TY - JOUR
ID - 22528
TI - Overflow and underflow within the broad-crested gabion weir in free flow with sand bed conditions
JO - Sharif Journal of Civil Engineering
JA - J30
LA - en
SN - 2676-4768
AU - Salehi, S.
AU - Esmaili, S.A.
AU - Sadeghi namaghi, N.
AU - Esmaili, K.
AD - Dept. of Water Sciences and Engineering Ferdowsi University of Mashhad
AD - Dept. of Water Sciences and Engineering Water Structures
Bu-Ali Sina University, Hamedan
Y1 - 2022
PY - 2022
VL - 37.2
IS - 4.2
SP - 3
EP - 13
KW - Gabion weir
KW - Flow classification
KW - Discharge coefficient
KW - Free flow
KW - Overflow
KW - Under flow
DO - 10.24200/j30.2021.57425.2907
N2 - In order to calculate and predict the discharge flow through and over the gabion weir, 33 experimental broad-crested gabion models were carried out through the sand bed condition. The flow conditions through and over the gabion were presented as three classifications which involved partial flow conditions through a gabion, fully gabion flow through a gabion weir, and overflow on a gabion weir. These classifications were considered due to the free flow conditions. Based on the partial and fully gabion flows, an equation was proposed to calculate the gabion flow. Moreover, the flow discharge over the gabion was considered based on the broad-crested weir formula and then, the coefficient discharge of broad-crested gabion weir was proposed based on experimental measurements. Comparison between the proposed values and experimental measurements illustrates that good agreement is between the proposed and experimental flow discharges. Also, the investigation of flow variations through the gabion showed that the error of gabion equation increased significantly due to overflowing on gabion weir. In order to raise the accuracy of the calculation process of flow discharge through the gabion an equation was proposed based on the geometry and Darcy Wisbech’s parameters. The porosity, length, and particle size were defined based on Darcy Wisbech equations. Some math indexes were considered for this equation and by employing the Mathematical software, these parameters were presented based on the non-liner technique. The error was measured based on the experimental and proposed values and the result of the comparison pointed to the suitable agreement between the two groups of values. Finally, the maximum scour hole was measured by point-gauge along the longitudinal section. Based on threshold velocity and geometrical and hydraulic parameters, an equation was proposed to predict the maximum scour hole depth at the downstream of the broad-crested gabion weir.
UR - https://sjce.journals.sharif.edu/article_22528.html
L1 - https://sjce.journals.sharif.edu/article_22528_54afd5baaaf9d7f744cc35bed70270e7.pdf
ER -