José Dolz

Pressures on a stepped spillway

This paper presents an analysis of the pressure field on the steps of a stepped spillway on an RCC dam. The fundamental component of this study is a series of pressure measurements obtained in the fully-developed zone of skimming flow regime along a reduced-size stepped spillway model constructed at the Department of Hydraulic, Maritime and Environmental Engineering Laboratory of the Technical University of Catalonia (UPC). A mathematical model was fitted to the pressure profiles on the horizontal and vertical faces of the steps. This equation allows designers to estimate the possible negative values of pressure on the vertical and horizontal faces of the steps in the fully-developed zone of skimming flow regime

Experimental Study of Subcritical Dividing Flow in an Equal-Width, Four-Branch Junction

An experimental study of the subcritical dividing flow in an equal-width, four-branch junction with two inflows and two outflows is presented. A brief description of the flow characteristics is given. From the analysis of test data, a linear relationship among five nondimensional parameters, including inflow ratio, outflow ratio, Froude number of inflow in one direction, outflow depth ratio, and outflow aspect ratio, is proposed and proven to successfully predict the flow distribution in the junction. It can be used to solve the dividing flow problem in a street junction, and it can be included as a part of a numerical model of a street network involving subcritical flows.

Scour of rock due to the impact of plunging high velocity jets Part I: A state-of-the-art review

ERIK BOLLAERT and ANTON SCHLEISS, Journal of Hydraulic Research, IJHR, Volume 41, 2003, Number 5, pp. 451–464

Surface stormwater hazard assessment in steep urban areas. Case of the city of Mendoza, Argentina

The current paper focusses on the hazard assessment associated with urban runoff on streets. A review of the existing criteria to evaluate such a hazard is made. Two new criteria based on theoretical analysis of the waters force acting on a static pedestrian are presented: no slipping criterion and stability to tilt criterion. According to these criteria, either a maximum depth, or a maximum velocity or some relation between depths and velocities should be fulfilled in order to guarantee the pedestrians and drivers safety in the case of medium to large storms. A one-dimensional numerical model is used to solve the urban storm runoff within a street network. This model is applied to an urban watershed of the city of Mendoza (Argentina), obtaining the runoff values belonging to return periods of 5, 10 and 25 years. The results are evaluated bearing in mind four hazard criteria. In conclusion, the numerical model is shown to be a useful tool in relation to the application of the hazards criteria. It is also conclude that an effort should be made to determine specific hazard criteria based on experimental data.

Experimental and numerical modelling of symmetrical four-branch supercritical cross junction flow

The discussers congratulate the authors for their work and would like to raise some questions and comments about their results and statements. The paper compares (i) the computed with the measured flow depths for five flow configurations and (ii) the computed with the measured discharges for more than 200 configurations. The authors found discrepancies concerning the prediction of the location and the thickness of the oblique jumps mainly because these are set on one cell in the numerical model. The discussers argue that the prediction of the discharge distribution at the junction through a “quality indicator” as suggested by the authors, namely EQT in Section 4.2, p. 728, is somewhat misleading. The authors compared the difference between the computed and measured outflows in the x direction with the total inflow discharge, whereas they should have used the measured outflow in the x direction as EQT