Abstract: The effect of artificial pozzolan (waste brick) on the
physico-chemical properties of cement manufactured was
investigated. The waste brick is generated by the manufacture of
bricks. It was used in the proportions of 0%, 5%, 10%, 15% and 20%
by mass of cement to study its effect on the physico-chemical
properties of cement incorporating artificial pozzolan. The physicochemical
properties of cement at anhydrous state and the hydrated
state (chemical composition, specific weight, fineness, consistency of
the cement paste and setting times) were studied. The experimental
results obtained show that the quantity of pozzolanic admixture
(waste brick) of cement manufactured is the principal parameter who
influences on the variation of the physico-chemical properties of the
cement tested.
Abstract: A new analytical method to predict the torsional
capacity and behavior of R.C multi-cell box girders strengthened with
carbon fiber reinforced polymer (CFRP) sheets is presented.
Modification was done on the Softened Truss Model (STM) in the
proposed method; the concrete torsional problem is solved by
combining the equilibrium conditions, compatibility conditions and
constitutive laws of materials by taking into account the confinement
of concrete with CFRP sheets. A specific algorithm is developed to
predict the torsional behavior of reinforced concrete multi-cell box
girders with or without strengthening by CFRP sheets. Applications
of the developed method as an assessment tool to strengthened multicell
box girders with CFRP and first analytical example that
demonstrate the contribution of the CFRP materials on the torsional
response is also included.
Abstract: The nearly 21-year-old Jiujiang Bridge, which is suffering from uneven line shape, constant great downwarping of the main beam and cracking of the box girder, needs reinforcement and cable adjustment. It has undergone cable adjustment for twice with incomplete data. Therefore, the initial internal force state of the Jiujiang Bridge is identified as the key for the cable adjustment project. Based on parameter identification by means of static force test data, this paper suggests determining the initial internal force state of the cable-stayed bridge according to the cable force-displacement relationship parameter identification method. That is, upon measuring the displacement and the change in cable forces for twice, one can identify the parameters concerned by means of optimization. This method is applied to the cable adjustment, replacement and reinforcement project for the Jiujiang Bridge as a guidance for the cable adjustment and reinforcement project of the bridge.
Abstract: Rise/span ratio has been mentioned as one of the
reasons which contribute to the lower buckling load as compared to
the Classical theory buckling load but this ratio has not been quantified
in the equation. The purpose of this study was to determine a more
realistic buckling load by quantifying the effect of the rise/span ratio
because experiments have shown that the Classical theory
overestimates the load. The buckling load equation was derived based
on the theorem of work done and strain energy. Thereafter, finite
element modeling and simulation using ABAQUS was done to
determine the variables that determine the constant in the derived
equation. The rise/span was found to be the determining factor of the
constant in the buckling load equation. The derived buckling load
correlates closely to the load obtained from experiments.
Abstract: This evaluation of land supply system performance in
China shall examine the combination of government functions and
national goals in order to perform a cost-benefit analysis of system
results. From the author's point of view, it is most productive to
evaluate land supply system performance at moments of system
transformation for the following reasons. The behavior and
input-output change of beneficial results at different times can be
observed when the system or policy changes and system performance
can be evaluated through a cost-benefit analysis during the process of
system transformation. Moreover, this evaluation method can avoid
the influence of land resource endowment. Different land resource
endowment methods and different economy development periods
result in different systems. This essay studies the contents, principles
and methods of land supply system performance evaluation. Taking
Beijing as an example, this essay optimizes and classifies the land
supply index, makes a quantitative evaluation of land supply system
performance through principal component analysis (PCA), and finally
analyzes the factors that influence land supply system performance at
times of system transformation.
