Showing papers by "Qiusheng Li published in 2013"
TL;DR: In this paper, the authors conducted deep seismic-reflection surveying across the Jurassic Daba Shan thrust belt of central China to investigate how and why the continued convergence between north and south China lasted ∼50 m.y. after the Triassic closure of their intervening oceans.
Abstract: We conducted deep seismic-reflection surveying across the Jurassic Daba Shan thrust belt of central China to investigate how and why the continued convergence between north and south China lasted ∼50 m.y. after the Triassic closure of their intervening oceans. Our study, together with surface geology, gravity surveying, and magnetic observations, indicates widespread occurrence of mafic plutons below the Daba Shan thrust belt. We propose that subduction of dominantly eclogitized mafic crust of northern south China provided the driving force for continued convergence between north and south China after ocean closure.
113 citations
TL;DR: In this article, the authors presented the field measurement results of dynamic characteristics and wind-induced responses of a 420m high tall building in Hong Kong during the passage of typhoons.
57 citations
TL;DR: In this paper, the authors investigated the wind loads on a tall building and the wind speed up factors in the tunnels for wind-power generation based on wind tunnel tests and wind climate data analysis.
55 citations
TL;DR: In this article, a 2D map of Moho topography was provided by combining their crustal thickness to that from permanent stations, active seismic and OBS offshore profiles, which is consistent with previous studies and shows a crust that thins coastward and southwestward in the rate of ~ 1.5 km per 100 km.
53 citations
TL;DR: In this article, the authors present an investigation of wind characteristics over several typical terrain conditions based on a 6 years' database from four surface meteorological stations in Hong Kong, which mainly include turbulence intensity, gust factor, spectra and turbulence integral length scale.
48 citations
TL;DR: In this article, an active tuned mass damping (ATMD) system was used to suppress the wind-induced vibrations of a super-tall building during a typhoon, and the building's acceleration responses were well confined within the range stipulated in the International Standards Organization for serviceability concerns.
Abstract: SUMMARY
This paper presents observations on the dynamic properties and wind-induced response characteristics of a 492-m-high building installed with an active tuned mass damping (ATMD) system during a typhoon. Damping ratios, natural frequencies, and wind-induced vibrations of the super-tall building with/without the operation of the ATMD system are investigated. Field measurement results show that the ATMD system functioned efficiently for the suppression of the wind-induced vibrations of this super-tall building, and the building's acceleration responses were well confined within the range stipulated in the International Standards Organization for serviceability concerns. A modified time-weighted random decrement operator is proposed for estimation of damping ratio, which is able to provide more reasonable estimations than unmodified form under nonstationary conditions. In addition, extreme responses of this building under the typhoon are studied using the crossing method and the generalized extreme value model. The main objective of this study is to investigate the effectiveness of the ATMD system and the performance of the actively controlled high-rise structure under typhoon condition to assess the benefits gained from the application of the vibration control technique. Copyright © 2013 John Wiley & Sons, Ltd.
37 citations
TL;DR: In this paper, a detailed three-dimensional P-wave velocity (Vp) structure of the crust and upper mantle down to 400 km depth was determined by applying teleseismic tomography to 6869 high-quality Pwave arrival times.
30 citations
TL;DR: In this article, the vertical profiles of horizontal mean wind speed and direction based on the synchronized measurements from a Doppler radar profiler and an anemometer during 16 tropical cyclones at a coastal site in Hong Kong were investigated.
Abstract: This paper investigates the vertical profiles of horizontal mean wind speed and direction based on the synchronized measurements from a Doppler radar profiler and an anemometer during 16 tropical cyclones at a coastal site in Hong Kong. The speed profiles with both open sea and hilly exposures were found to follow the log-law below a height of 500 m. Above this height, there was an additional wind speed shear in the profile for hilly upwind terrain. The fitting parameters with both the power-law and the log-law varied with wind strength. The direction profiles were also sensitive to local terrain setups and surrounding topographic features. For a uniform open sea terrain, wind direction veered logarithmically with height from the surface level up to the free atmospheric altitude of about 1200 m. The accumulated veering angle within the whole boundary layer was observed to be 30o. Mean wind direction under other terrain conditions also increased logarithmically with height above 500 m with a trend of rougher exposures corresponding to lager veering angles. A number of empirical parameters for engineering applications were presented, including the speed adjustment factors, power exponents of speed profiles, and veering angle, etc. The objective of this study aims to provide useful information on boundary layer wind characteristics for wind-resistant design of high-rise structures in coastal areas.
28 citations
TL;DR: In this article, a parallel fluid-structure interaction method based on socket parallel architecture was established and combined with the methods and models of large eddy simulation developed by authors recently, the results obtained show that the proposed method and models is capable of performing high-Reynolds number LES and high-efficiency two-way coupling between detailed fluid dynamics computing and solid structure dynamics computing so that the detailed wind induced responses for high-rise buildings can be resolved practically.
