In order to study the engineering behaviors of reinforced gabion retaining wall,laboratory model test was carried out.Cyclic load and unload of five levels(0-50,0-100,0-50,0-200 and 0-250 kPa) were imposed.Vertical ea...In order to study the engineering behaviors of reinforced gabion retaining wall,laboratory model test was carried out.Cyclic load and unload of five levels(0-50,0-100,0-50,0-200 and 0-250 kPa) were imposed.Vertical earth pressure,lateral earth pressure,deformation behaviors of reinforcements,potential failure surface and deformation behaviors of wall face were studied.Results show that vertical earth pressure is less than theoretical value,the ratio of vertical earth pressure to theoretical value increases nearly linearly with increasing load,and the correlation coefficient of regression equation is 0.92 for the second layer and 0.79 for the fifth layer.The distribution of lateral earth pressure along the wall back is nonlinear and it is less than theoretical value especially when the load imposed at the top of retaining wall is large.Therefore,reinforced gabion retaining wall will be in great safety when current method is adopted.The deformation behaviors of reinforcements both in the third layer and the fifth layer are single-peak distributions,and the position of the maximum strain is behind that determined by 0.3H(Here H refers to the height of retaining wall) method or Rankine theory.Lateral deformation of wall face increases with increasing load,and the largest lateral deformation occurs in the fourth layer,which lead to a bulging in the middle of wall face.展开更多
Over recent years, there has been a clear increase in the frequency of reported flooding events around the world. Gabion structures offer one means of flood mitigation in dam spillways. These types of structures provi...Over recent years, there has been a clear increase in the frequency of reported flooding events around the world. Gabion structures offer one means of flood mitigation in dam spillways. These types of structures provide an additional challenge to the computational modeller in that flow through the porous gabions must be simulated. We have used a computational model to investigate the flow over gabion stepped spillways. The model was first validated against published experimental results. Then, gabion stepped spillways with four different step geometries were tested under the same conditions in order to facilitate inter-comparisons and to choose the best option in terms of energy dissipation. The results show that normal gabion steps can dissipate more energy than overlap, inclined, and pooled steps. An intensive set of tests with varying slope, stone size, and porosity were undertaken. The location of the inception point and the water depth at this point obtained from this study were compared with those from existing formulae. Two new empirical equations have been derived, on the basis of a regression analysis, to provide improved results for gabion stepped spillways.展开更多
Gabions are wire baskets filled with rocks and play a critical role in various civil engineering applications.These include roadside stabilization,riverbank protection,erosion control in gullies,dams,reservoirs,and fo...Gabions are wire baskets filled with rocks and play a critical role in various civil engineering applications.These include roadside stabilization,riverbank protection,erosion control in gullies,dams,reservoirs,and foundational support for structures.However,despite their importance,scientific research on gabion technology,particularly in developing countries like Nepal,remains limited.Key challenges include the durability and stability of gabion structures under adverse conditions.To address these gaps,the authors conducted laboratory experiments and field investigations along the Khar Khola River in Gorkha,Nepal.The laboratory experiments compared the performance of Japanese-style gabions and hybrid structures combining Japanese and Nepalese elements,both with and without geotextiles.Meanwhile,field investigations focused on evaluating gabion stability by measuring horizontal deformation.The findings revealed that constructed gabion revetments demonstrated negligible deformation across different designs,signifying high structural stability.However,ensuring long-term effectiveness requires careful installation of base foundations and launching aprons,especially after flooding events,which can destabilize soft foundations and cause bed scouring.The hybrid gabion,blending Japanese and Nepali techniques,emerged as a particularly effective alternative.This design demonstrated improved resilience and stability,retaining its structural integrity even after two years of exposure to flooding and environmental stressors,making it an adaptable and cost-efficient solution for developing regions.展开更多
为深入了解钢筋石笼在弯道渠首引水工程中的过流规律,选用流体体积(volume of fluid,VOF)法、多孔介质模型对钢筋石笼进行数值模拟,并对数值模型进行物理试验验证。研究得到不同孔隙率、水深、长度、高度等参数对钢筋石笼流速分布、过...为深入了解钢筋石笼在弯道渠首引水工程中的过流规律,选用流体体积(volume of fluid,VOF)法、多孔介质模型对钢筋石笼进行数值模拟,并对数值模型进行物理试验验证。研究得到不同孔隙率、水深、长度、高度等参数对钢筋石笼流速分布、过流规律的影响,并采用SPSS软件对所得数据拟合得到钢筋石笼流量公式、堰前水深公式。结果表明:钢筋石笼内部流量随着孔隙率、高度的增大而增大,但会受到水流回流的影响;钢筋石笼周围的绕流程度随着远端水深的增大而增大;钢筋石笼长度、远端水深及高度不宜过大;钢筋石笼综合流量系数与孔隙率n、钢筋石笼高度和钢筋石笼上游0.8 m处水头之比P/H0、钢筋石笼长度和钢筋石笼上游0.8 m处水头之比l/H0的关系较为显著,所得钢筋石笼流量计算公式的最大相对误差不超过5.0%,精度较高,可为引水总量的率定提供参考;得到的堰前水深公式精度较高,决定系数为0.966。研究可为钢筋石笼在引水工程上的应用提供参考和依据。展开更多
