Abstract
flood is always one of the most hazardous natural phenomenon that occurs every year around the world. One of the basic methods for controlling the Stream is construction of a levee. The levee strength is important due to the materials used in the construction of and the lack of protective coating on it. The main purpose of this research is to investigate the effect of Rip-Rap on the failure mechanism and transverse and deep erosion of levees. The levees in this experiments, were made of two uniform soil samples, using a non-cohesive soil sample of 1.7 mm in diameter and a cohesive soil sample of 1.8 mm in diameter. Also, three types of rip-rap of medium size 1, 2 and 3 cm were used to cover. Geometric features of the levee include: the length of the bottom 1.35 m, the height 0.25 m, the length of the crest 0.1 m, the slope of the framework on both sides 1:2.5 and 0.35 wide. In the crest of the levee a breach of 10 cm and a depth of 3 cm was created to control the flow. The inlet discharges to the flume were constant and considered equal to 1.4, 2 and 2.6 liters per second. The fracture of levees in this study has been due to overflow. Based on the results, it was found that the average diameter of the Rip-Raps is directly related to the transverse erosion of the levee’s breach, so that the larger the Rip-Rap diameter, the more and greater is the transverse erosion. The levees with Rip-Rap, pass more discharges over themselves and have a longer fracture time than the levees without Rip-Rap. A cohesive levee with 15% clay has a very good resistance. In a discharge of 1.4 liters per second, with a 2 and 3 cm rip-Rap, this levee has no erosion and this shows a high resistance. The erosion in the cohesive sample and without the rip-rap starts from the toe part and, with deep erosion, destruction moves backward to the upstream. In addition, the dimensionless parameters of the research were extracted and discussed in detail.

 

In recent years, the use of baffle sloped culvert as energy disspation, and fish passed fish has boomed. This study tests, done in a steep flume with the floor width of 25cm, which the W shaped spillway attached in about 5 meter from the flume with varriables, the distance between barriers, variable slope from 3 to 7.6 perecent in different discharge was scheduled. In this study, considering to hydraulic performance of asymmetric w shape overflow, it was decided that to investigate the hydraulic performance of culvert, this structure will use as a barrier in open Calvert. In the present study, asymmetrical W shaped Weir are designed with the tip angle of 40 °, and the barriers with 30°, 60°, are designed with the tip angle of 90°. To recognize the hydraulic performance of fish-path, three physical model was designed for any barrier, that including: 30 barriers of asymmetrical W shaped Weir with 0.6 relative distance, a model with 15 barriers with 1.2 relative distance, and 10 barriers with 1.8 relative distance. Based on the obtained results of increasing slope, flow discharge, relative distance, reducing roughness coefficients 0f barriers height, and dissipation energy dissipation will reduce. To perform this research after the installation of obstacles at the relative distances, the discharge and tilt are adjusted. After the stabilization of the flow, the flow profile of the surface of the water was rolled out, as well as the slope of 4.8% and the rate of 32.68 liters per second and the w overflow An asymmetric pattern with angles of 40 degrees between the first and second barriers, six, seven, twelve, thirteen, eighteen and nineteen in five transverse points and three longitudinal points of the velocity profile were taken by microluminescence. After analyzing the velocity profiles along the rough surface, it was found that, as the flow downward and the effect of the roughness decreases, the velocity profile becomes thicker and occurs at a lower depth than the flow current level of the maximum flow velocity Gives. Also the W spillway asymmetrical shapshape has two apex angle of 40 degrees and the relative distance of 0/6 the relative distance and relative distance of 1/2 Culverts to reduce erosion of the relative distance to the upstream migration is the fishes. discharge down there on the slope of a motivating factor to attract numerous Fish¬way input but high discharge Fish¬way climb gradient reduction is made to flow upstream.

