter of the Rotary International in Australia; most of its展开更多
In the wake of the inflow of international capital into China’s bicycle industry in the past decade, China’s domestic bicycle market is seeing fiercer competition, with production exceeding sales. The Phoenix Brand ...In the wake of the inflow of international capital into China’s bicycle industry in the past decade, China’s domestic bicycle market is seeing fiercer competition, with production exceeding sales. The Phoenix Brand bicycle, one of China’s ten famous brands, has been maintaining a high market share on the domestic market over the last展开更多
In cloud computing, server consolidation is the part where very few persons go through the same. By consolidating the unused server space, memory can be reused for another data allocation. The objective of this paper ...In cloud computing, server consolidation is the part where very few persons go through the same. By consolidating the unused server space, memory can be reused for another data allocation. The objective of this paper is to improve resource utilization. Residual resource fragmentation refers to the state of the data center where sufficient amount of residual resources are available for any new VM allocation. To achieve this, there are three methods followed here. Active physical servers are identified. Then the maximum utilization of the resources is found out. Finally the resources are allocated and scheduled using the developed algorithm. In this work, we have proposed a new algorithm enhanced cloud consolidating algorithm. This algorithm improves some of the qualities of the cloud consolidating algorithm. Here the allocation technique is based on the cost and the memory.展开更多
Experiments on consolidating process and mechanism of internal loose structures in heavy ingots are studied by taking stretching technology as example Considering various detecting indexes,the equivalent relationship...Experiments on consolidating process and mechanism of internal loose structures in heavy ingots are studied by taking stretching technology as example Considering various detecting indexes,the equivalent relationships of forging ratios which are required by different forging processes with parameters are gotten.Effective experimental methods and basis can be provided for the studying the of forging heavy ingots展开更多
Buses are the most critical part of urban-rural transit systems.However,bus transit services in urban-rural areas face a trade-offbetween the need for better services and the low profitability resulting from low trave...Buses are the most critical part of urban-rural transit systems.However,bus transit services in urban-rural areas face a trade-offbetween the need for better services and the low profitability resulting from low travel demand.In this study,we show that we can improve the utilization and profitability of urban-rural buses by merging freight transportation with passenger transportation.We developed a mixed-integer program to model and analyze the coordination between freight and passenger transportation in an urban-rural transit system.We then conducted a case study to evaluate the effectiveness of the proposed approach.The numerical results indicate that the consolidation of passenger and freight transportation significantly reduces the operation cost of logistics companies and improves the profit of bus companies.We finally discuss the consolidation’s positive impacts on logistics companies,bus service providers,and society.展开更多
Objective: To observe the clinical efficacy of acupuncture-moxibustion therapy of "banking up original qi and consolidating the foundation" for prevention and treatment of seasonal allergic rhinitis.Methods: Sixty...Objective: To observe the clinical efficacy of acupuncture-moxibustion therapy of "banking up original qi and consolidating the foundation" for prevention and treatment of seasonal allergic rhinitis.Methods: Sixty included patients were divided into two groups according to the random number table method with 30 patients in each group. In acupuncture group, warming-needle moxibustion was carried out at Zúsānlǐ(足三里ST 36), and cone moxibustion on Fùzǐ(附子Radix Aconiti Lateralis Praeparata) cake was conducted at Guānyuán(关元CV 4), Qìhǎi(气海CV 6) and Dàzhuī(大椎GV 14). The treatment was conducted in May or June(2 months before the onset of rhinitis in this area). The treatment was carried out for once every other day and three times per week. Treatment for 24 times was considered as 1 course of treatment. No intervention treatment was conducted in control group. The score of rhinitis symptom, the visual analogue scale(VAS) score changes of total nasal symptom score(TNSS) and total non-nasal symptom score(TNNSS) of patients in 2015 and in 2016 were observed, and the clinical efficacy of the two groups was compared.Results:(1) The score of rhinitis symptom, the VAS score changes of TNSS and TNNSS in acupuncture group in 2016 declined when compared with the results in 2015, which were 4.57 ±0.82 vs 9.40 ± 1.89,13.37 ± 4.01 vs 30.80 ±4.77 and 15.93 ±6.30 vs 46.13 ± 9.79(P〈 0.001), the results in acupuncture group after treatment were lower than that in control group at same time, which were 4.57 ±0.82 vs 7.53 ±2.06,13.37±4.01 vs 27.17±6.84,15.93±6.30 vs 35.53±11.69(all P〈0.001). According to comparison, there was no obvious difference in the results in control group at the two time points, which were 8.60 ±2.39 vs7.53 ± 2.06, 29.63 ± 6.30 vs 27.17 ± 6.84 and 40.90 ±12.31 vs 35.53± 11.69(all P〉 0.05).(2) The total effective rate was 96.7%(29/30) in acupuncture group and 10%(3/30) in control group, and the difference was statistically significant(P〈 0.001).Conclusion: Acupuncture-moxibustion therapy of "banking up original qi and consolidating the foundation" was effective on prevention and treatment of seasonal allergic rhinitis.展开更多
