In this study,we propose a drainage pipe pile under vacuum consolidation to integrate foundation treatment and pile foundation engineering in soft soil areas.To study its bearing capacity characteristics and foundatio...In this study,we propose a drainage pipe pile under vacuum consolidation to integrate foundation treatment and pile foundation engineering in soft soil areas.To study its bearing capacity characteristics and foundation treatment performance,single pile static load tests,vane shear tests,and water content tests were carried out for ordinary piles,perforated piles,and drainage pipe piles under conditions of static and vacuum consolidation.Based on the results,the concept of strong and weak reinforcement areas was proposed and used for bearing capacity prediction.The results showed that the drainage pipe pile did not become silted under vacuum consolidation.The single pile bearing capacity was much higher than that of an ordinary pile,and the pile side friction was exerted mainly in the middle and lower parts.Good results were achieved using the shear strength at the junction of the strong and weak reinforcement areas to estimate the ultimate bearing capacity of a single pile.This study provided important insights into the design and construction of drainage pipe piles in a soft soil foundation.展开更多
At present, in the municipal drainage pipe network project, the level of the construction quality of the project whether to play an important correlation. Municipal drainage pipe network engineering in the actual cons...At present, in the municipal drainage pipe network project, the level of the construction quality of the project whether to play an important correlation. Municipal drainage pipe network engineering in the actual construction, should be closely around the quality control of scientific and reasonable control, take targeted means to increase the quality control, understand the main factors affecting the quality of engineering, develop a scientific and reasonable construction means, to promote the project can play a due value. This paper explores the quality control of such projects.展开更多
The water carrying capacity and head loss of pipelines are significantly affected by the flow state,aiming at the problem that the transition flow characteristics of multi caliber basalt fiber drainage pipe are not cl...The water carrying capacity and head loss of pipelines are significantly affected by the flow state,aiming at the problem that the transition flow characteristics of multi caliber basalt fiber drainage pipe are not clear,based on the two-di-mensional numerical simulation results of multi-diameter pipes with barriers,this paper systematically analyzes the transition path and transition mecha-nism of the multi-diameter drainage pipe convection system under the action of barriers in the range of Re=10^(3)-2.73×10^(8).The results show that:1)The main mode solution of multi-aperture basalt fiber drainage pipe convection system is steady flow in the process of transition to chaos.2)Compared with the non-barrier condition,the transition process of the multi-aperture basalt fiber drainage pipe with the barrier is obviously delayed,that is,the critical Reynolds number of the convective system evolving from laminar flow to tur-bulent flow is larger.The research results show that the design of the barrier can effectively improve the water conveyance capacity of the pipeline,which can provide reference for the optimal design of multi-diameter drainage pipes.展开更多
Effective urban land-use re-planning and the strategic arrangement of drainage pipe networks can significantly enhance urban flood defense capacity.Aimed at reducing the potential risks of urban flooding,this paper pr...Effective urban land-use re-planning and the strategic arrangement of drainage pipe networks can significantly enhance urban flood defense capacity.Aimed at reducing the potential risks of urban flooding,this paper presents a straightforward and efficient approach to an urban distributed runoff model(UDRM).The model is developed to quantify the discharge and water depth within urban drainage pipe networks under varying rainfall intensities and land-use scenarios.The Nash efficiency coefficient of UDRM exceeds 0.9,which indicates its high computational efficiency and potential benefit in predicting urban flooding.The prediction of drainage conditions under both current and re-planned land-use types is achieved by adopting different flood recurrence intervals.The findings reveal that the re-planned land-use strategies could effectively diminish flood risk upstream of the drainage pipe network across 20-year and 50-year flood recurrence intervals.However,in the case of extreme rainfall events(a 100-year flood recurrence),the re-planned land-use approach fell short of fulfilling the requirements necessary for flood disaster mitigation.In these instances,the adoption of larger-diameter drainage pipes becomes an essential requisite to satisfy drainage needs.Accordingly,the proposed UDRM effectively combines land-use information with pipeline data to give practical suggestions for pipeline modification and land-use optimization to combat urban floods.Therefore,this methodology warrants further promotion in the field of urban re-planning.展开更多
