Abstract
Landslides are one of the natural disasters that cause a lot of financial and human losses every year It will be all over
the world. China, especially. The Mainland China can be divided into 12 zones, including 4 high susceptibility zones, 7 medium
susceptibility zones and 1 low susceptibility zone, according to landslide proneness. Climate and physiography are always at risk
of landslides. The purpose of this research is to prepare a landslide hazard map using the Hierarchical Analysis Process method.
In the GIS environment, it is in a part of China watershed. In order to prepare a landslide hazard map, first with Field studies, a
distribution map of landslides in the area and then a map of factors affecting landslides were prepared. In the next stage, the
factors are prioritized using expert opinion and hierarchical analysis process and nine factors including height, slope, slope
direction, geological units, land use, distance from Waterway, distance from the road, distance from the fault and rainfall map
were selected as effective factors. Then Landslide risk zoning in the region was done using the hierarchical analysis process
model. The results showed that the three factors of geological units, distance from the road and slope are the most important
have had an effect on the occurrence of landslides in the region, while the two factors of fault and rainfall have the least effect
The landslide occurred in the region.
Key Words
analysis process method; geological hazards; GIS environment; landslides
Address
Peixi Guo:Xijing University, Xi'an, Shaanxi,710123, China
Seyyed Behnam Beheshti:Department of Civil Engineering, Khomein Branch, Islamic Azad University, Khomein, Iran
Maryam Shokravi:Department of Education, Mehrab High School, Saveh, Iran
Amir Behshad:Faculty of Technology and Mining, Yasouj University, Choram 75761-59836, Iran
Abstract
To investigate the load bearing capacity of axially preloaded circular hollow section (CHS) stub columns
strengthened by carbon fiber reinforced polymer (CFRP), theoretical analysis is carried out. The yield strength and the ultimate
strength of a CFRP strengthened preloaded CHS stub column are determined at the yielding of the CHS tube and at the CFRP
fracture, respectively. Theoretical models are proposed and corresponding equations for calculating the static strengths, including
the yield strength and the ultimate strength, are presented. Through comparison with reported experimental results, the
theoretical predictions on the static strengths are proved to be accurate. Through finite element (FE) analyses, parametric studies
for 258 models of CFRP strengthened preloaded CHS stub columns are conducted by considering different values of tube
diameter, tube thickness, CFRP layer and preloading level. The static strengths of the 258 models predicted from presented
equations are proved to be in good agreement with FE simulations when the diameter-to-thickness ratio is less than 90ε
2
. The
parametric study indicates that the diameter and the thickness of the steel tube have great effects on CFRP strengthening
efficiency, and the recommended ranges of the diameter and the thickness are proposed.
Abstract
Seismic retrofit of an existing steel-reinforced concrete hospital building that features innovative use of a continuous
energy-dissipative steel column (CEDC) system is presented in this paper. The special system has been adopted to provide an
efficient solution taking into account the difficulties of applying traditional intervention techniques to minimize the impact on
architectural functionality and avoid the loss of building function and evacuation during the retrofit implementation. The lateral
stiffness and strength of the CEDC system were defined based on the geometric and mechanical properties of the steel strip
dampers. The hysteretic behavior under cyclic loadings was defined using a simplified numerical model. Its effectiveness was
validated by comparing the results of full-scale experimental data available from the literature. All the main design
considerations of the retrofitting plan are described in detail. The effectiveness of the proposed retrofitting system was
demonstrated by nonlinear time-history analyses under different sets of earthquake-strong ground motions. The analysis results
show that the CEDC system is effective in controlling the deformation pattern and significantly reducing damage to the existing
structure during major earthquakes.
Address
Massimiliano Ferraioli and Biagio Laurenza:Department of Engineering, University of Campania "Luigi Vanvitelli", Via Roma 9, 81031, Aversa, Italy
Angelo Lavino and Gianfranco De Matteis:Department of Architecture and Industrial Design, University of Campania "Luigi Vanvitelli", Via San Lorenzo 31, 81031, Aversa, Italy
Ciro Frattolillo:National Cancer Institute "G. Pascale Foundation", Naples, Italy
Abstract
The strong column-weak beam (SCWB) moment ratio is specified in AISC 341 to prevent an abrupt column sway
in steel special moment frames (SMFs) during earthquakes. Even when the SCWB requirement is satisfied for an SMF, a
column-sway can develop in the SMF. This is because the contribution of the composite beam action developed in the concrete
floor slab and its supporting beams was not included while calculating the SCWB moment ratio. In this study, we developed a
new method for calculating the SCWB moment ratio that included the contribution of composite beam action. We evaluated the
seismic collapse performance of the SMFs considering various risk categories and building heights. We demonstrated that the
collapse performance of the SMFs was significantly improved by using the proposed SCWB equation that also satisfied the
target performance specified in ASCE 7.