Abstract: A method to predict the column size for displacement based design of reinforced concrete frame buildings with higher target inter storey drift is reported here. The column depth derived from empirical relation as a function of given beam section, target inter-story drift, building plan features and common displacement based design parameters is used. Regarding the high drift requirement, a minimum column-beam moment capacity ratio is maintained during capacity design. The method is used in designing four, eight and twelve story frame buildings with displacement based design for three percent target inter storey drift. Non linear time history analysis of the designed buildings are performed under five artificial ground motions to show that the columns are found elastic enough to avoid column sway mechanism assuring that for the design the column size can be used with or without minor changes.
Abstract: A direct search approach to determine optimal reservoir operating is proposed with ant colony optimization for continuous domains (ACOR). The model is applied to a system of single reservoir to determine the optimum releases during 42 years of monthly steps. A disadvantage of ant colony based methods and the ACOR in particular, refers to great amount of computer run time consumption. In this study a highly effective procedure for decreasing run time has been developed. The results are compared to those of a GA based model.
Abstract: –In this paper the damage in clamped-free, clampedclamped and free-free beam are analyzed considering samples
without and with structural modifications. The damage location is
investigated by the use of the bispectrum and wavelet analysis. The
mathematical models are obtained using 2D elasticity theory and the
Finite Element Method (FEM). The numerical and experimental data
are approximated using the Particle Swarm Optimizer (PSO) method
and this way is possible to adjust the localization and the severity of
the damage. The experimental data are obtained through
accelerometers placed along the sample. The system is excited using
impact hammer.
Abstract: Flood management is one of the important fields in
urban storm water management. Floods are influenced by the
increase of huge storm event, or improper planning of the area. This study mainly provides the flood protection in four stages; planning,
flood event, responses and evaluation. However it is most effective then flood protection is considered in planning/design and
evaluation stages since both stages represent the land development of the area. Structural adjustments are often more reliable than nonstructural
adjustments in providing flood protection, however
structural adjustments are constrained by numerous factors such as
political constraints and cost. Therefore it is important to balance
both adjustments with the situation. The technical decisions provided
will have to be approved by the higher-ups who have the power to
decide on the final solution. Costs however, are the biggest factor in
determining the final decision. Therefore this study recommends
flood protection system should have been integrated and enforces
more in the early stages (planning and design) as part of the storm
water management plan. Factors influencing the technical decisions
provided should be reduced as low as possible to avoid a reduction in
the expected performance of the proposed adjustments.
Abstract: Flat double-layer grid is from category of space structures that are formed from two flat layers connected together with diagonal members. Increased stiffness and better seismic resistance in relation to other space structures are advantages of flat double layer space structures. The objective of this study is assessment and calculation of Behavior factor of flat double layer space structures. With regarding that these structures are used widely but Behavior factor used to design these structures against seismic force is not determined and exact, the necessity of study is obvious. This study is theoretical. In this study we used structures with span length of 16m and 20 m. All connections are pivotal. ANSYS software is used to non-linear analysis of structures.
Abstract: The seismic rehabilitation designs of two reinforced
concrete school buildings, representative of a wide stock of similar
edifices designed under earlier editions of the Italian Technical
Standards, are presented in this paper. The mutual retrofit solution
elaborated for the two buildings consists in the incorporation of a
dissipative bracing system including pressurized fluid viscous springdampers
as passive protective devices. The mechanical parameters,
layouts and locations selected for the constituting elements of the
system; the architectural renovation projects developed to properly
incorporate the structural interventions and improve the appearance
of the buildings; highlights of the installation works already
completed in one of the two structures; and a synthesis of the
performance assessment analyses carried out in original and
rehabilitated conditions, are illustrated. The results of the analyses
show a remarkable enhancement of the seismic response capacities of
both structures. This allows reaching the high performance objectives
postulated in the retrofit designs with much lower costs and
architectural intrusion as compared to traditional rehabilitation
interventions designed for the same objectives.
