Universitā degli studi di Roma “Tor Vergata” - ART - TORVERGATA ...

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clay soil-backfill than in chalk and sand one (O’Reill et al., 1989). Root intrusion The roots can break the sewer walls as well as open the joints. Other factors Sewage characteristics Inappropriate maintenance method Age of sewer Sediment friction Wastewater can be corrosive, in particular if it is characterized by: pH200 mg/L and CO2>0.23 mg/L*carbonate hardness for concrete and asbestos cement (WSA/FWR,1993). Davies at al. (2001B) estimated that separated sewer can more likely be damaged than combined one. The cleaning by means of pump jetting can erode the inner sewer wall It is not the age itself, principally, but the period of construction according to the historical and technological development. An interesting analysis is given by WRc (2001) which is based on a comparison among the effects of sewer defect size, hydraulic surcharge, groundwater level with water depth and soil type on ground loss. The worst situation is for a submerged sewer with severe defects, laid in a sandy fine sand or fine sand subjected to frequent high magnitude hydraulic surcharges; whereas one of the best picture is a non-submerged sewer with small defects, laid in a medium to high plasticity clays never subjected to hydraulic surcharges. The location of the experimental areas in Rome has been done on the basis of this analysis, and the investigated sewer systems (called Torraccia and Infenetto) were chosen because one was supposed to represent the best situation (Torraccia) and the worst situation (Infernetto). Finally, Fenner (2000) identified some informations to be collected for completely characterizing an urban sewer systems, those information can support the decision for a strategic rehabilitation planning. They are divided in three groups: physical attributes, data by field visits and other. In particular: 1. the key physical attributes are: levels cover manhole, pipe sizes, invert levels of incoming and outgoing pipes and pipe material; 19
2. data by field visits: condition of manholes, overall integrity of the manhole structure, degree of tree roots, silt and evidence of surcharge levels; 3. other: pipe shape, function/location/condition of the upstream catchment, hydraulic load and frequency surcharge, drift/underlying geology, groundwater level, traffic and surface loadings, age and construction techniques, event history and frequency of CSO operation, years since last inspection as well as previous maintenance and rehabilitation history. Even though all these informations are useful when multi-parametric models are used for assessing and forecasting the urban sewer state, gathering them is a very cost effective work, then the infomations’ colletion should be only concentrated on those parts of the sewer asset that are at most risk from a likely future failure. A brief description of some models developed so far for sewer deterioration assessment in order to plan a prioritizing interventions is given in the following paragraph. 1.3.2 Sewer deterioration modelling The functionality of the sewer system includes hydraulic, environmental and structural aspects, and for a good performance of the system the operators should provide an efficient rehabilitation planning. The urgency of sewer rehabilitation reflects the criterion used for classifying the damaged reaches in a priority way for the renovation, tools for the optimization of sewer rehabilitation can be summarized in three points (Baur, 2003): 1. development of a rehabilitation strategy; 2. selection of cost-efficient rehabilitation projects; 3. choice of the most appropriate rehabilitation technology for the selected projects. While for understanding how the researchers approached at pipe deterioration modelling, it is profitable to know how they have studied the water pipe deterioration. Although recently more efforts have been done on improving the quality of this infrastructure, there are several old sewer systems whose there are not historical data about the their deterioration, but only the collapse of sewer pipes have been recorded over the years. Nevertheless, some historical failure records for water pipes have been available, and on these cases researchers can develop models for forecasting pipe deterioration. 20
Page 1 and 2: Università degli studi di Roma “
Page 3 and 4: INDEX CHAPTER 1 THE PROBLEM........
Page 5 and 6: ANNEX 6 - PRIGIOBBE, V.; GIULIANELL
Page 7 and 8: FIGURE INDEX FIG. 1.3.1: PPIS FOR I
Page 9 and 10: MOTIVATION This dissertation presen
Page 11 and 12: INTRODUCTION The thesis is divided
Page 13 and 14: 2000; Jorgesen and halling-Sorensen
Page 15 and 16: Concerning virus transport and surv
Page 17 and 18: The motivation of the study of the
Page 19: Sewer material Sewer joint type and
Page 23 and 24: to be large enough to provide signi
Page 25 and 26: Fig. 1.3.2: PPIs for infiltration (
Page 27 and 28: well as cost-effective. Although it
Page 29 and 30: drain and sewer system outside buil
Page 31 and 32: Tab. 1.4-1: how to use diagnostic t
Page 33 and 34: Dietrich, D. R..; Webb, S.F.; Petry
Page 35 and 36: Rauch, W.; Stegner, Th. (1994). The
Page 37 and 38: for the calibration and/or validati
Page 39 and 40: If the complete mixing occurs the e
Page 41 and 42: 2.2.3 Hydrodynamic background of QU
Page 43 and 44: The three dimensional equation (Eq.