The hydraulic jump is one of the applicable phenomenons in energy dissipation of rapid flows. The hydraulic jump is one of the rapid varied flows that with converting from the super-critical state of flow to the sub-critical state in a short distance results in sensible energy dissipation and increase of the flow depth. In this research, the characteristics of the hydraulic jump are assessed by conducting an experimental study on the bed with attached floating objects as energy dissipators in stilling basin for the first time. To this end, a set of sphere objects with different density, bearing length and diameters are attached with flexibility to the bed of stilling basin. Considering that the attached floating objects, for the first time, are considered as energy dissipators in stilling basin, the goal of this study is to investigate the sphere objects bearing length, density and diameter effect on the characteristics of the hydraulic jump and finally comparing the obtained results with other related work. In this study, sixty experiments with Froude number from 5.1-8.3 are performed. The floating objects with three different diameters 4 cm, 5 cm, and 7 cm, five bearing lengths 0 cm, 1.5 cm, 2.5 cm, 3.5 cm, and 4.5 cm, and five densities 0.12 gr/cm3, 0.255 gr/cm3, 0.4 gr/cm3 , 0.54 gr/cm3, and 0.836 gr/cm3 are used. The results show that the length of hydraulic jump, rolling length, and secondary depth in average were decreased, respectively, 39.3%, 53.9%, and 21% by using the bed with attached floating objects in comparison to the classic bed and the energy dissipation is increased in average with 11%. The floating objects with shorter bearing length are more effective on the characteristics of the hydraulic jump with Froude number between 7.5-8.3. However, with decreasing the Froude number the floating objects with longer bearing length are more effective on these characteristics. With increasing the diameter the effect of floating objects on the characteristics of the hydraulic jump is decreased which is more observable with Froude number between 6.2-8.3. With increasing the density of objects up to 0/4 gr/cm3 the effect of floating objects on the characteristics of the hydraulic jump is increased. But, with increasing the density of objects up 0/836 gr/cm3 the effect of floating objects on the characteristics of the hydraulic jump is decreased.

While the flow of pollutants discharged to the extremely shallow water ambient, condition of acceptor have a significant effect on the diffusion of pollution. In this study, some environmental, geometrical and hydraulic conditions of surface jets flow in extremely shallow water were investigated. For the purposes of this study, a experimental model of surface draining in extremely shallow water was set up and experiments was carried in flume with 3.2 meters length, 0.6 meters width and 0.9 height. Accordingly, experiments were programed by taking three simple ports with 1.2, 1.6, and 2.2 cm diameter, The concentrate flow with of 20, 40 and 60 g/L concentration in a acceptor ambient with H/d = 2. The results showed that equilibrium length was extremely decreased by increasing concentrations, as for three times increasing the concentration from 20 to 60 g/L, equilibrium length decreased from 25 to 10. However, on the basis of the results, it was showed that the effect of relative viscosity changing is significant, as its effect is high in all concentrations to 100, and then the amount of Cm/C0 tends to constant. In this regard, the effect of surface tension changing on passed relative length was investigated and results showed that, this parameter always is effective in extremely shallow acceptor at all stages from the beginning to the end of the Progress. Consequently, it has constant slope and surface tension has effect on flow diffusion with clear trend in all concentrations. With a relative fixed trend at all concentrations in surface tension parameter influences to diffusive process with a clear trend. In fact, surface tension in all concentrations achieve to 5 after equilibrium length and jet energy dissipation area. On the other hand, velocity changing of jet flow central line in extremely shallow acceptor was carried out based on dimensionless effective parameters. It was also found that the maximum length of the jet distribution point is related to the homogeneous fluid and the temperature difference of ± 5 ° and ± 10 °, reduce the jet distribution point by 12% and 20% respectively.