Vertical drains are used to accelerate consolidation of clays in ground improvement projects.Smear zones exist around these drains,where permeability is reduced due to soil disturbance caused by the installation proce...Vertical drains are used to accelerate consolidation of clays in ground improvement projects.Smear zones exist around these drains,where permeability is reduced due to soil disturbance caused by the installation process.Hansbo solution is widely used in practice to consider the effects of drain discharge capacity and smear on the consolidation process.In this study,a computationally efficient diameter reduction method(DRM)obtained from the Hansbo solution is proposed to consider the smear effect without the need to model the smear zone physically.Validated by analytical and numerical results,a diameter reduction factor is analytically derived to reduce the diameter of the drain,while achieving similar solutions of pore pressure dissipation profile as the classical full model of the smear zone and drain.With the DRM,the excess pore pressure u obtained from the reduced drain in the original un-disturbed soil zone is accurate enough for practical applications in numerical models.Such performance of DRM is independent of soil material property.Results also show equally accurate performance of DRM under conditions of multi-layered soils and coupled radial-vertical groundwater flow.展开更多
The utilization of stone columns has emerged as a popular ground improvement strategy,whereas the drainage performance can be adversely hampered by clogging effect.Despite the ample progress of calculation methods for...The utilization of stone columns has emerged as a popular ground improvement strategy,whereas the drainage performance can be adversely hampered by clogging effect.Despite the ample progress of calculation methods for the consolidation of stone column-improved ground,theoretical investigations into the clogging effect have not been thoroughly explored.Furthermore,it is imperative to involve the column consolidation deformation to mitigate computational error on the consolidation of composite ground with high replacement ratios.In this context,an analytical model accounting for the initial clogging and coupled time and depth-dependent clogging of stone columns is established.Then,the resulting governing equations and analytical solutions are obtained under a new flow continuity relationship to incorporate column consolidation deformation.The accuracy and reliability of the proposed model are illustrated by degradation analysis and case studies with good agreements.Subsequently,the computed results of the current study are juxtaposed against the existing models,and an in-depth assessment of the impacts of several crucial parameters on the consolidation behavior is conducted.The results reveal that ignoring column consolidation deformation leads to an overestimate of the consolidation rate,with maximum error reaching up to 16%as the replacement ratio increases.Furthermore,the initial clogging also has a significant influence on the consolidation performance.Additionally,the increment of depth and time-clogging factors a and b will induce a noticeable retardation of the consolidation process,particularly in the later stage.展开更多
Deep coalbed methane(DCBM),an unconventional gas reservoir,has undergone significant advancements in recent years,sparking a growing interest in assessing pore pressure dynamics within these reservoirs.While some prod...Deep coalbed methane(DCBM),an unconventional gas reservoir,has undergone significant advancements in recent years,sparking a growing interest in assessing pore pressure dynamics within these reservoirs.While some production data analysis techniques have been adapted from conventional oil and gas wells,there remains a gap in the understanding of pore pressure generation and evolution,particularly in wells subjected to large-scale hydraulic fracturing.To address this gap,a novel technique called excess pore pressure analysis(EPPA)has been introduced to the coal seam gas industry for the first time to our knowledge,which employs dual-phase flow principles based on consolidation theory.This technique focuses on the generation and dissipation for excess pore-water pressure(EPWP)and excess pore-gas pressure(EPGP)in stimulated deep coal reservoirs.Equations have been developed respectively and numerical