Developing effective irrigation and drainage strategies to improve the quality of saline-alkali soil is vital for enhancing agricultural production and increasing economic returns. In this study, we explored how irrig...Developing effective irrigation and drainage strategies to improve the quality of saline-alkali soil is vital for enhancing agricultural production and increasing economic returns. In this study, we explored how irrigation and drainage modes (flood irrigation, drip irrigation, and sub-surface pipe drainage under drip irrigation) improve the saline-alkali soil in Xinjiang, China. We aimed to study the transport characteristics of soil water and salt under different irrigation and drainage modes, and analyze the effects of the combination of irrigation and drainage on soil salt leaching, as well as its impacts on the growth of oil sunflower. Our results show that sub-surface pipe drainage under drip irrigation significantly reduced the soil salt content and soil water content at the 0–200 cm soil depth. Under sub-surface pipe drainage combined with drip irrigation, the mean soil salt content was reduced to below 10 g/kg after the second irrigation, and the soil salt content decreased as sub-surface pipe distance decreased. The mean soil salt content of flood irrigation exceeded 25 g/kg, and the mean soil desalination efficiency was 3.28%, which was lower than that of drip irrigation. The mean soil desalination rate under drip irrigation and sub-surface pipe drainage under drip irrigation was 19.30% and 58.12%, respectively. After sub-surface drainage regulation under drip irrigation, the germination percentage of oil sunflower seedlings was increased to more than 50%, which further confirmed that combined drip irrigation and sub-surface pipe drainage is very effective in improving the quality of saline-alkali soil and increasing the productivity of agricultural crops.展开更多
Due to the frequent leakage of pipes and valves in the current water supply and drainage system engineering, water resources are wasted and the overall engineering quality is poor. The design of water supply and drain...Due to the frequent leakage of pipes and valves in the current water supply and drainage system engineering, water resources are wasted and the overall engineering quality is poor. The design of water supply and drainage system for green buildings is studied. Obtain the water supply and drainage volume and design the maximum daily water consumption. Select water supply and drainage mode, and use frequency conversion water supply and shunt system to realize water supply and drainage of buildings. Water supply and drainage equipment and pipes are selected to ensure construction quality. Water supply and drainage design model is built based on BIM, and pipeline space is reserved. Arrange and lay water supply and drainage pipelines to complete the design of water supply and drainage system for engineering buildings. Through the demonstration and analysis of examples, the system effectively reduces the sewage discharge and tap water consumption, has good energy-saving effect, and generally meets the requirements of two stars for green buildings, which proves the reliability of the system.展开更多
Many dangerous effects arise from seepage through earth dams based on pervious layer. Therefore, the dam embankment must be provided with seepage control measures to avoid such effects. In the present work, different ...Many dangerous effects arise from seepage through earth dams based on pervious layer. Therefore, the dam embankment must be provided with seepage control measures to avoid such effects. In the present work, different control methods were used such as flat slopes, toe drainage systems, and a catch drain in the tail water. The hydraulic performance of each control measure was evaluated using the analytical solutions, previously developed, to estimate the seepage quantity (q), the height of seepage surface (h<sub>3</sub>), and the coordinates of the free surface (h<sub>x</sub>). Study was conducted on a physical model for a dam embankment having a top width (b) = 10.0 meter, height (H<sub>d</sub>) = 30.0 meter, and slope factor (m) = 1.5. The obtained results were analyzed and presented in dimensionless charts. Results showed that, the used control measures possess a great effect on the characteristics of seepage through earth dams based on pervious foundations. A comparative study was conducted between the studied toe drainage systems to enable the designers the better choice for design purposes.展开更多
In order to study the law of nitrogen leaching losses from the paddy field under the condition of drainage, based on the theories of potential energy and solute transport, a water nitrogen dynamic mixed model by comb...In order to study the law of nitrogen leaching losses from the paddy field under the condition of drainage, based on the theories of potential energy and solute transport, a water nitrogen dynamic mixed model by combining the flow net with dynamic method was established. In the computation of buried pipe drainage, the superposition principle was used to simplify the complex solving of the two dimensional problem about water nitrogen transportation in Soil Plant Air Continuous (SPAC) system into several one dimensional problems. The presented method is simple and practical. Some field experiments were carried out to demonstrate the validity of the model.展开更多
