Advances in Structural Engineering
1369-4332
2048-4011
Mỹ
Cơ quản chủ quản: SAGE Publications Inc.
Lĩnh vực:
Building and ConstructionCivil and Structural Engineering
Các bài báo tiêu biểu
Hybrid fibre-reinforced polymer–timber thin-walled structural members The increasing interest in timber as a sustainable construction material has led to the development of a new type of structures referred to as ‘hybrid fibre-reinforced polymer–timber thin-walled structures’. In these structures, thin layers of fibre-reinforced polymer are combined with timber veneers to create high-performance, lightweight and easy-to-construct structural members. This new type of structural members harnesses the orthotropic properties of both timber and fibre-reinforced polymer by appropriately orientating material fibre directions for optimal composite properties as well as efficient thin-walled cross-sectional shapes. Hybrid fibre-reinforced polymer–timber thin-walled members can be used in many applications such as load-bearing walls, roofs, floor panels and bridge decks. This article describes several novel hybrid fibre-reinforced polymer–timber structural member forms and presents results from a preliminary experimental investigation into the compressive behaviour of hybrid fibre-reinforced polymer–timber wall panels. A comparison of behaviour between a hybrid fibre-reinforced polymer–timber wall panel and a pure timber wall panel is presented to show that the hybrid fibre-reinforced polymer–timber system significantly outperforms the pure timber system in terms of both load resistance and axial strain at failure.
Tập 21 Số 9 - Trang 1409-1417 - 2018
Modeling the Amount of Steel Corrosion at the Cracking of Concrete Cover This article tries to contribute to quantify the amount of steel corrosion at the cracking of concrete cover. The amount of steel corrosion when the concrete cover cracks, is a key factor in the life of concrete structures. During the time between steel depassivation and concrete cover cracking, the process of steel corrosion develops in three stages: free expansion of the corrosion products, stress initiation of the concrete cover, and cracking of the concrete cover. A concrete cracking model is presented here to estimate the total amount of steel corrosion at the onset of the cracking of the concrete cover. This model is applied to some test results reported by other researchers. The amount of steel corrosion predicted by the proposed model when cracking of the concrete cover occurs is in agreement with the experimentally observed results.
Tập 9 Số 5 - Trang 687-696 - 2006
Initial Stiffness of Reinforced Concrete Columns with Moderate Aspect Ratios The estimation of the initial stiffness of columns subjected to seismic loadings has long been a matter of considerable uncertainty. This paper reports a study that is devoted to addressing this uncertainty by developing a rational method to determine the initial stiffness of RC columns when subjected to seismic loads. A comprehensive parametric study based on a proposed method is initially carried out to investigate the influences of several critical parameters. A simple equation is then proposed to estimate the initial stiffness of RC columns. The applicability and accuracy of the proposed method and equation are then verified with the experimental data obtained from literature studies.
Tập 15 Số 2 - Trang 265-276 - 2012
Seismic Performance Upgrading for Underground Structures by Introducing Shear Panel Dampers A new method of upgrading seismic performance for underground structures is proposed in this paper. Both single-story and double-story underground subway stations are studied. Using the famous single-story Daikai Station model, by which the reliability of the numerical model is verified, seismic efficiency of Shear Panel Damper (SPD) in underground structures is proven. Then, in order to design appropriate and efficient SPDs for underground structures, strength ratio, one of the design parameters, is employed to investigate the seismic performance of structures. The recommended optimum range of strength ratio is given. Afterwards, typical double-story three-span stations with different SPDs layout forms are analyzed to figure out the optimal placement of SPDs. And some interesting conclusions are obtained, which may provide a convenient way to design SPDs in multi-story underground structures.