Levee failure due to water overtopping is a common phenomenon at flood times which brings large financial, human and environmental losses. Hence, this study is trying to investigate the failure mechanism of levees and the factors affecting it. Thus, four non-adhesive soil samples with the average diameter of ( 0.44, 0.7, 1.7 and 2.4 mm and four adhesive soil samples with the average diameter of 0.2, 0.5, 1.1 and a.7 mm were used to build levees. Geometrical characteristics of Levee is equal to 1.35 for bed width, 0.25m height, 0.1 m crest width, 0.35 m width with a 1:2.5 ramps slope. Inflow discharges were constant and equal to 0.85, 1.4 and 2 L/s. results indicated that in models with the average diameters of 0.44 and 0.7 mm, the transverse changes in the formed gap is stepped while in models with 1.7 and 2.4 mm average diameter, transverse erosion was more intense. In addition, the discharge crosses the gap, changes rapidly and the failure time is determined as the time in which the crossing discharge reaches the maximum content. Results also showed that increasing the average diameter of particles decreases the failure time while the crossing discharge increases. Also, in adhesive models, the sample with 15% of silt and clay has a larger resistance to erosion in comparison with other investigated samples. Erosion in adhesive models occurs first in the toe and acts like a retrograde erosion which moves backward. Finally, the non-dimensional parameters were elicited and discussed in details.

Retaining wall design process is based on extreme forces applied by failure wedge of levee, wall- levee generated action and reaction and the external forces. Thus, it is important to investigate the affecting parameters on failure wedge of cantilever walls. In this study, geometrical parameters of failure wedge are investigated including Length parameter (L), height parameter(h) and the failure angle ( ).The effect of stratification, drained and undrained conditions on geometrical parameters of failure wedge and design parameters were investigated through columbus and elastoplastic graphical wedge method by conducting 20 laboratory experiments. Results indicated that, in drained condition, the deep development of failure wedge behind the rough wall is almost 30 percent higher than that of smooth wall. Also, increasing the roughness of the wall, reduces the general failure angle of heterogeneous levees up to 10.4%. an average difference of 28% between experimental results and theoretical equations proves the conservative design of walls based on such equations. The absence of failure wedge at the wall toe-contrary to theoretical equations-and the average 32.75% and 29.25% reduction in experimental applied forces to wall in comparison with theoretical data, are evidences for the conservative design of walls based on theoretical equations.

 

 

Design of retaining wall on the forces applied in part by the wedge created between the wall and backfill embankment and action and reaction and external loads carried. From this perspective, the parameters affecting on the failure wedge is important. Therefore, in this study, To check of The wedge geometry parameters including length parameter , Height parameter and failure line Investigated and Finally, the design parameters of force and Force point are Investigated. Laboratory observations in physical models and Hydraulic Engineering Department of Water Sciences at the University of Chamran was done. Tests planned for this research was established that the effect of density changes, wall roughness, texture changes and internal friction angle the backfill and loading due to the rough wall In 21 tests on the geometry of the wedge and design parameters set forth by way of Coulomb, wedge and elastic graphical soil arching method were compared. The investigation results showed that length parameter, Height parameter and failure line in , 20 percent reduction in the length and height parameters increased 20 percent compared with the wedge angle of the line failure theory ocuured, And in Decreased 50%, 70% and 20% increase in the angle of refraction, respectively. Parameter length, height and angle failure surface of texture changes and internal friction angle, respectively 70,60 percent and 10 percent increase over the wedge theory showed. Wall roughness parameters and parameter changes according to the length wedge Elevation 5 percent and 5 percent increase over the wedge angle failure surface of a showed theory. The loading on the rough wall in length parameters 5 percent decrease And the height and the angle of refraction parameters were respectively 20 and 10 percent (increase) compared with the wedge theory showed. Finally Parameter variations force and force point Due to changes of parameters expressed wedge geometry of the analytical methods Coulomb, wedge and elastoplastic graphical arching approach was expressed as a graph.

 