This study addressed the problem of low drainage efficiency or even no drainage in subsurface drainage systems buried in saturated-unsaturated zones above the water table.An indoor experiment on infiltration under pon...This study addressed the problem of low drainage efficiency or even no drainage in subsurface drainage systems buried in saturated-unsaturated zones above the water table.An indoor experiment on infiltration under ponded conditions in a homogeneous soil column was performed to study the effects of soil texture on the soil wetting front morphology,soil infiltration rate,drainage efficiency of the subsurface drainage pipe,vertical distribution of soil water content and salinity along the soil column.The results showed that the drainage process of subsurface drainage pipes above the water table was quite different from that of subsurface drainage pipes below the water table.When a subsurface drainage pipe was located in sandy soil,the migration of soil water toward the bottom of the drainage pipe was significant,and the water could not be discharged into the pipe.When the drainage pipe was located in loamy clay,the movement of soil water towards the bottom of the pipe was retarded,and the water could be discharged into the pipe.During the drainage process,the drainage of the pipe can produce nonequilibrium flow in the soil,and the continuity of the nonequilibrium flow can be affected by the hydraulic conductivity of the soil above the pipe,which can result in discontinuous drainage and low drainage efficiency.The water holding capacity,permeability and aeration of soil are important factors that affect the drainage under unsaturated conditions.Eliminating the hysteresis effect and capillary barrier around the drainage pipe and adjusting water holding capacity,the permeability and aeration of soil structure through a new subsurface drainage structure may enhance the drainage efficiency of subsurface drainage pipes in saturated-unsaturated zones.展开更多
Urban drainage pipe network is the backbone of urban drainage,flood control and water pollution prevention,and is also an essential symbol to measure the level of urban modernization.A large number of underground drai...Urban drainage pipe network is the backbone of urban drainage,flood control and water pollution prevention,and is also an essential symbol to measure the level of urban modernization.A large number of underground drainage pipe networks in aged urban areas have been laid for a long time and have reached or practically reached the service age.The repair of drainage pipe networks has attracted extensive attention from all walks of life.Since the Ministry of ecological environment and the national development and Reform Commission jointly issued the action plan for the Yangtze River Protection and restoration in 2019,various provinces in the Yangtze River Basin,such as Anhui,Jiangxi and Hunan,have extensively carried out PPp projects for urban pipeline restoration,in order to improve the quality and efficiency of sewage treatment.Based on the management practice of urban pipe network restoration project in Wuhu City,Anhui Province,this paper analyzes the problems of lengthy construction period and repeated operation caused by the mismatch between the design schedule of the restoration scheme and the construction schedule of the pipe network restoration in the existing project management mode,and proposes a model of urban drainage pipe network restoration scheme selection based on the improved support vector machine.The validity and feasibility of the model are analyzed and verified by collecting the data in the project practice.The research results show that the model has a favorable effect on the selection of urban drainage pipeline restoration schemes,and its accuracy can reach 90%.The research results can provide method guidance and technical support for the rapid decision-making of urban drainage pipeline restoration projects.展开更多
基金supported by the Key Water Science and Technology Project of Zhejiang Province(No.RB2027)the Zhejiang Provincial Public Welfare Technology Application Research Project(No.LGG22E080002),China。
文摘In this study,we propose a drainage pipe pile under vacuum consolidation to integrate foundation treatment and pile foundation engineering in soft soil areas.To study its bearing capacity characteristics and foundation treatment performance,single pile static load tests,vane shear tests,and water content tests were carried out for ordinary piles,perforated piles,and drainage pipe piles under conditions of static and vacuum consolidation.Based on the results,the concept of strong and weak reinforcement areas was proposed and used for bearing capacity prediction.The results showed that the drainage pipe pile did not become silted under vacuum consolidation.The single pile bearing capacity was much higher than that of an ordinary pile,and the pile side friction was exerted mainly in the middle and lower parts.Good results were achieved using the shear strength at the junction of the strong and weak reinforcement areas to estimate the ultimate bearing capacity of a single pile.This study provided important insights into the design and construction of drainage pipe piles in a soft soil foundation.
文摘At present, in the municipal drainage pipe network project, the level of the construction quality of the project whether to play an important correlation. Municipal drainage pipe network engineering in the actual construction, should be closely around the quality control of scientific and reasonable control, take targeted means to increase the quality control, understand the main factors affecting the quality of engineering, develop a scientific and reasonable construction means, to promote the project can play a due value. This paper explores the quality control of such projects.
基金supported by Sichuan Science and Technology Program of China(No.2024ZHYS0001).