Tập 17 Số 9 - Trang 1343-1357 - 2014
Seismic performance of framed underground structures with self-centering energy-dissipation column base For the development of underground structures toward large-scale, long-span, and complex structural styles, comprehensive seismic mitigation and controlling measures that consider reducing internal forces together with controlling lateral structural deformation and upgrading energy consumption are significant for improving seismic performance and enhancing resilience of underground structure. For this purpose, a self-centering energy-dissipation column base, which originated from the concept of earthquake resilient structures in aboveground space, is proposed for the framed underground structures in this study. To verify the effectiveness of self-centering energy-dissipation column base, three-dimensional time history analyses are conducted on a single-story double-span subway station. The analysis results show that the self-centering energy-dissipation column base effectively decreases the internal forces of central column and the peak and residual values of story drift and column drift are also minimized about 4%–5%. Meanwhile, it is found that a cyclic opening–closing exists at the column base during an earthquake and the uplift of column returns to zero at the end of the earthquake. It means the self-centering effect of the column base is achieved as expected. Moreover, replaceable energy-dissipating devices provide supplementary energy dissipation to relieve the development of structural plasticity and the uplift behavior of column base avoids the occurrence of plastic hinge. As a result, the structural damages are effectively reduced after the earthquake.
Tập 22 Số 13 - Trang 2809-2822 - 2019
Wind tunnel tests on the aerodynamic characteristics of vehicles on highway bridges Accurately quantifying the aerodynamic forces acting on vehicles and long-span bridges is critical for assessing the safety of moving vehicles on bridges which are subjected to strong wind. It is necessary to consider the aerodynamic interference between vehicles and the bridge, especially for this with the bluff body section and wind barriers. However, very few investigations have been carried out to find aerodynamic coefficients of vehicles on a bridge with the bluff body section and considering the effect of wind barrier. This article therefore carried out wind tunnel tests to determine aerodynamic coefficients of container truck on a bridge with a π-cross section and wind barriers. The influence of vehicle position in different road lanes of the bridge deck and the aerodynamic interference between vehicles on the aerodynamic characteristics of the vehicle and the bridge are investigated. Different heights and ventilation ratios of wind barrier are taken into consideration to examine variations of aerodynamic coefficients with different wind barriers. Furthermore, the change mechanism in the aerodynamic coefficients of the vehicles is observed by analyzing the wind pressure distribution on the surface of the vehicles. The test results show that the different lane locations of the vehicle affect the aerodynamic coefficients significantly, as well as the aerodynamic interference between vehicles with transverse arrangement or longitudinal arrangement, especially for the side force coefficient. The existence of wind barrier reduces the side force coefficients of the vehicle remarkably. Such effects also vary with the ventilation ratio and height of wind barrier.
Tập 23 Số 13 - Trang 2882-2897 - 2020
Experimental studies on the vortex-induced forces of a 4:1 rectangular cylinder and two typical bridge girders Wind tunnel tests were performed on a 4:1 rectangular (REC) cylinder, a trapezoidal (TRA) girder, and a typical streamlined (STR) box girder to investigate the vortex-induced forces and their spanwise correlations. First, using the free vibration technique, the vortex-induced vibration responses and the Strouhal number were investigated at different Scruton numbers and attack angles. Then, the mean and standard deviations of the vortex-induced pressure coefficients of the three models were analyzed through simultaneous pressure measurements. The power spectral density and the spanwise correlation of vortex-induced pressures at some typical points were also studied. Finally, the spanwise correlations of vortex-induced forces acting on the three models in the cases of different vibration amplitudes and attack angles were investigated. The results show that the attack angle has a significant effect on the vortex-induced pressure distributions for the three types of girders. The second frequency components of the vortex-induced pressure occur near the trailing edge of the upper surface for the three types of sections. The correlation of vortex-induced force decreases with the increase in the oscillation amplitude for the REC model, but becomes larger for the TRA and STR models. With the increase in the attack angle, the spanwise correlations of vortex-induced forces on the three sections become weaker, especially for the REC model.