Page 45 and 46: et = νt Eq. 2.2-15 but for buoyant
Page 47 and 48: where y is the vertical axis [m] an
Page 49 and 50: Fig. 2.2.4: Concentration profile d
Page 51 and 52: Mid-Field and Transverse Mixing The
Page 53 and 54: where = = u * and Lt = water
Page 55 and 56: The mixing distances are determined
Page 57 and 58: The methods used for measuring the
Page 59 and 60: This equation gives a Gaussian spat
Page 61 and 62: where Kx is undimensionalized by b
Page 63 and 64: time-varying concentration input at
Page 65 and 66: at the confluence, because if exfil
Page 67 and 68: e. at the natural site the discorda
Page 69 and 70: 2.2.4 Application Advection-Dispers
Page 71 and 72:
2.2.5 Sampling and Measurements In
Page 73 and 74:
2.3 Methods for Quantifying the Inf
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an urban sewer network. The chemica
Page 77 and 78:
the various isotopes of an element
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3. biological reaction due to organ
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Fig. 2.3.4 Fractionation factors α
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isotopic fractionation than faster
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The dashed lines in Fig. 2.3.5 show
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In Italy, Longinelli and Selmo (200
Page 89 and 90:
egions and it has been applied for
Page 91 and 92:
2.4 Reference Best, J. L., and Roy,
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Kracht, O.; Gresch, M.; de Bennedit
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CHAPTER 3 Experimental Design and F
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and B 2 ⎛ ⎜ = ⎜2 ⎜ ⎜ ⎝
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After a general uncertainty analysi
Page 101 and 102:
3.3 QUEST In this paragraph, the QU
Page 103 and 104:
t= endIpeak M 2 e'( C exf = 1− t=
Page 105 and 106:
Tab. 3.3-1: sources of uncertainty
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discussed, and a mathematical appro
Page 109 and 110:
Overlapping Peak routine) is the ro
Page 111 and 112:
Fig. 3.3.7: Conductivity peaks in g
Page 113 and 114:
# INTEGRATION of Reference and Indi
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# regression time definition # ====
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samp[,2:length(par.vector.mean)]
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e
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n.ref
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{ Q.Ref[i]
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} # Plot # ==== range
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3.4 QUEST-C For the application of
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3.6 POLLUTOGRAPH METHOD The equatio
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Fig. 3.6.3: COD measurements after
Page 133 and 134:
Tab. 3.6-1 and the hydrograph separ
Page 135:
Annex 1 Giulianelli, M.; Prigiobbe,
Page 147 and 148:
10 th International Conference on U
Page 149:
Annex 3 Giulianelli, M.; Mazza, M.;
Page 175:
Annex 5 Rieckermann, J.; Bareš, V.
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Application of a novel method for a
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Fig. 1 right: fractionation of 18 O
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The experimental area called Infern
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Table 1 data of isotopic compositio
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During the storage of wastewater sa
Page 197 and 198:
Fig. 7 error propagation with Monte
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Majoube, M., 1971. Fractionnement e
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th 16P P European Junior Scientist
Page 203 and 204:
By the administrative level, the ma
Page 205 and 206:
Fig. 2 - “Node” topology elemen
Page 207 and 208:
By topologic overlay (overlapping t
Page 209:
References: [1] United Nations Divi
Page 213 and 214:
VALENTINA PRIGIOBBE (A) , CLAUDIO S
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associare contemporaneamente alle m
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Fig. 2 - Sonda utilizzata per le mi
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Conductivity [microS/cm] 3700 3400
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Allo stato attuale di avanzamento d
Page 223 and 224:
I metodi presentati in questo artic
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precipitazioni è variabile tra -9
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Area di indagine L’area speriment
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δ 18 O [per mille] 2.00 1.00 0.00
Page 231 and 232:
Tabella 1 a cui si deve aggiungere
Page 233:
10 th International Conference on U
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