Flip buckets are commonly used to discharge flow away from a hydraulic structure when energy has to be dissipated for a flow velocity larger than about 20 m/s. important researches have done on new type of flip buckets that are triangular in longitudinal section. One method to increase efficiency of energy dissipation in the flip bucket spillway is installation of deflector. That is why, effect of triangular flip bucket and deflector were considered. The aim of this study is, numerical simulation of water flow through an triangular flip bucket and properties of jet terajectory, energy dissipation and other parameters by using Flow-3D software. In addition to the simulation without deflector, the deflector with angles of 27, 32 and 40 degrees, and two widths, 6 and 9 cm, were used along with flip buckets. All models in different discharges using RNG-K-ε turbulence model was run. On the other hand using the experimental results, simulation results were compared. results shown that both the physical models and numerical models with increasing the Froude number the ratio length of trajectory increases, The average error of numerical models for the upper limit of trajectory of the projectile 5.36 and lower limit of trajectory 5.32 percent respectively. With the deflector in the physical model 6 types of trajectory, but in the numerical models only 4 types of trajectory detectable. With the deflector, the amount of energy dissipation in the physical model compared to control tests Increased by 27% and increase in the numerical model is 26%. Comparing the results of numerical and physical models observed that the minimum error in Forud numbers high (low discharge) occurred. According to the results of the numerical model and compared with experimental data was observed that use of numerical models suitable alternative to physical models. After verify the numerical model was to develop numerical models. And other shapes of aerodynamic deflector was designed And by their presence was conducted simulation So deflector half circle, wing deflector and deflector triangular-shaped deflector with the difference that instead of the head, the base was placed in the direction of flow, be taken into consideration. Also deflector with angles that were not addressed in the physical model was studied

Morning-glory-type spillways comprise a circular inlet funnel, a 90 degree bend and an outlet tunnel. This spillway has three control sections that are at crest, throat and outlet which ought to be investigated. The presence of vortices can cause turbulences in inlet funnel of morning glory spillways and increase discharge coefficient and also the efficiency of the spillway.
The objective of the present investigation is to numerically model the flow through morning glory spillway and also investigate the effect of vortex breaking blades using Flow-3D. The numerical model used in the current research is the software in the field of fluid analysis (CFD), which has the capability of simulation of fluid on the free surfaces. In order to that, the flow has been simulated through the spillway with no blade as well as three, four and six blades with 15, 30, 45 and 50 degree situated blades. The software is used for all models with various discharges using RNG-K turbulence modeling.
The results are compared with experimental results. Results indicate that the number and arrangement of vortex breaking blades play an important role in decreasing the vortex intensity and increasing the discharge coefficient that leads to increase the efficiency of the spillway.
Among three different arrangements that have been investigated, the arrangement of six vortex breaking blades which are situated in 50 degree segments on the crest of the spillway are the most effective one. This arrangement has the dominant impact on the water level.
By adding six vortex breaking blades on the crest of the spillway, discharge coefficient becomes 2.5 times greater than the spillway with no blades.
The results also indicate that in the throat of the spillway, the velocity becomes critical and the pressure fluctuates constantly.
The results show good agreement between experimental data and numerical modeling, so numerical modeling can be utilized to simulate flow through morning glory spillway and it is a proper alternative to physical models.
 

The experimental investigation of discharge dense flow by means of hydraulic jets is a important purposes of this research. Hence, the dilution of dense fluid in the shallow ambient water static and dynamic, cases, survived length of jet core and spreading coefficient, have been evaluated. The investigated parameters water included of depth, velocity of ambient water, discharge and concentration of surface dense jet. To investigate the relationship between these parameters in a physical model tests were performed in the hydraulic laboratory of Shahid Chamran University, The results showed that increasing water depth decreases the borders of the host environment and the dilution increases. Increasing the concentration of the fluid jet is reduced dilution during the advance. By increasing the flow velocity of the host environment, and with initially low dilution rate in the downstream direction, the dilution increases. The receptor fluid velocity cm / s 4 and at concentrations of 15, 30 and 60 grams per liter of dilution changes x / D =5, respectively 12.7, 11 and 9.1% , And x / D=20 , respectively, 81/4, 74/18 and 73%, respectively, while that for speed c 8 cm/s in the same concentrations, changes in the concentration of x / D =5 the order of 7, 6 and 5% of x / D=20, respectively, 82, 80/21 and 77/53 percent. Also relation to changes in variables were extracted with R2 is equal to 0.95. The results showed that the core progressive jet, landing at number directly proportional to the fluid density and viscosity of the fluid is denser than photos, as well as increasing the depth of the acceptor with the progressive increase in the jet core. This elongation is due to lower boundaries of the host environment . Obtained during the ongoing relationship with the jet core is 0.941. The results showed that the diffusion coefficient is a function of the concentration and depth of the host environment, such as rising concentrations in the deep acceptor diffusion coefficient increases, the other in a deep acceptor was found that increasing the number of condensed down to about 30 diffusion coefficient is reduced, then this factor is a constant value of about 0.1 desire. The results showed that shallow acceptor in the boundaries of motion for nonlinear quadratic equation develop In this case, the maximum diffusion coefficient equal to the minimum of 0.28 and 0.095 respectively. In the shallow
It was found that a relatively constant depth, with increasing Froude number density of about 52 to 120 times the value of the diffusion coefficient is reduced to 2.7. However, for a constant density Froude number, on average, by increasing the relative depth of 5 to 15 percent increase in the diffusion coefficient of about 16.5.
 