solutions have been provided using the finite element method(FEM).Application of this model to a representative field example reveals that excess pore pressure arises from rapid loading,with overburden weight transferred under undrained condition due to intense hydraulic fracturing,which significantly redistributes the weight-bearing role from the solid coal structure to the injected fluid and liberated gas within artificial pores over a brief timespan.Furthermore,field application indicates that the dissipation of EPWP and EPGP can be actually considered as the process of well production,where methane and water are extracted from deep coalbed methane wells,leading to consolidation for the artificial reservoirs.Moreover,history matching results demonstrate that the excess-pressure model established in this study provides a better explanation for the declining trends observed in both gas and water production curves,compared to conventional practices in coalbed methane reservoir engineering and petroleum engineering.This research not only enhances the understanding of DCBM reservoir behavior but also offers insights applicable to production analysis in other unconventional resources reliant on hydraulic fracturing.展开更多
Virtual machine(VM)consolidation aims to run VMs on the least number of physical machines(PMs).The optimal consolidation significantly reduces energy consumption(EC),quality of service(QoS)in applications,and resource...Virtual machine(VM)consolidation aims to run VMs on the least number of physical machines(PMs).The optimal consolidation significantly reduces energy consumption(EC),quality of service(QoS)in applications,and resource utilization.This paper proposes a prediction-basedmulti-objective VMconsolidation approach to search for the best mapping between VMs and PMs with good timeliness and practical value.We use a hybrid model based on Auto-Regressive Integrated Moving Average(ARIMA)and Support Vector Regression(SVR)(HPAS)as a prediction model and consolidate VMs to PMs based on prediction results by HPAS,aiming at minimizing the total EC,performance degradation(PD),migration cost(MC)and resource wastage(RW)simultaneously.Experimental results usingMicrosoft Azure trace show the proposed approach has better prediction accuracy and overcomes the multi-objective consolidation approach without prediction(i.e.,Non-dominated sorting genetic algorithm 2,Nsga2)and the renowned Overload Host Detection(OHD)approaches without prediction,such as Linear Regression(LR),Median Absolute Deviation(MAD)and Inter-Quartile Range(IQR).展开更多
his study focused on exploring the specificity of mechanical behavior for completely weathered granite,as a special soil,by consolidated drained triaxial tests.The influences of dry density(1.60,1.70,1.80 and 1.90 g/c...his study focused on exploring the specificity of mechanical behavior for completely weathered granite,as a special soil,by consolidated drained triaxial tests.The influences of dry density(1.60,1.70,1.80 and 1.90 g/cm^(3)),confining pressure(100,200,400 and 600 kPa),and moisture content(13.0%,that is,natural moisture content)were investigated in the present work.A newly developed Duncan-Chang model was established based on the experimental data and Duncan-Chang model.The influence of each parameter on the type of the proposed model curve was also evaluated.The experimental results revealed that with varying dry density and confining pressure,the deviatoric stress–strain curves have diversified characteristics including strain-softening,strain-stabilization and strain-hardening.Under high confining pressure condition,specimens with different densities all showed strain-hardening characteristic.Whereas at the low confining pressure levels,specimens with higher densities gradually transform into softening characteristics.Except for individual compression shear failure,the deformation modes of the specimens all showed swelling deformation,and all the damaged specimens maintained good integrity.Through comparing the experiment results,the strain-softening or strain-hardening behavior of CWG specimens could be predicted following the proposed model with high accuracy.Additionally,the proposed model can accurately characterize the key mechanical indicators,such as tangent modulus,peak value and residual strength,which is simple to implement and depends on fewer parameters.展开更多
Aerosol deposition(AD)method is a kind of additive manufacturing technology for fabricating dense films such as metals and ceramics at room temperature.It resolves the challenge of integrating ceramic films onto tempe...Aerosol deposition(AD)method is a kind of additive manufacturing technology for fabricating dense films such as metals and ceramics at room temperature.It resolves the challenge of integrating ceramic films onto temperaturesensitive substrates,including metals,glasses,and polymers.It should be emphasized that the AD is a spray coating technology that uses powder without thermal assistance to generate films with high density.Compared to the traditional sputter-based approach,the AD shows several advantages in efficiency,convenience,better interfacial bonding and so on.Therefore,it opens some possibilities to the field of batteries,especially all-solidstate batteries(ASSBs)and draws much attention not only for research but also for large scale applications.The purpose of this work is to provide a critical review on the science and technology of AD as well as its applications in the field of batteries.The process,mechanism and effective parameters of AD,and recent developments in AD applications in the field of batteries will be systematically reviewed so that a trend for AD will be finally provided.展开更多