Abstract: The provision of urban public transport in Indonesia is not free of problems. Some of the problems include: an overall lack of capacity, lack of quality and choice, severe traffic congestions and insufficient fund to renew and repair vehicles. Generally, the comfort and quality of the city bus is poor, and many of the vehicles are dilapidated and dirty. Surveys were carried out in the city of Yogyakarta, by counting city bus vehicles and occupancies, interviewing the bus passengers, drivers and institutional staffs, who involve in public transport management. This paper will then analyze the possible plan to develop the public transport system to become more attractive and to improve the public transport management. The short, medium and long term plans are analyzed, to find the best solutions. Some constraints such as social impacts and financial impact are also taken into accounts.
Abstract: A laboratory study on the influence of compactive
effort on expansive black cotton specimens treated with up to 8%
ordinary Portland cement (OPC) admixed with up to 8% bagasse ash
(BA) by dry weight of soil and compacted using the energies of the
standard Proctor (SP), West African Standard (WAS) or
“intermediate” and modified Proctor (MP) were undertaken. The
expansive black cotton soil was classified as A-7-6 (16) or CL using
the American Association of Highway and Transportation Officials
(AASHTO) and Unified Soil Classification System (USCS),
respectively. The 7day unconfined compressive strength (UCS)
values of the natural soil for SP, WAS and MP compactive efforts are
286, 401 and 515kN/m2 respectively, while peak values of 1019,
1328 and 1420kN/m2 recorded at 8% OPC/ 6% BA, 8% OPC/ 2% BA
and 6% OPC/ 4% BA treatments, respectively were less than the
UCS value of 1710kN/m2 conventionally used as criterion for
adequate cement stabilization. The soaked California bearing ratio
(CBR) values of the OPC/BA stabilized soil increased with higher
energy level from 2, 4 and 10% for the natural soil to Peak values of
55, 18 and 8% were recorded at 8% OPC/4% BA 8% OPC/2% BA
and 8% OPC/4% BA, treatments when SP, WAS and MP compactive
effort were used, respectively. The durability of specimens was
determined by immersion in water. Soils treatment at 8% OPC/ 4%
BA blend gave a value of 50% resistance to loss in strength value
which is acceptable because of the harsh test condition of 7 days
soaking period specimens were subjected instead of the 4 days
soaking period that specified a minimum resistance to loss in strength
of 80%. Finally An optimal blend of is 8% OPC/ 4% BA is
recommended for treatment of expansive black cotton soil for use as
a sub-base material.
Abstract: Roadways in Amman city face many problems consequent upon poor drainage systems. Evaluation tools are necessary to identify those roads needing improvement in their drainage system, and those needing regular maintenance. This work aims at evaluating drainage conditions in selected roadways in Amman city with the intent of identifying the problems encountered in their drainage systems. Three sites in the vicinity of Amman city have been selected and then inspected via several field visits to determine the state of their existing drainage systems and define the major problems encountered in these systems. The evaluation tool used in this study is based on visual inspection supported by photographs that depicted the defined problems. Following the field assessment, the drainage system in each road was rated as excellent, fair, good, or poor. The study reveals that more than 60% of the roadways in the selected sites were in poor drainage conditions, which lead to tremendous environmental problems. This assessment serves as a guide for local decision makers to help plan for the maintenance of Amman city roadways drainage systems, and propose ways of managing the associated problems.
Abstract: In this study, shaking table tests are performed to investigate the behavior of excess pore water pressure in different soft soil-foundations of soil-structure interaction (SSI) system. The variation of the behaviors under cycled minor shock is observed. Moreover, The generation and variation mechanism of excess pore water pressure under earthquake excitation in different soft soilfoundations are analyzed and discussed.