Surface hydraulic jet is a turbulent flow constantly is getting out of a source where it discharged as a tangent to the ambient flow borders and air fluid. On environmental discussions, water resources are at risk of getting into concentrated wastewater and drainage. So predicted concentration and pollution of water ambient is very important especially in near of source point. Hence in this research the plunge point (mixing length), Xp, the maximum length of upper boundary, Xmax, and maximum length of inferior boundary, Xmin, and finally centerline concentration have been investigated by variation of geometrical and hydraulic conditions. The experiments of this research were performed in the physical and hydraulic laboratory of Shahid Chamran University (SCU), of Ahwaz. The experiments were tested in three diameters of nuzzle, 5, 8 and 15 mm at contraction angles 15, 30, 60 and 90 degrees. In addition, the concentrations of jet fluid were 15, 30 and 60 g/L as a salt fluid. The results showed that the increasing of contraction angle of nuzzle has a significantly effect on plunge point (up to 41 percent) and jet flux development (40 and 45 percent for upper and inferior, respectively). With increasing concentrations of dense fluid of 15 to 60 g/L the mixing and final concentration of jet flux increase to initial concentration equal to 52 percent. The centerline concentration of jet flow increase 46 percent with changed of contraction angle 15 to 90 degrees. Findings showed that the development length of concentration profile decreases up to 25 percent with the increase in the concentration 15 to 60 g/L. Finally, the statistical relationships were derived as plunge point, maximum of upper and inferior limit length in jet trajectory and centerline concentration.

 Water distribution network is a hydraulic infrastructure which is in fact a part of the water supply system. The hydraulic analysis of this network is necessary criteria od design.The analysis software of hydraulic design in water distribution system has been developed because of complex solutions of nonlinear government equation. Hence, in this research Hammer software was used as analyzing of Freidon city water supply system. The first components of system were simulated using Hammer then the results were calibrated by measured data. However, system was analyzed in steady state and then water hammer phenomenon were investigated because of suddenly stopping pumps and using the parameters of reliability, resilience, vulnerability and sustainability in water distribution systems been investigated the different scenarios.The purposes of this research were a newer standpoint to analyze water hammer phenomenon in water supply system. In traditional method damages of water hammer were estimated due to maximum pressure in system while duration and time variation of pressure was neglected. This study quantify parameters of network performance can be assessed under the water hammer phenomenon. Hence, these information through the parameters of reliability, resilience, vulnerability and combine them (sustainability) placed in the hands of decision makers. In addition, in this study both uncertainty pipe roughness coefficient and water demand in nodes were investigated. Then the flexibility of network due to uncertainly parameters was evaluated by Monte Carlo Simulation method. The results showed that the sustainability parameters which already used in water resource management will be used to evaluate the efficiency of water networks. Parameters of reliability, resilience and vulnerability represent the frequency, duration and damage of occurrence of water hammer, respectively and sustainability parameter can be a combination of the three parameters mentioned. The increase reliability and resilience and decrease the vulnerability the sustainability parameter increases and efficiency of the distribution network will further and the risk of water hammer is reduced. Water hammer phenomenon in studied network by showed 4.83 percentage points had a sustainability parameter less than 1. The protective structures increased the sustainability parameter and this point was 1.11 percent. In addition, the efficiency and flexibility of network decreases because of increasing variation coefficient and consequently the uncertainty on the nodes demand and pipe roughness. Water hammer phenomenon and unsteady flow may averagely result in reduced 40 to 50 percent of network flexibility.