基金Project(50778180) supported by the National Natural Science Foundation of ChinaProject(CX2010B049) supported by Hunan Provincial Innovation Foundation for Postgraduate,China
文摘In order to study the engineering behaviors of reinforced gabion retaining wall,laboratory model test was carried out.Cyclic load and unload of five levels(0-50,0-100,0-50,0-200 and 0-250 kPa) were imposed.Vertical earth pressure,lateral earth pressure,deformation behaviors of reinforcements,potential failure surface and deformation behaviors of wall face were studied.Results show that vertical earth pressure is less than theoretical value,the ratio of vertical earth pressure to theoretical value increases nearly linearly with increasing load,and the correlation coefficient of regression equation is 0.92 for the second layer and 0.79 for the fifth layer.The distribution of lateral earth pressure along the wall back is nonlinear and it is less than theoretical value especially when the load imposed at the top of retaining wall is large.Therefore,reinforced gabion retaining wall will be in great safety when current method is adopted.The deformation behaviors of reinforcements both in the third layer and the fifth layer are single-peak distributions,and the position of the maximum strain is behind that determined by 0.3H(Here H refers to the height of retaining wall) method or Rankine theory.Lateral deformation of wall face increases with increasing load,and the largest lateral deformation occurs in the fourth layer,which lead to a bulging in the middle of wall face.
基金supported by the Higher Committee for Education Development(HCED)in Iraq
文摘Over recent years, there has been a clear increase in the frequency of reported flooding events around the world. Gabion structures offer one means of flood mitigation in dam spillways. These types of structures provide an additional challenge to the computational modeller in that flow through the porous gabions must be simulated. We have used a computational model to investigate the flow over gabion stepped spillways. The model was first validated against published experimental results. Then, gabion stepped spillways with four different step geometries were tested under the same conditions in order to facilitate inter-comparisons and to choose the best option in terms of energy dissipation. The results show that normal gabion steps can dissipate more energy than overlap, inclined, and pooled steps. An intensive set of tests with varying slope, stone size, and porosity were undertaken. The location of the inception point and the water depth at this point obtained from this study were compared with those from existing formulae. Two new empirical equations have been derived, on the basis of a regression analysis, to provide improved results for gabion stepped spillways.
文摘Gabions are wire baskets filled with rocks and play a critical role in various civil engineering applications.These include roadside stabilization,riverbank protection,erosion control in gullies,dams,reservoirs,and foundational support for structures.However,despite their importance,scientific research on gabion technology,particularly in developing countries like Nepal,remains limited.Key challenges include the durability and stability of gabion structures under adverse conditions.To address these gaps,the authors conducted laboratory experiments and field investigations along the Khar Khola River in Gorkha,Nepal.The laboratory experiments compared the performance of Japanese-style gabions and hybrid structures combining Japanese and Nepalese elements,both with and without geotextiles.Meanwhile,field investigations focused on evaluating gabion stability by measuring horizontal deformation.The findings revealed that constructed gabion revetments demonstrated negligible deformation across different designs,signifying high structural stability.However,ensuring long-term effectiveness requires careful installation of base foundations and launching aprons,especially after flooding events,which can destabilize soft foundations and cause bed scouring.The hybrid gabion,blending Japanese and Nepali techniques,emerged as a particularly effective alternative.This design demonstrated improved resilience and stability,retaining its structural integrity even after two years of exposure to flooding and environmental stressors,making it an adaptable and cost-efficient solution for developing regions.
文摘为深入了解钢筋石笼在弯道渠首引水工程中的过流规律,选用流体体积(volume of fluid,VOF)法、多孔介质模型对钢筋石笼进行数值模拟,并对数值模型进行物理试验验证。研究得到不同孔隙率、水深、长度、高度等参数对钢筋石笼流速分布、过流规律的影响,并采用SPSS软件对所得数据拟合得到钢筋石笼流量公式、堰前水深公式。结果表明:钢筋石笼内部流量随着孔隙率、高度的增大而增大,但会受到水流回流的影响;钢筋石笼周围的绕流程度随着远端水深的增大而增大;钢筋石笼长度、远端水深及高度不宜过大;钢筋石笼综合流量系数与孔隙率n、钢筋石笼高度和钢筋石笼上游0.8 m处水头之比P/H0、钢筋石笼长度和钢筋石笼上游0.8 m处水头之比l/H0的关系较为显著,所得钢筋石笼流量计算公式的最大相对误差不超过5.0%,精度较高,可为引水总量的率定提供参考;得到的堰前水深公式精度较高,决定系数为0.966。研究可为钢筋石笼在引水工程上的应用提供参考和依据。