Tập 23 Số 3 - Trang 399-410 - 2020
Deflection Reliability Analysis of PSC Box-Girder Bridge under High-Speed Railway Loads A high-speed railway (HSR) construction boom has been observed in China during the past few years, in which prestressed concrete (PSC) box-girders are widely used for HSR bridges. Concerns have been raised regarding the long-term deflection of girders under the combined actions of concrete creep, shrinkage, and tendon relaxation, since the time-variant deflection significantly undermines the safety of high-speed trains. This paper presents the time-variant deflection reliability analysis of an existing HSR PSC box-girder bridge, in which a hybrid method, consisting of the response surface (RS) method, the finite element (FE) method and the checking point method (i.e., the JC method), is used. The pre-and post-cracking behaviors of the thin-walled box girder are described by using composite degenerated shell elements with the smeared cracking model and the Hordijk's tension softening relation. In particular, the CEB-FIP model for creep and shrinkage is applied in the finite-element (FE) analyses. By using the probabilistic sensitivity analyses, random variables that significantly affect the time-variant deflection are selected for the reliability calculation. It is found that the deflection reliabilities are high in the early stage of bridge service but decrease rapidly during the first 10 to 20 service years. Higher speed limits result in a significant decrease in deflection reliability indices, which may fall below the target value prior to the expected service life. The proposed methodologies can be used in the design optimization, speed control and making rational maintenance or repair strategies for HSR PSC bridges.
Tập 15 Số 11 - Trang 2001-2011 - 2012
Probabilistic Response Analysis of Cracked Prestressed Concrete Beams In the response analysis of cracked prestressed concrete beams deterministic procedure is insufficient to provide complete information. Probabilistic analysis is a holistic approach to predicting structural responses considering uncertainties in structural and load parameters. This paper proposes an efficient and accurate algorithm to predict responses of cracked prestressed concrete beams with parameter uncertainties. The proposed algorithm integrates the advantages of the response surface method, section curvature method and Monte Carlo simulation. Uncertainties in the structure and load parameters can be taken into account in this algorithm. The algorithm is verified using the Monte Carlo simulation. The proposed algorithm is then used to predict the response of a simply supported prestressed beam with parameter uncertainties. The results show that neglecting the effect of uncertainty in the prestressing force results in a significant underestimation of response statistics of cracked prestressed concrete beams. Finally, the most influential random variables on the response statistics of cracked prestressed concrete beams are identified by using a sensitivity analysis.
Tập 10 Số 1 - Trang 1-10 - 2007
Numerical Study of the Nonlinear Dynamic Behaviour of Reinforced Concrete Cooling Towers under Earthquake Excitation Reinforced concrete cooling towers of hyperbolic shell configuration find widespread application in utilities engaged in the production of electric power. In designing critical civil infrastructure of this type, it is imperative to consider all of the possible loading conditions that the cooling tower may experience. One important loading condition in many nations is that of earthquake excitation, whose influence on the integrity and stability of cooling towers is profound. Previous research has shown that the columns supporting a cooling tower are sensitive to earthquake forces, as they are heavily loaded elements that do not possess high ductility, and understanding the behaviour of columns under earthquake excitation is vital in structural design because they provide the load path for the self weight of the tower shell. This paper presents the results of a finite element investigation of a representative “dry” cooling tower, using realistic horizontal and vertical acceleration data obtained from the recent and widely-reported Tabas, Naghan and Bam earthquakes in Iran. The results of both linear and nonlinear analyses are reported in the paper, the locations of plastic hinges within the supporting columns are identified and the ramifications of the plastic hinges on the stability of the cooling tower are assessed. It is concluded that for the (typical) cooling tower configuration analysed, the columns that are instrumental in providing a load path are influenced greatly by earthquake loading, and for the earthquake data used in this study the representative cooling tower would be rendered unstable and would collapse under the earthquake forces considered.
Tập 9 Số 3 - Trang 433-442 - 2006