Abstract: In this paper, the optimum weight and cost of a laminated composite plate is seeked, while it undergoes the heaviest load prior to a complete failure. Various failure criteria are defined for such structures in the literature. In this work, the Tsai-Hill theory is used as the failure criterion. The theory of analysis was based on the Classical Lamination Theory (CLT). A newly type of Genetic Algorithm (GA) as an optimization technique with a direct use of real variables was employed. Yet, since the optimization via GAs is a long process, and the major time is consumed through the analysis, Radial Basis Function Neural Networks (RBFNN) was employed in predicting the output from the analysis. Thus, the process of optimization will be carried out through a hybrid neuro-GA environment, and the procedure will be carried out until a predicted optimum solution is achieved.
Abstract: Land surface temperature (LST) is an important
parameter to study in urban climate. The understanding of the
influence of biophysical factors could improve the establishment of
modeling urban thermal landscape. It is well established that climate
hold a great influence on the urban landscape. However, it has been
recognize that climate has a low priority in urban planning process,
due to the complex nature of its influence. This study will focus on
the relatively cloud free Landsat Thematic Mapper image of the study
area, acquired on the 2nd March 2006. Correlation analyses were
conducted to identify the relationship of LST to the biophysical
factors; vegetation indices, impervious surface, and albedo to
investigate the variation of LST. We suggest that the results can be
considered by the stackholders during decision-making process to
create a cooler and comfortable environment in the urban landscape
for city dwellers.
Abstract: The aim of this study was to develop a storm water quality improvement strategy plan (WQISP) which assists managers and decision makers of local city councils in enhancing their activities to improve regional water quality. City of Gosnells in Western Australia has been considered as a case study. The procedure on developing the WQISP consists of reviewing existing water quality data, identifying water quality issues in the study areas and developing a decision making tool for the officers, managers and decision makers. It was found that land use type is the main factor affecting the water quality. Therefore, activities, sources and pollutants related to different land use types including residential, industrial, agricultural and commercial are given high importance during the study. Semi-structured interviews were carried out with coordinators of different management sections of the regional councils in order to understand the associated management framework and issues. The issues identified from these interviews were used in preparing the decision making tool. Variables associated with the defined “value versus threat" decision making tool are obtained from the intensive literature review. The main recommendations provided for improvement of water quality in local city councils, include non-structural, structural and management controls and potential impacts of climate change.
Abstract: The use of solar control film on windows as one of
solar passive strategies for building have becoming important and is
gaining recognition. Malaysia located close to equator is having
warm humid climate with long sunshine hours and abundant solar
radiation throughout the year. Hence, befitting solar control on
windows is absolutely necessary to capture the daylight whilst
moderating thermal impact and eliminating glare problems. This is
one of the energy efficient strategies to achieve thermal and visual
comfort in buildings. Therefore, this study was carried out to
investigate the effect of window solar controls on thermal and visual
performance of naturally ventilated buildings. This was conducted via
field data monitoring using a test building facility. Four types of
window glazing systems were used with three types of solar control
films. Data were analysed for thermal and visual impact with
reference to thermal and optical characteristics of the films. Results
show that for each glazing system, the surface temperature of
windows are influenced by the Solar Energy Absorption property, the
indoor air temperature are influenced by the Solar Energy
Transmittance and Solar Energy Reflectance, and the daylighting by
Visible Light Transmission and Shading Coefficient. Further
investigations are underway to determine the mathematical relation
between thermal energy and visual performance with the thermal and
optical characteristics of solar control films.
Abstract: Investigation of sandy clay behavior is important since
urban development demands mean that sandy clay areas are
increasingly encountered, especially for transportation
infrastructures. This paper presents the results of the finite element
analysis of the direct shear test (under three vertical loading 44, 96
and 192 kPa) and discusses the effects of different parameters such as
cohesion, friction angle and Young's modulus on the shear strength of
sandy clay. The numerical model was calibrated against the
experimental results of large-scale direct shear tests. The results have
shown that the shear strength was increased with increase in friction
angle and cohesion. However, the shear strength was not influenced
by raising the friction angle at normal stress of 44 kPa. Also, the
effect of different young's modulus factors on stress-strain curve was
investigated.