Due to coastal erosion or landslide slopes the floating logs and branches were entranced to the rivers where they will increase the flood power. These currents have serious problems such as increasing the water level upstream, decreasing both the cross-section area and discharge coefficient of spillways. In this research, the effect of trapping bodies have been investigated such as logs and branches of trees as an individual cumulative entrance to the overflows of piano key weirs (PKW). The piano key weirs have a discharge capacity more than other spillways in the low headwater so they have the potential absorption of floating refugees because of more efficiency. To achieve these purposes, the experiments of this research were performed on two piano key weirs 10 and 30 cm in height which these were placed on experimental flume with 12m length, 0.8m width and 0.7m height. On the weirs were installed the parapet walls with 2.5, 3.5 and 4.5cm height and the experiments were performed in both with and without parapet wall. Overall, the survey results showed that in both individual and cumulative tests, increasing the likelihood of blockage increases the level of upstream water level and discharge coefficient at a constant discharge. In individual experiments, the increasing of ratio of D/H increases the likelihood of blockage for all the logs and branches. However, the parapet wall partly increases the plugging. But the effect of increasing the diameter of the logs was more and more clear. In addition, likelihood of blockage and the volume of logs and branches trapped will be decreased due to increasing water level in the cumulative experiments in both weirs. Findings also showed that the parapet wall and logs and branches could increase H rather than Hr up to 1.5 times. In the 10cm spillway the likelihood blockage was 1.0 and but in the weir of 30 cm, due to turbulence caused by high energy flow, do not was to 1 and only close up to 1. Finally, the statistical relationships were presented as likelihood blockage at the tested spillways

The Piano keys weirs (PKW) are a special form of labyrinth weirs which was conducted by the Institute Hydrocoop in France. As has been shown in the previous studies piano key weirs have relatively high discharge capacity at low head. So that in high head, spillway efficiency is decreased due to submergence in the start of outlet key. Therefore, in this study, research was founded on piano key weir with parapet wall and without it. Experiments of this research were done in physical and hydraulically laboratory of Shahid Chamran University (SCU) on a flume with 10 m length, 0.8 m width and 0.6 m height. The walls of the flume are made of glass and its floor is made of stainless steel. However, the bottom slope of the flume was zero. In this regard, were considered two weir height with ratio of P/Wu, equal to 1.33 (model 1) and equal to 0.5(model 2). Models were presented in three categories as follows: 1-piano key weir without any parapet wall as a control experiment, 2-unsloped parapet walls (2.5, 3.5 and 4.5 cm height) (a): with discontinues on outlet key crest (b): with discontinues on inlet key and outlet key crest (c) entire of weir crest and 3-sloped parapet walls in three height 2.5, 3.5 and 4.5 cm with length B́ where B́ = (0.25, 0.5, 0.75 and 1.0) ×B. The results show that the un-sloped parapet wall have no significantly effect on the weir efficiency in model 1. however, these walls have efficiency increases up to 15% in model 2. As well as, Un-sloped parapet walls with discontinues on the inlet and outlet key crest improved the weir efficiency in the high head water. So in the parapet wall with 4.5 cm height, discharge coefficient increased up to 70 percent (rather than control test) with discontinues in outlet key part and high head water. Sloped parapet walls on side crest have a little effect on spillway efficiency in model 1, however, in the high head, have efficiency increases up to 19% in model 2. Finally, a statistical relationship was presented for prediction of discharge coefficient in mode sloped and un-sloped parapet wall.