The wave-induced liquefaction of seabed is responsible for causing damage to marine structures.Particle composition and consolidation degree are the key factors affecting the pore water pressure response and liquefact...The wave-induced liquefaction of seabed is responsible for causing damage to marine structures.Particle composition and consolidation degree are the key factors affecting the pore water pressure response and liquefaction behavior of the seabed under wave action.The present study conducted wave flume experiments on silt and silty fine sand beds with varying particle compositions.Furthermore,a comprehensive analysis of the differences and underlying reasons for liquefaction behavior in two different types of soil was conducted from both macroscopic and microscopic perspectives.The experimental results indicate that the silt bed necessitates a lower wave load intensity to attain the liquefaction state in comparison to the silty fine sand bed.Additionally,the duration and development depth of liquefaction are greater in the silt bed.The dissimilarity in liquefaction behavior between the two types of soil can be attributed to the variation in their permeability and plastic deformation capacity.The permeability coefficient and compression modulus of silt are lower than those of silty fine sand.Consequently,silt is more prone to the accumulation of pore pressure and subsequent liquefaction under external loading.Prior research has demonstrated that silt beds with varying consolidation degrees exhibit distinct initial failure modes.Specifically,a dense bed undergoes shear failure,whereas a loose bed experiences initial liquefaction failure.This study utilized discrete element simulation to examine the microscopic mechanisms that underlie this phenomenon.展开更多
Clay,as the most common soil used for foundationfill,is widely used in various infrastructure projects.The phy-sical and mechanical properties of clay are influenced by the pore solution environment.This study uses a GD...Clay,as the most common soil used for foundationfill,is widely used in various infrastructure projects.The phy-sical and mechanical properties of clay are influenced by the pore solution environment.This study uses a GDS static/dynamic triaxial apparatus and nuclear magnetic resonance experiments to investigate the effects of cyclic loading on clay foundations.Moreover,the development of cumulative strain in clay is analyzed,and afitting model for cumulative plastic strain is introduced by considering factors such as NaCl solution concentration,con-solidation stress ratio,and cycle number.In particular,the effects of the NaCl solution concentration and con-solidation stress ratio on the pore distribution of the test samples before and after cyclic loading are examined,and the relationship between microscopic pore size and macroscopic cumulative strain is obtained accordingly.Our results show that as the consolidation stress ratio grows,an increasing number of large pores in the soil samples are transformed into small pores.As the NaCl solution concentration becomes higher,the number of small pores gradually decreases,while the number of large pores remains unchanged.Cyclic loading causes the disappearance of the large pores in the samples,and the average pore size before cyclic loading is posi-tively correlated with the axial cumulative strain after cyclic loading.The cumulative strain produced by the soil under cyclic loading is inversely proportional to the NaCl solution concentration and consolidation stress ratio.展开更多
基金Supported by National Natural Science Foundation of China (No. 51008116)State Key Laboratory of Coastal and Offshore Engineering (No. LP1014)+1 种基金Fundamental Research Funds for the Central Universities (No. 2009B14514)China Postdoctoral Science Foundation (No. 20090461062)
文摘The performance of inclined pile group embedded in consolidating soil under surcharge load was investigated by experiment in comparison with vertical pile group and single pile under the same conditions; dragload, downdrag, and layered soil settlement were measured. A three-dimensional numerical model was built via FLAC3D software, and verified by the experimental results. Influence factors, such as consolidation time, pile spacing, and pile tilt angle were analyzed. The results show that dragload of inclined pile group increases with the increase of consolidation time and pile spacing or the decrease of pile tilt angle. Downdrag of inclined pile group increases with the increase of consolidation time, pile spacing and pile tilt angle.
