Rational calculation of stilling basin

1. The number of steel bars needed to be configured has a great relationship with the stress of concrete members
the stress should be calculated first, and then the number of reinforcement should be calculated according to the regulations issued by the state
how to calculate? You can search the keywords of "reinforcement calculation of reinforced concrete structure" on the Internet to find the design rules, design tutorials, and design methods

2. Calculated value = - 7.255 & lt= 110.000(kPa)

3. The purpose of building a sluice on the river is to intercept the water from the upstream and raise the water level for diversion irrigation and water supply
when there is a flood in the upstream, it is necessary to open the sluice to discharge the flood. In order to ensure the safety of flood discharge, when the water level difference between the upstream and downstream is small (such as 0.03m), it is still necessary to discharge a certain amount of flow safely, so the corresponding total clear width of the sluice is required
because the head difference will affect the size of the gate flow, which will also affect the scale of the project. During the impoundment period, the water level difference between the upstream and downstream is often very large, while when the sluice is opened (from the discharge form, it is the transition from orifice flow to weir flow), the water level of the downstream will rise slowly, that is, the water level difference between the upstream and downstream has a narrowing process. In this process, energy dissipation is also changing. In the initial discharge, the downstream water level is generally low, and the energy dissipation problem is relatively prominent; With the rise of the downstream water level, the submergence degree of the hydraulic jump will increase, and the energy dissipation conditions will be improved
in calculating the working hours of energy dissipation, several discharge volumes can be used to calculate the water depth after the jump respectively, and then compared with the downstream water depth, and the discharge corresponding to the most unfavorable situation can be selected as the design discharge to determine the depth of stilling basin. The design flow for determining the length of stilling basin is not necessarily the same as that for determining the depth, but also needs to be determined by corresponding combination
in principle, the downstream water depth should be determined according to the relationship curve between water level and discharge (which can be calculated according to the measured data or the open discharge uniform flow), but in the actual engineering design, the situation is often not simple, especially for small sluice
the upstream water level is relatively easy to determine, because there will be a normal water level in the design, in addition, there may be the highest water level, limited water level, etc., so the key depends on the selection of the downstream water level, but there is no completely universal method
therefore, several characteristic water levels can be selected according to the current situation of the river and the actual application requirements (generally unsafe, sometimes it is assumed that there is no water in the downstream), and then combined with the characteristic water level in the upstream to calculate the parameters of the energy dissipator.

4. When there is a flood in the upstream, it is necessary to open the sluice to discharge the flood. In order to ensure the safety of flood discharge, when the water level difference between the upstream and downstream is small (such as 0.0.3m), it is still necessary to safely discharge a certain amount of flow, so the total net width of the corresponding sluice hole is needed, During the period of impoundment, the water level difference between the upstream and downstream is often very large. However, when the sluice is opened (from the form of discharge, it is the transition from orifice flow to weir flow), the downstream water level will rise slowly, that is, the water level difference between the upstream and downstream has a process of narrowing. In this process, the energy dissipation situation is constantly changing. In the initial discharge, the downstream water level is generally low, At this time, the problem of energy dissipation is relatively prominent; With the rise of the downstream water level, the submergence degree of the hydraulic jump will increase, and the energy dissipation conditions will be improved, Then, the flow corresponding to the most unfavorable situation is selected as the design flow for determining the depth of stilling basin. The design flow for determining the length of stilling basin is not necessarily the same as that for determining the depth, and it needs to be determined by corresponding combination. In principle, the downstream water depth should be determined according to the relationship curve between water level and flow (which can be calculated according to the measured data or the open discharge uniform flow), However, in practical engineering design, the situation is often not simple, especially for small sluices. The upstream water level is relatively easy to determine, because there will be a normal water level in the design, in addition, there may be a maximum water level, limited water level, etc., so the key depends on the selection of downstream water level, but there is no completely universal method, According to the current situation of the river and the actual application requirements, several characteristic water levels can be selected (generally unsafe, sometimes it is assumed that there is no water in the downstream), and then combined with the characteristic water level in the upstream to calculate the parameters of the energy dissipator

5. The number of steel bars needed to be configured has a great relationship with the stress of concrete members
the stress should be calculated first, and then the number of reinforcement should be calculated according to the regulations issued by the state
how to calculate? You can search the key words of "reinforcement calculation of reinforced concrete structure" on the Internet to find design rules, design tutorials, and design software

6. The pressure at a certain depth in the water is p= ρ Hg=1 × 10³ kg/m³ × H × 9.8N/kg=9.8 × 10³ × HPa/m³ Where h is the water depth; Pressure f = P × S (stressed area)

7. Through calculation and comparison, this paper analyzes the influence of downstream water depth on the calculation of stilling basin depth, and discusses how to consider the lag of downstream water level rise in the calculation of sluice stilling basin. The results show that if the downstream water depth is not properly selected in the calculation
let's see what others say.

8. It can be calculated by referring to the formula: py = YW * (H + H) * a
py: uplift pressure on the floor (KN)
YW: volume weight of water (KN / M & # 179;)
H: downstream water depth (m)
H: floor thickness (m)
A: floor area (M2)

9. The height of the wing wall on the side of the stilling basin can be set as the maximum water depth after the downstream jump when discharging, and then the superelevation can be added.
the filling on the top of the wing wall is treated with masonry revetment instead of setting the top elevation of the wing wall directly to the elevation of the check flood level
the following calculation method is for reference only< (1) determination of stilling basin depth: S = SHC - h t - d z
through calculation, the stilling basin depth is XXM, and the design is XXM

(2) calculation of stilling basin length:
LK = BL J
LJ = XX (fr1-1) (FR1 < XX)
where LK is stilling basin length (m)
b - hydraulic jump length correction coefficient, x ~ x can be used
LJ - hydraulic jump length (m)
through calculation, the length of stilling basin is XXM, and the design is XXM

(3) the calculation of the height of the side wall of the stilling basin: the downstream maximum conjugate water depth HC = XX & quot; According to the engineering design standard, the super height of the side wall of the stilling basin is taken as XXM, so the height of the side wall of the stilling basin calculated from the bottom plate of the stilling basin is (XX + XX) M

X represents the value you want to calculate, or the existing data value!