 

In the cases where need to accelerate the consolidation settlement, the length of the drainage path can be reduced by means of vertical drains and flow can be drained radially and vertically. Since the consolidation equation in 3 dimensions is a complex mathematical equation, in this present study the 3-D consolidation equation for isotropic and anisotropic soil was derived in cylindrical coordinates under appropriate boundary conditions, then was solved analytically. Bessel functions were used for analytical solution of consolidation equation. After the analytical solution, the results were analyzed using MATLAB software and the average degree of consolidation versus time was obtained and compared with experimental results of Terzaghi's method. The values of radial drains were considered 0.5, 1, 1.5 and 2 cm. The results showed that, the most difference of 100% settlement velocity between Terzaghi's method and radial-vertical drainage method is related to load of 40 kg of anisotropic soil under unilateral drainage and its value is about 5 days; the least difference of 100% settlement velocity between Terzaghi's method and radial-vertical drainage method is related to load of 2 kg of isotropic soil under bilateral drainage and its value is about 10 minutes. The results of analytical solution was conformed to traditional Terzaghi's solution with negligible consideration vertical drains radius in isotropic soil.

Spillways are important structures for dam safety. Extra flow is passed by this structure in order to do not damage to the dams and related facilities of these structures in times of flood. Cavitation is a destructive phenomenon that can cause damage to these structures. Aeration flow is one way to reducing the damage caused by cavitation. The required air flow is main point in designing aerators. In this study in order to modeling the spillway aerators required air flow experimental methods, multiple linear regression (MLR), neural networks (ANN), fuzzy systems and neuro-fuzzy (ANFIS) methods were used. In order to achieve purposes of this study, 914 data from experimental on Clyde dam spillway hydraulic model and 12 data from experiments by Water Research Center on azad dam hydraulic model were gathered. In order to evaluate the performance of different methods statistical tests including standardized root mean square error (NRMSE), the mean standardized absolute error (NMAE) and correlation coefficient (R) were used. To evaluate the performance of different methods of statistical tests standardized root mean square error (NRMSE), the mean standardized absolute error (NMAE) and correlation coefficient were used. Finding indicated that the ANFIS with lowest NRMSE (0.263) and NMAE (0.143) and most correlation coefficient (0.97) has the best performance.The Fisher's experimental method has the worst performance among methods that used in this study (NRMSE = 26.786). In neural networks and ANFIS methods the pressure difference has the greatest impact on modeling. For the ANFIS and neural networks if this parameter is omitted in the modeling, NRMSE increases to 0.86 and 0.964 respectively. In ANN and ANFIS methods Step height has the Minimum impact on modeling. If Step height parameter omitted in the modeling, NRMSE for ANN increases to 0.668 and for ANFIS increases to 0.305.

The increase of crest effective length of the weirs is one of the important methods for hydraulic efficiency for them. In these conditions, weir can discharges the flood with constant head and the certain head. The labyrinth weirs structures are the samples of them, where have a triangular or trapezoidal shape in plane. Recently, due to many problems, such as highly cost of construction and suitable foundations, the PKW (piano key weir) have been suggested. The hydraulically efficiency of PKW is more than other weirs, duo to the inlet and outlet sloping and the length of crest of these. In the present study are investigated the pier geometric of these weirs where installed under outlet key. In addition, the sloped parapet walls have been evaluated. To achieve these purposes two weirs were built with P/Wu=1.33 (model 1) and 0.5 (model 2) and for each other 3 piers continuous, semi-cylindrical and triangular were considered. However, for each 3 parapet wall with height 2.5, 4.5, 6.5cm and 3 slopes 3, 5.5 and 8 degrees in directly and counter of flow were experimented. The all experiments were performed in the hydraulic and physical model laboratory at the water science faculty. The flume has a 10 m length, 0.8 m width and 0.6 m height, with zero amount slope of bottom. The results showed that triangular pier at both two models have the most efficiency. Hence, the parapet walls at model 1 no any effect on the efficiency and for model 2 with the increase of parapet wall height, it increases. Moreover, in the model 2 the parapet wall at 8° directly slope, capable a increasing of water surface rather than without parapet wall. In this research the equations suggested for estimation of discharge coefficient with sloped parapet walls.