基金Supported by the Foundation of Key Laboratory of Resources Remote Sensing and Digital Agriculture of Chinese Ministry of Agriculture (RDA0910)the Commonweal Foundation of China's National Academy(200990124)+1 种基金Major Program of National Natural Science Foundation of China(40930101)National Key Technologies R & D Program of China(2006BAC08B0404)~~
文摘Since the increasing demand for arable land and low efficient and disordered use of rural residential land,land consolidation for rural settlement has become a hot issue in China.Many Chinese scientists studied the topic from different angles.However,there is no reference systematically summarizing and discussing feasibility of consolidating rural residential land into arable land.The authors listed and analyzed the calculation methods of consolidating rural residential land into arable land,and discussed the feasibility and reasonability of those methods.Moreover,this paper put forward the study orientation in this regard for providing references for relevant researches.
文摘As the world economy develops in a globally-oriented way and world trade develops in an incorporate way, upgrading the competitiveness of our export commodities and trading efficiency have become the most important problems in national economic development. In the 1990s, scientific progress is stimulating the growth of international trade and the revolution in regional structure and product
文摘The Arab Spring is supposed to be the Arab world’s great changes and turmoil,but Iran has repeatedly become the focus in the following changes.Whether it is in the Syrian civil war,or strikes against ISIS,or the Qatar crisis,Iran repeatedly appeared.There are different attitudes towards Iran’s behavior.The Trump administration holds the opinion that Iran is
文摘At the invitation of the Chinese Association for International Understanding (CAFIU), a 4-member Australian Rotary delegation visited China from April 8-14. As a staff member of CAFIU, I accompanied the delegation’s whole trip in China.Australian Rotary is the chapter of the Rotary International in Australia; most of its
文摘In the wake of the inflow of international capital into China’s bicycle industry in the past decade, China’s domestic bicycle market is seeing fiercer competition, with production exceeding sales. The Phoenix Brand bicycle, one of China’s ten famous brands, has been maintaining a high market share on the domestic market over the last
文摘In cloud computing, server consolidation is the part where very few persons go through the same. By consolidating the unused server space, memory can be reused for another data allocation. The objective of this paper is to improve resource utilization. Residual resource fragmentation refers to the state of the data center where sufficient amount of residual resources are available for any new VM allocation. To achieve this, there are three methods followed here. Active physical servers are identified. Then the maximum utilization of the resources is found out. Finally the resources are allocated and scheduled using the developed algorithm. In this work, we have proposed a new algorithm enhanced cloud consolidating algorithm. This algorithm improves some of the qualities of the cloud consolidating algorithm. Here the allocation technique is based on the cost and the memory.
文摘Experiments on consolidating process and mechanism of internal loose structures in heavy ingots are studied by taking stretching technology as example Considering various detecting indexes,the equivalent relationships of forging ratios which are required by different forging processes with parameters are gotten.Effective experimental methods and basis can be provided for the studying the of forging heavy ingots
文摘Buses are the most critical part of urban-rural transit systems.However,bus transit services in urban-rural areas face a trade-offbetween the need for better services and the low profitability resulting from low travel demand.In this study,we show that we can improve the utilization and profitability of urban-rural buses by merging freight transportation with passenger transportation.We developed a mixed-integer program to model and analyze the coordination between freight and passenger transportation in an urban-rural transit system.We then conducted a case study to evaluate the effectiveness of the proposed approach.The numerical results indicate that the consolidation of passenger and freight transportation significantly reduces the operation cost of logistics companies and improves the profit of bus companies.We finally discuss the consolidation’s positive impacts on logistics companies,bus service providers,and society.