文摘The water carrying capacity and head loss of pipelines are significantly affected by the flow state,aiming at the problem that the transition flow characteristics of multi caliber basalt fiber drainage pipe are not clear,based on the two-di-mensional numerical simulation results of multi-diameter pipes with barriers,this paper systematically analyzes the transition path and transition mecha-nism of the multi-diameter drainage pipe convection system under the action of barriers in the range of Re=10^(3)-2.73×10^(8).The results show that:1)The main mode solution of multi-aperture basalt fiber drainage pipe convection system is steady flow in the process of transition to chaos.2)Compared with the non-barrier condition,the transition process of the multi-aperture basalt fiber drainage pipe with the barrier is obviously delayed,that is,the critical Reynolds number of the convective system evolving from laminar flow to tur-bulent flow is larger.The research results show that the design of the barrier can effectively improve the water conveyance capacity of the pipeline,which can provide reference for the optimal design of multi-diameter drainage pipes.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFC3202002)the National Natural Science Foundation of China(Grant Nos.52025092,52209087 and 52379065).
文摘Effective urban land-use re-planning and the strategic arrangement of drainage pipe networks can significantly enhance urban flood defense capacity.Aimed at reducing the potential risks of urban flooding,this paper presents a straightforward and efficient approach to an urban distributed runoff model(UDRM).The model is developed to quantify the discharge and water depth within urban drainage pipe networks under varying rainfall intensities and land-use scenarios.The Nash efficiency coefficient of UDRM exceeds 0.9,which indicates its high computational efficiency and potential benefit in predicting urban flooding.The prediction of drainage conditions under both current and re-planned land-use types is achieved by adopting different flood recurrence intervals.The findings reveal that the re-planned land-use strategies could effectively diminish flood risk upstream of the drainage pipe network across 20-year and 50-year flood recurrence intervals.However,in the case of extreme rainfall events(a 100-year flood recurrence),the re-planned land-use approach fell short of fulfilling the requirements necessary for flood disaster mitigation.In these instances,the adoption of larger-diameter drainage pipes becomes an essential requisite to satisfy drainage needs.Accordingly,the proposed UDRM effectively combines land-use information with pipeline data to give practical suggestions for pipeline modification and land-use optimization to combat urban floods.Therefore,this methodology warrants further promotion in the field of urban re-planning.
基金financially supported by the National Natural Science Foundation of China (51741908)
文摘Developing effective irrigation and drainage strategies to improve the quality of saline-alkali soil is vital for enhancing agricultural production and increasing economic returns. In this study, we explored how irrigation and drainage modes (flood irrigation, drip irrigation, and sub-surface pipe drainage under drip irrigation) improve the saline-alkali soil in Xinjiang, China. We aimed to study the transport characteristics of soil water and salt under different irrigation and drainage modes, and analyze the effects of the combination of irrigation and drainage on soil salt leaching, as well as its impacts on the growth of oil sunflower. Our results show that sub-surface pipe drainage under drip irrigation significantly reduced the soil salt content and soil water content at the 0–200 cm soil depth. Under sub-surface pipe drainage combined with drip irrigation, the mean soil salt content was reduced to below 10 g/kg after the second irrigation, and the soil salt content decreased as sub-surface pipe distance decreased. The mean soil salt content of flood irrigation exceeded 25 g/kg, and the mean soil desalination efficiency was 3.28%, which was lower than that of drip irrigation. The mean soil desalination rate under drip irrigation and sub-surface pipe drainage under drip irrigation was 19.30% and 58.12%, respectively. After sub-surface drainage regulation under drip irrigation, the germination percentage of oil sunflower seedlings was increased to more than 50%, which further confirmed that combined drip irrigation and sub-surface pipe drainage is very effective in improving the quality of saline-alkali soil and increasing the productivity of agricultural crops.
文摘Due to the frequent leakage of pipes and valves in the current water supply and drainage system engineering, water resources are wasted and the overall engineering quality is poor. The design of water supply and drainage system for green buildings is studied. Obtain the water supply and drainage volume and design the maximum daily water consumption. Select water supply and drainage mode, and use frequency conversion water supply and shunt system to realize water supply and drainage of buildings. Water supply and drainage equipment and pipes are selected to ensure construction quality. Water supply and drainage design model is built based on BIM, and pipeline space is reserved. Arrange and lay water supply and drainage pipelines to complete the design of water supply and drainage system for engineering buildings. Through the demonstration and analysis of examples, the system effectively reduces the sewage discharge and tap water consumption, has good energy-saving effect, and generally meets the requirements of two stars for green buildings, which proves the reliability of the system.
