18
1735-0522
352
Optimum Design of Water Conveyance Systems by Ant Colony Optimization Algorithms
Afshar
A.
Abbasi
H.
Jalali
M. R.
1
3
2006
4
1
1
13
03
11
2009
11
01
2014
Water conveyance systems (WCSs) are costly infrastructures in terms of materials,
construction, maintenance and energy requirements. Much attention has been given to the
application of optimization methods to minimize the costs associated with such infrastructures.
Historically, traditional optimization techniques have been used, such as linear and non-linear
programming. In this paper, application of ant colony optimization (ACO) algorithm in the design
of a water supply pipeline system is presented. Ant colony optimization algorithms, which are based
on foraging behavior of ants, is successfully applied to optimize this problem. A computer model is
developed that can receive pumping stations at any possible or predefined locations and optimize
their specifications. As any direct search method, the mothel is highly sensitive to setup parameters,
hence fine tuning of the parameters is recommended.
353
Numerical simulation of Air-Water flow in bottom outlet
Shamsai
A.
Soleymanzadeh
R.
1
3
2006
4
1
14
33
03
11
2009
Flow regime in dam's bottom outlet is divided in pressurized flow and free surface flow by
the gate located for discharge control. Down stream tunnel involves high velocity Multi component
Air –water flow studied by mathematical model. In this research work, we used Finite volume
mixture two phase flow model. Because of high Reynolds number, standard two equations k-e
turbulence model was used. Model was verified by backward-facing step flow and results have been
compared with experiments founded by Durst and Schmitt. Air demand ratio has been determined
as function of Froude number at contracted section. Flow patterns have been compared at two
categories of slug & stratified flows, Air mean concentration profile has been obtained at down
stream tunnel. Comparison of flow pattern at two case with and without of aeration was
investigated. Pressure drop behind of the gate and formation of vortex flow after the gate section
have been discussed. Measurement of flow discharge and determination of contraction coefficient
of the gate was outlined.
354
A Corrected Time-Area Technique for One-dimensional Flow
Saghafian
B.
Shokoohi
A.R.
1
3
2006
4
1
34
41
03
11
2009
11
01
2014
Time–Area method is one of the most widely applied techniques of watershed routing, and
can be potentially used as a distributed model. In this paper, a fundamental flaw in the arrangement
of subareas in the original time-area histogram is identified for one-dimensional flow. This is
conducted on the basis of comparing time-area hydrograph with that of the kinematic wave theorem.
Accordingly, a revised time-area algorithm is developed as a substitute for the original time-area.
It is proved that in the revised approach, subareas must be reversely arranged. It is also shown that
the revised time-area hydrograph is in perfect agreement with the hydrograph derived by the
kinematics wave theory.
355
Impact Assessment of Climate Change on Rainfall over a Small Catchment
Zahabiyoun
B.
1
3
2006
4
1
42
53
03
11
2009
11
01
2014
A methodology is presented for the stochastic generation of daily rainfall which accounts
for changes to the climatic inputs. The focus of the study is an example catchment in Iran. The
methodology addresses the inability of GCMs to provide suitable future scenarios for the time and
space scales required for a water resource impact assessment for a small catchment. One stochastic
model for rainfall (Neyman-Scott Rectangular Pulses, NSRP, model) is used to generate daily
rainfall sequences and then validated using historic records. For present climate conditions, the
NSRP model is fitted to observed rainfall statistics. GCM outputs are then downscaled using
regressions between atmospheric circulation indices (ACIs) and rainfall statistics. The
relationships are then used to predict the rainfall statistics for future conditions using GCM outputs.
In this respect, climate change impacts are studied and assessed in this paper. Generated rainfall
scenario can then be used as inputs to a rainfall-runoff model in order to generate daily streamflow
data which is not investigated here.
356
MEDIUM DENSE NON-CEMENTED CARBONATE SAND UNDER REVERSED CYCLIC LOADING
Salehzadeh
H.
Procter
D.C.
Merrifield
C.M.
1
3
2006
4
1
54
63
03
11
2009
11
01
2014
Carbonate materials are mostly found in tropical areas, where exploiting gas and oil
resources are of high concern. Their unique behavior under shear loading first was recognised
during oil resources investigations in the Persian Gulf. Off-shore structures have been placed on
carbonate soils which are highly crushable.During storms cyclic loading imposes on the bases of
structures lied down on seabed. Cyclic loading, therefore, may trigger liquefaction phenomenon
which leads to soil collapse and a catostrophic event. Therefore, stability of these expensive
structures need to be investigated. To this aim carbonate sand in medium dense to medium dense
state was considered and its response under varied cyclic shear stress ratio was studied.
357
An Investigation to Determine the Minimum Acceptable Roadway Condition for Iran’s Highways
Behbahani
H.
Elahi
S.M.
1
3
2006
4
1
64
76
03
11
2009
To properly plan for construction, repair, maintenance, and reconstruction of highways the
minimum acceptable roadway condition is needed information. This, along with other pavement
management tools, will help select the most desirable roadway alternatives. In this research the
minimum acceptable conditions are developed based on an opinion survey of non-technical but
high-level decision makers. Roadway roughness, expressed as international roughness index (IRI),
is used as the measurement criteria. Because IRI is a widely known, acceptable, and a uniformly
measurable index, it is used for the purpose of this research. The minimum IRI values developed
here will help managers, planners, and engineers in prioritizing their plans and projects. Iran has
a central planning system, hence having a minimum acceptable IRI will help in producing
homogeneity in decision making. A questionnaire is sent to top level and influential managementlevel
officials who have a decisive input in highway matters. The officials are asked to choose the
minimum acceptable service level of different types of roadways and classifications. Naturally,
roadways with higher levels of importance would require higher service levels. The answers to the
survey questionnaires are investigated to determine a preferred minimum acceptable roadway
condition. The IRI is computed using a mechanical device enabling a more uniform data collection.
The IRI was first proposed by The World Bank as a standard roughness statistic. Extensive research
has proven that the IRI can be related to pavement condition. The result of the opinion survey is
investigated to determine the minimum levels acceptable for each category. The responses show
distinct preference patterns for most of the roadway types. Survey results are investigated by plotting
and analyzing them. Based on road user’s perception of roadway condition using guidelines from
AASHTO, the Corp of Engineers, and related research work. The appropriate IRI limits and ranges
are determined for Iran’s highways. These values are adjusted to obtain final values for Iran. The
result, shown in a table, gives upper and lower IRI values accepted and recommended for Iran’s
highways. The result of this research work is specifically useful in developing specifications for new
pavement design, accepting new pavement from contractors, pavement management, highway
planning, and in roadway life cycle cost analysis decision making. The results are subject to
refinement over time.