基金Supported by Baotou Medical Science and Technology Project:Wsjj2015060~~
文摘Objective: To observe the clinical efficacy of acupuncture-moxibustion therapy of "banking up original qi and consolidating the foundation" for prevention and treatment of seasonal allergic rhinitis.Methods: Sixty included patients were divided into two groups according to the random number table method with 30 patients in each group. In acupuncture group, warming-needle moxibustion was carried out at Zúsānlǐ(足三里ST 36), and cone moxibustion on Fùzǐ(附子Radix Aconiti Lateralis Praeparata) cake was conducted at Guānyuán(关元CV 4), Qìhǎi(气海CV 6) and Dàzhuī(大椎GV 14). The treatment was conducted in May or June(2 months before the onset of rhinitis in this area). The treatment was carried out for once every other day and three times per week. Treatment for 24 times was considered as 1 course of treatment. No intervention treatment was conducted in control group. The score of rhinitis symptom, the visual analogue scale(VAS) score changes of total nasal symptom score(TNSS) and total non-nasal symptom score(TNNSS) of patients in 2015 and in 2016 were observed, and the clinical efficacy of the two groups was compared.Results:(1) The score of rhinitis symptom, the VAS score changes of TNSS and TNNSS in acupuncture group in 2016 declined when compared with the results in 2015, which were 4.57 ±0.82 vs 9.40 ± 1.89,13.37 ± 4.01 vs 30.80 ±4.77 and 15.93 ±6.30 vs 46.13 ± 9.79(P〈 0.001), the results in acupuncture group after treatment were lower than that in control group at same time, which were 4.57 ±0.82 vs 7.53 ±2.06,13.37±4.01 vs 27.17±6.84,15.93±6.30 vs 35.53±11.69(all P〈0.001). According to comparison, there was no obvious difference in the results in control group at the two time points, which were 8.60 ±2.39 vs7.53 ± 2.06, 29.63 ± 6.30 vs 27.17 ± 6.84 and 40.90 ±12.31 vs 35.53± 11.69(all P〉 0.05).(2) The total effective rate was 96.7%(29/30) in acupuncture group and 10%(3/30) in control group, and the difference was statistically significant(P〈 0.001).Conclusion: Acupuncture-moxibustion therapy of "banking up original qi and consolidating the foundation" was effective on prevention and treatment of seasonal allergic rhinitis.
基金The authors wish to acknowledge the generous financial sup-port from the Singapore Maritime Institute(SMI)for this research within the project‘Evaluation of In-situ Consolidation of Dredged and Excavated Materials at Reclaimed Next Generation Tuas Port’(Project ID:SMI-2018-MA-01).
文摘Vertical drains are used to accelerate consolidation of clays in ground improvement projects.Smear zones exist around these drains,where permeability is reduced due to soil disturbance caused by the installation process.Hansbo solution is widely used in practice to consider the effects of drain discharge capacity and smear on the consolidation process.In this study,a computationally efficient diameter reduction method(DRM)obtained from the Hansbo solution is proposed to consider the smear effect without the need to model the smear zone physically.Validated by analytical and numerical results,a diameter reduction factor is analytically derived to reduce the diameter of the drain,while achieving similar solutions of pore pressure dissipation profile as the classical full model of the smear zone and drain.With the DRM,the excess pore pressure u obtained from the reduced drain in the original un-disturbed soil zone is accurate enough for practical applications in numerical models.Such performance of DRM is independent of soil material property.Results also show equally accurate performance of DRM under conditions of multi-layered soils and coupled radial-vertical groundwater flow.
基金funding support from the National Natural Science Foundation of China(Grant Nos.52178373 and 51878657).
文摘The utilization of stone columns has emerged as a popular ground improvement strategy,whereas the drainage performance can be adversely hampered by clogging effect.Despite the ample progress of calculation methods for the consolidation of stone column-improved ground,theoretical investigations into the clogging effect have not been thoroughly explored.Furthermore,it is imperative to involve the column consolidation deformation to mitigate computational error on the consolidation of composite ground with high replacement ratios.In this context,an analytical model accounting for the initial clogging and coupled time and depth-dependent clogging of stone columns is established.Then,the resulting governing equations and analytical solutions are obtained under a new flow continuity relationship to incorporate column consolidation deformation.The accuracy and reliability of the proposed model are illustrated by degradation analysis and case studies with good agreements.Subsequently,the computed results of the current study are juxtaposed against the existing models,and an in-depth assessment of the impacts of several crucial parameters on the consolidation behavior is conducted.The results reveal that ignoring column consolidation deformation leads to an overestimate of the consolidation rate,with maximum error reaching up to 16%as the replacement ratio increases.Furthermore,the initial clogging also has a significant influence on the consolidation performance.Additionally,the increment of depth and time-clogging factors a and b will induce a noticeable retardation of the consolidation process,particularly in the later stage.