Key Words
column sway mechanism; composite beam action; moment ratio; seismic collapse performance; special
moment frames; strong column-weak beam
Address
Sang Whan Han and Taeo Kim: Department of Architectural Engineering, Hanyang University, 04763 Seoul, Korea
Soo Ik Cho:Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, IL 61801, United States
Kihak Lee:Department of Architectural Engineering, Sejong University, 05006 Seoul, Korea
Abstract
Stability of laminated plate under thermal load varied linearly along thickness, is developed using a higher order
displacement field which depend on a parameter "m", whose value is optimized to get results closest to three-dimension
elasticity results. Hamilton, s principle is used to derive equations of motion for laminated plates. These equations are solved
using Navier-type for simply supported boundary conditions to obtain non uniform critical thermal buckling and fundamental
frequency under a ratio of this load. Many design parameters of cross ply and angle ply laminates such as, number of layers,
aspect ratios and E1/E2 ratios for thick and thin plates are investigated. It is observed that linear and uniform distribution of
temperature reduces plate frequency.
Key Words
angle ply plate; critical temperature; cross ply plate; linear thermal load; shear deformation theory
Address
Widad Ibraheem Majeed and Ibtehal Abbas Sadiq:Department of Mechanical Engineering, College of Engineering, University of Baghdad, Baghdad, Republic of Iraq
Abstract
The goal of this work is to create a new and improved GWO (Grey Wolf Optimizer), the so-called Robot GWO
(RGWO), for dynamic and static target tracking involving multiple robots in unknown environmental conditions. From applying
ourselves with the Gray Wolf Optimization Algorithm (GWO) and how it works, as the name suggests, it is a nature-inspired
metaheuristic based on the behavior of wolf packs. Like other nature-inspired metaheuristics such as genetic algorithms and
firefly algorithms, we explore the search space to find the optimal solution. The results also show that the improved optimal
control method can provide superior power characteristics even when operating conditions and design parameters are changed.
Key Words
feedback and feedforward; fuzzy LMI control; improved optimal control performance; linearization method
Address
ZY Chen and Ruei-Yuan Wang:School of Science, Guangdong University of Petrochemical Technology, Maoming 525000, Guangdong, China
Yahui Meng:1)School of Science, Guangdong University of Petrochemical Technology, Maoming 525000, Guangdong, China
2)InterNetworks Research Laboratory School of Computing (SOC) University Utara Malaysia 06010 UUM Sintok, Malaysia
Timothy Chen:California Institute of Technology, Pasadena, CA 91125, USA
Abstract
This paper proposed a new self-centering brace (SCB), which consists of four post-tensioned (PT) high strength
steel strands and energy absorbing steel plate (EASP) clusters. First, analytical equations were derived to describe the working
principle of the SCB. Then, to investigate the hysteretic performance of the SCB, four full-size specimens were manufactured
and subjected to the same cyclic loading protocol. One additional specimen using only EASP clusters was also tested to
highlight the contribution of PT strands. The test parameters varied in the testing process included the thickness of the EASP and
the number of EASP in each cluster. Testing results shown that the SCB exhibited nearly flag-shape hysteresis up to expectation,
including excellent recentering capability and satisfactory energy dissipating capacity. For all the specimens, the ratio of the
recovered deformation is in the range of 89.6% to 92.1%, and the ratio of the height of the hysteresis loop to the yielding force is
in the range of 0.47 to 0.77. Finally, in order to further understand the mechanism of the SCB and provide additional information
to the testing results, the high-fidelity finite element (FE) models were established and the numerical results were compared
against the experimental data. Good agreement between the experimental, numerical, and analytical results was observed, and
the maximum difference is less than 12%. Parametric analysis was also carried out based on the validated FE model to evaluate
the effect of some key parameters on the cyclic behavior of the SCB.
Key Words
cyclic testing; hysteresis; recentering; self-centering brace; simulation
Address
Jiawang Liu and Canxing Qiu:Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education, Beijing University of Technology, Beijing 100124, China
Abstract
Owing to the obstruction of section steel on the moisture diffusion in concrete, the existing shrinkage prediction
models overestimate the time-dependent deformation of steel reinforced concrete (SRC) columns, particularly for the SRC
columns with enclosed section steels. To solve this issue, this study deals with analytical and experimental studies on the drying
shrinkage for this type of column. First, an effective method for predicting the drying shrinkage of concrete based on finite
element model is introduced and two crucial parameters for simulation of humidity field are determined. Then, the drying
shrinkage of SRC columns with enclosed section steels is investigated and two modified parameters, which depend on the
ambient relative humidity and the ratio of section steel size to column size, are introduced to the B3 model. Finally, an
experiment on the shrinkage deformation of SRC columns with enclosed section steels is conducted. Comparing the predicted
results with the experimental ones, it demonstrates that the modified B3 model is quite reasonable.
