Learning outcomes of the course unit
The course aims to supply the necessary knowledge useful for the design of the most common hydraulic infrastructures that a Civil Engineer meets in the professional experience (aqueducts and urban drainage systems). The aqueduct subject is developed in the main concept only. The urban drainage system topic is developed both at theoretical approach supplementing, where necessary, hydraulic and hydrology background, and supplying the most suitable, by a technical-economical point of view, design solutions. The application of the design theory and practice is carried on during the practices, where the student has to complete the preliminary design of a pipeline for urban aqueduct and an urban sewer system.
Course contents summary
Water distribution networks and sewer systems
General concepts, water requirements, Needs and their temporal variations. Population forecasts, time prospects of design. General schemes. Division in more networks in case of marked difference in height. Pressure in different working conditions.
Pipelines. Revision of uniform motion in full pipes. Flow regimes and flow resistance formulas: Moody’s diagram. Check of gravity pipelines: discharge computation for schemes with two and three reservoirs, even in case of summits and sections with free surface motion; working of a pipeline with given input discharge. Design of gravity pipelines: analysis of the route, design of pipes in two reservoir schemes, economic design for schemes with more than two reservoirs, design in case of marked difference in height or summits; working piezometric lines; break manholes, dissipation valves, venting valves, outlets, try parts, special parts.
Pipes. Materials for pipelines and their characteristics; selection criteria of pipes; junction types, laying and testing of conduits. Accessory devices and valves.
Reservoirs. Main operations of reservoirs.
Distribution networks. Outlines.
Urban drainage systems
General concepts. Aims, network types (unitary or separated); district and local networks. Technical-economical analysis for the selection of the best solution. Population studies and long-term forecasting. Analysis of civil and industrial users. Plano-altimetric outline of the drainage network.
Estimate of waste sewage. Mean daily annual discharge, discharge of the day with maximum use, minimum flow, maximum flow. First flush water, rain discharges to be treated.
Estimate of storm sewage. Design return period. Hydrology revision: probabilistic investigations on intense rainfalls; rainfall intensity-duration curves; design hyetographs, infiltration capacity and surface detection. Hydrologic models of rainfall-runoff transformation; rational method, travel time and storage method; parameter calibration. Outlines of physically based methods; Kinematic wave on plane surface; free surface unsteady flow equations; transitions.
Design of conduits. Revision on uniform and steady flow. Hydraulic computations of conduits: typical cross sections; reliable slopes and velocities; drum traps; links: jumps, curves, confluence, branches, etc. Sewer washing. Manholes, private entries, venting devices.
Spillways. Spillway role. Constructive characteristics. Outflow discharges and pollution transferred to recipients. Regulations. Lateral spillways: theory and design. Leaping and front weirs (outlines).
Siphons. Constructive sketch; design and hydraulic verification. Cleaning.
Storage reservoirs. Aims and field of application. Design of reservoir with kinematic and storage method. Comparison with physically based methods and historical series. Design sketch and constructive types.
Pipes. Materials and their characteristics, choice criteria.
G. IPPOLITO: "Costruzioni Idrauliche",Liguori Ed.,Na 1993.
L. DA DEPPO e C. DATEI: "Fognature", Cortina Ed., PD 1997.
V. MILANO: "Acquedotti", Hoepli Ed., Milano, 1996.
AA.VV. "Sistemi di fognatura", Hoepli Ed., Milano, 1997.
D.CITRINI,G.NOSEDA: "Idraulica", Ambrosiana Ed. Milano, 1990.
G. BECCIU, A. PAOLETTI: Esercitazioni di Costruzioni Idrauliche, CEDAM, Milano, 2003
Lesson Hours 40; Practice Hours 30
Assessment methods and criteria
Written tests (1) on the two subjets of the course and an optional oral exam