基金supported by the National Natural Science Foundation of China(Nos.42272195 and 42130802)supported by the Key Applied Science and Technology Project of PetroChina(No.2023ZZ18)the Major Science and Technology Project of Changqing Oilfield(No.2023DZZ01).
文摘Deep coalbed methane(DCBM),an unconventional gas reservoir,has undergone significant advancements in recent years,sparking a growing interest in assessing pore pressure dynamics within these reservoirs.While some production data analysis techniques have been adapted from conventional oil and gas wells,there remains a gap in the understanding of pore pressure generation and evolution,particularly in wells subjected to large-scale hydraulic fracturing.To address this gap,a novel technique called excess pore pressure analysis(EPPA)has been introduced to the coal seam gas industry for the first time to our knowledge,which employs dual-phase flow principles based on consolidation theory.This technique focuses on the generation and dissipation for excess pore-water pressure(EPWP)and excess pore-gas pressure(EPGP)in stimulated deep coal reservoirs.Equations have been developed respectively and numerical solutions have been provided using the finite element method(FEM).Application of this model to a representative field example reveals that excess pore pressure arises from rapid loading,with overburden weight transferred under undrained condition due to intense hydraulic fracturing,which significantly redistributes the weight-bearing role from the solid coal structure to the injected fluid and liberated gas within artificial pores over a brief timespan.Furthermore,field application indicates that the dissipation of EPWP and EPGP can be actually considered as the process of well production,where methane and water are extracted from deep coalbed methane wells,leading to consolidation for the artificial reservoirs.Moreover,history matching results demonstrate that the excess-pressure model established in this study provides a better explanation for the declining trends observed in both gas and water production curves,compared to conventional practices in coalbed methane reservoir engineering and petroleum engineering.This research not only enhances the understanding of DCBM reservoir behavior but also offers insights applicable to production analysis in other unconventional resources reliant on hydraulic fracturing.
基金funded by Science and Technology Department of Shaanxi Province,Grant Numbers:2019GY-020 and 2024JC-YBQN-0730.
文摘Virtual machine(VM)consolidation aims to run VMs on the least number of physical machines(PMs).The optimal consolidation significantly reduces energy consumption(EC),quality of service(QoS)in applications,and resource utilization.This paper proposes a prediction-basedmulti-objective VMconsolidation approach to search for the best mapping between VMs and PMs with good timeliness and practical value.We use a hybrid model based on Auto-Regressive Integrated Moving Average(ARIMA)and Support Vector Regression(SVR)(HPAS)as a prediction model and consolidate VMs to PMs based on prediction results by HPAS,aiming at minimizing the total EC,performance degradation(PD),migration cost(MC)and resource wastage(RW)simultaneously.Experimental results usingMicrosoft Azure trace show the proposed approach has better prediction accuracy and overcomes the multi-objective consolidation approach without prediction(i.e.,Non-dominated sorting genetic algorithm 2,Nsga2)and the renowned Overload Host Detection(OHD)approaches without prediction,such as Linear Regression(LR),Median Absolute Deviation(MAD)and Inter-Quartile Range(IQR).
基金Project(42202318)supported by the National Natural Science Foundation of China。
文摘his study focused on exploring the specificity of mechanical behavior for completely weathered granite,as a special soil,by consolidated drained triaxial tests.The influences of dry density(1.60,1.70,1.80 and 1.90 g/cm^(3)),confining pressure(100,200,400 and 600 kPa),and moisture content(13.0%,that is,natural moisture content)were investigated in the present work.A newly developed Duncan-Chang model was established based on the experimental data and Duncan-Chang model.The influence of each parameter on the type of the proposed model curve was also evaluated.The experimental results revealed that with varying dry density and confining pressure,the deviatoric stress–strain curves have diversified characteristics including strain-softening,strain-stabilization and strain-hardening.Under high confining pressure condition,specimens with different densities all showed strain-hardening characteristic.Whereas at the low confining pressure levels,specimens with higher densities gradually transform into softening characteristics.Except for individual compression shear failure,the deformation modes of the specimens all showed swelling deformation,and all the damaged specimens maintained good integrity.Through comparing the experiment results,the strain-softening or strain-hardening behavior of CWG specimens could be predicted following the proposed model with high accuracy.Additionally,the proposed model can accurately characterize the key mechanical indicators,such as tangent modulus,peak value and residual strength,which is simple to implement and depends on fewer parameters.