文摘Many dangerous effects arise from seepage through earth dams based on pervious layer. Therefore, the dam embankment must be provided with seepage control measures to avoid such effects. In the present work, different control methods were used such as flat slopes, toe drainage systems, and a catch drain in the tail water. The hydraulic performance of each control measure was evaluated using the analytical solutions, previously developed, to estimate the seepage quantity (q), the height of seepage surface (h<sub>3</sub>), and the coordinates of the free surface (h<sub>x</sub>). Study was conducted on a physical model for a dam embankment having a top width (b) = 10.0 meter, height (H<sub>d</sub>) = 30.0 meter, and slope factor (m) = 1.5. The obtained results were analyzed and presented in dimensionless charts. Results showed that, the used control measures possess a great effect on the characteristics of seepage through earth dams based on pervious foundations. A comparative study was conducted between the studied toe drainage systems to enable the designers the better choice for design purposes.
基金supported by the National Natural Science Foundation of China.(Grant No:59679028)
文摘In order to study the law of nitrogen leaching losses from the paddy field under the condition of drainage, based on the theories of potential energy and solute transport, a water nitrogen dynamic mixed model by combining the flow net with dynamic method was established. In the computation of buried pipe drainage, the superposition principle was used to simplify the complex solving of the two dimensional problem about water nitrogen transportation in Soil Plant Air Continuous (SPAC) system into several one dimensional problems. The presented method is simple and practical. Some field experiments were carried out to demonstrate the validity of the model.
基金This work was financially supported by the National Natural Science Foundation of China(Grant No.51790533,No.41361071,No.51669029).
文摘This study addressed the problem of low drainage efficiency or even no drainage in subsurface drainage systems buried in saturated-unsaturated zones above the water table.An indoor experiment on infiltration under ponded conditions in a homogeneous soil column was performed to study the effects of soil texture on the soil wetting front morphology,soil infiltration rate,drainage efficiency of the subsurface drainage pipe,vertical distribution of soil water content and salinity along the soil column.The results showed that the drainage process of subsurface drainage pipes above the water table was quite different from that of subsurface drainage pipes below the water table.When a subsurface drainage pipe was located in sandy soil,the migration of soil water toward the bottom of the drainage pipe was significant,and the water could not be discharged into the pipe.When the drainage pipe was located in loamy clay,the movement of soil water towards the bottom of the pipe was retarded,and the water could be discharged into the pipe.During the drainage process,the drainage of the pipe can produce nonequilibrium flow in the soil,and the continuity of the nonequilibrium flow can be affected by the hydraulic conductivity of the soil above the pipe,which can result in discontinuous drainage and low drainage efficiency.The water holding capacity,permeability and aeration of soil are important factors that affect the drainage under unsaturated conditions.Eliminating the hysteresis effect and capillary barrier around the drainage pipe and adjusting water holding capacity,the permeability and aeration of soil structure through a new subsurface drainage structure may enhance the drainage efficiency of subsurface drainage pipes in saturated-unsaturated zones.
基金supported by the Funds for the Anhui Provincial Science and Technology Innovation Strategy and Soft Science Research Project(Grant Number 202206f01050017)National Natural Science Foundation of China(Grant Number 72131006,6201101347,72071063)+3 种基金Fundamental Research Funds for the Central Universities(Grant Number JS2021ZSPY0037)Research Project of China Three Gorges Corporation(Grant Number 202103355)Yangtze Ecology and Environment Co.,Ltd.(Grant Number HB/AH2021039)Power China Huadong Engineering Corporation Limited(KY2019-ZD-03).
文摘Urban drainage pipe network is the backbone of urban drainage,flood control and water pollution prevention,and is also an essential symbol to measure the level of urban modernization.A large number of underground drainage pipe networks in aged urban areas have been laid for a long time and have reached or practically reached the service age.The repair of drainage pipe networks has attracted extensive attention from all walks of life.Since the Ministry of ecological environment and the national development and Reform Commission jointly issued the action plan for the Yangtze River Protection and restoration in 2019,various provinces in the Yangtze River Basin,such as Anhui,Jiangxi and Hunan,have extensively carried out PPp projects for urban pipeline restoration,in order to improve the quality and efficiency of sewage treatment.Based on the management practice of urban pipe network restoration project in Wuhu City,Anhui Province,this paper analyzes the problems of lengthy construction period and repeated operation caused by the mismatch between the design schedule of the restoration scheme and the construction schedule of the pipe network restoration in the existing project management mode,and proposes a model of urban drainage pipe network restoration scheme selection based on the improved support vector machine.The validity and feasibility of the model are analyzed and verified by collecting the data in the project practice.The research results show that the model has a favorable effect on the selection of urban drainage pipeline restoration schemes,and its accuracy can reach 90%.The research results can provide method guidance and technical support for the rapid decision-making of urban drainage pipeline restoration projects.