基金supported by National University of Singapore (Chongqing) Research InstituteNational University of Singapore+2 种基金Chongqing Postdoctoral Research Special FundingOverseas Postdoctoral Research Start-up FundingNatural Science Foundation of Chongqing, China (cstc2021jcyj-msxmX0086)
文摘Aerosol deposition(AD)method is a kind of additive manufacturing technology for fabricating dense films such as metals and ceramics at room temperature.It resolves the challenge of integrating ceramic films onto temperaturesensitive substrates,including metals,glasses,and polymers.It should be emphasized that the AD is a spray coating technology that uses powder without thermal assistance to generate films with high density.Compared to the traditional sputter-based approach,the AD shows several advantages in efficiency,convenience,better interfacial bonding and so on.Therefore,it opens some possibilities to the field of batteries,especially all-solidstate batteries(ASSBs)and draws much attention not only for research but also for large scale applications.The purpose of this work is to provide a critical review on the science and technology of AD as well as its applications in the field of batteries.The process,mechanism and effective parameters of AD,and recent developments in AD applications in the field of batteries will be systematically reviewed so that a trend for AD will be finally provided.
基金The National Natural Science Foundation of China under contract No.41976049the Opening Foundation of Marine Ecological Restoration and Smart Ocean Engineering Research Center of Hebei Province under contract No.HBMESO2306。
文摘The wave-induced liquefaction of seabed is responsible for causing damage to marine structures.Particle composition and consolidation degree are the key factors affecting the pore water pressure response and liquefaction behavior of the seabed under wave action.The present study conducted wave flume experiments on silt and silty fine sand beds with varying particle compositions.Furthermore,a comprehensive analysis of the differences and underlying reasons for liquefaction behavior in two different types of soil was conducted from both macroscopic and microscopic perspectives.The experimental results indicate that the silt bed necessitates a lower wave load intensity to attain the liquefaction state in comparison to the silty fine sand bed.Additionally,the duration and development depth of liquefaction are greater in the silt bed.The dissimilarity in liquefaction behavior between the two types of soil can be attributed to the variation in their permeability and plastic deformation capacity.The permeability coefficient and compression modulus of silt are lower than those of silty fine sand.Consequently,silt is more prone to the accumulation of pore pressure and subsequent liquefaction under external loading.Prior research has demonstrated that silt beds with varying consolidation degrees exhibit distinct initial failure modes.Specifically,a dense bed undergoes shear failure,whereas a loose bed experiences initial liquefaction failure.This study utilized discrete element simulation to examine the microscopic mechanisms that underlie this phenomenon.
文摘Clay,as the most common soil used for foundationfill,is widely used in various infrastructure projects.The phy-sical and mechanical properties of clay are influenced by the pore solution environment.This study uses a GDS static/dynamic triaxial apparatus and nuclear magnetic resonance experiments to investigate the effects of cyclic loading on clay foundations.Moreover,the development of cumulative strain in clay is analyzed,and afitting model for cumulative plastic strain is introduced by considering factors such as NaCl solution concentration,con-solidation stress ratio,and cycle number.In particular,the effects of the NaCl solution concentration and con-solidation stress ratio on the pore distribution of the test samples before and after cyclic loading are examined,and the relationship between microscopic pore size and macroscopic cumulative strain is obtained accordingly.Our results show that as the consolidation stress ratio grows,an increasing number of large pores in the soil samples are transformed into small pores.As the NaCl solution concentration becomes higher,the number of small pores gradually decreases,while the number of large pores remains unchanged.Cyclic loading causes the disappearance of the large pores in the samples,and the average pore size before cyclic loading is posi-tively correlated with the axial cumulative strain after cyclic loading.The cumulative strain produced by the soil under cyclic loading is inversely proportional to the NaCl solution concentration and consolidation stress ratio.