Abstract: With more and more high-rise building being constructed in recent decades, bluff body flow with high Reynolds number and large scale dimensions has become an important topic in theoretical researches and engineering applications. In view of mechanics, the key problems in such flow are high
Reynolds number turbulence and fluid-solid interaction. Aiming at such problems, a parallel fluid-structure
interaction method based on socket parallel architecture was established and combined with the methods and models of large eddy simulation developed by authors recently. The new method is validated by the full two-way FSI simulations of 1:375 CAARC building model with Re = 70000 and a full scale Taipei101 high-rise building with Re = 1e8, The results obtained show that the proposed method and models is
potential to perform high-Reynolds number LES and high-efficiency two-way coupling between detailed fluid dynamics computing and solid structure dynamics computing so that the detailed wind induced responses for high-rise buildings can be resolved practically.
23 citations
TL;DR: The SinoProbe02 North China seismic experiment consisted of three seismic recording efforts along a 450 km long profile as discussed by the authors, where the recording of seismic waves from 8 explosions was conducted in 4 deployments of 300 Texan recorders with station spacings of 1.5 km.
9 citations
TL;DR: In this paper, a finite element model (FEM) of a bridge structure was established based on the design blueprint and was updated using periodic inspection or structural health monitoring (SHM) data.
Abstract: An approach to analyzing the evolution of the failure patterns and ultimate load-carrying capacity of prestressed concrete (P.C.) cable-stayed bridges based on a mixture of inspection and structural health monitoring (SHM) techniques is proposed. Firstly, a finite element model (FEM) of a bridge structure was established based on the design blueprint and was updated using periodic inspection or SHM data. The relationship between girder section axial force and bending moment bearing capacity was analysed with the consideration of damage and performance deterioration. Then, using vehicle loading patterns, which can be obtained from SHM data or bridge design codes, vehicle loads are applied to the updated FEM to determine the internal forces in bridge components. Finally, the locations where loads exceed the bearing capacity of components are set as plastic hinges to model the nonlinear behaviour of the structure. This procedure is repeated with the load increasing continuously up to the ultimate load-carryi...
TL;DR: Based on the wind tunnel test of rigid model of a tall building, the wind pressure distribution on the building with interfering buildings around it has been researched, the contours of the mean and fluctuate wind pressure coefficients have also been presented as mentioned in this paper.
Abstract: Most tall buildings are constructed in the prosperous center of large cities, where is inevitable to be surrounded by many interfering buildings. Wind interference effects among buildings should not be neglected. Therefore, it is necessary to investigate wind interference effects on such tall buildings. Based on the wind tunnel test of rigid model of a tall building, the wind pressure distribution on the building with interfering buildings around it has been researched, the contours of the mean and fluctuate wind pressure coefficients have also been presented. It has been found that shielding effect and channeling effect are significant in the wind interference effects on building. Wind pressure coefficients on side wall and leeward wall of a upstream building may be dramatically changed in case the wake boundary of the upstream building is interfered. The conclusions might be used as reference to structural design and plan.
TL;DR: In this paper, the axial compressive experiments of six T-shaped concrete-filled steel tubular stub columns, five with and one without steel bone, were carried out, and the effects of tube confining factor, bone indicator, and axial compression behavior of the columns were analyzed.
Abstract: Concrete-filled steel tube structure is one of the important load-bearing systems of modern high-rise building.The research indicate that concrete-filled steel tube structure has a good static and seismic performance,and concrete-filled steel tubular component is always used as axial compression and compression-bending component.However,what about the mechanical behavior of this combinational structure (concrete-filled steel tubular columns with steel bone built-in)? So there is a new type of special-shaped cross-section of composite structure,that is the T-shaped concrete-filled steel tubular columns with steel bone.The research about this structure is less throughout domestic and foreign.So the axial compressive experiments of six T-shaped concrete-filled steel tubular stub columns, five with and one without steel bone, were carried out. The effects of tube confining factor, bone indicator on the axial compressive behavior of the columns are analyzed. Experimental results indicate that the ultimate strength of the T-shaped steel tubular stub columns with steel bone increases, can be increased by 71.7%.And that the setting of steel bone improves the confinement of the concrete core, delays or even avoids the local buckling of the steel tube before the stress attains the yield strength. The ductility of the columns is also greatly increased.And at last in this paper, use of static equilibrium conditions and limit yield conditions,and in reference to literature[1],the calculation equation of compression capacity of this combinational column is derived.Moreover,calculation results according to the formula in this paper are in good agreement with the experimental results. The conclusions might be used as reference to structural design and plan.
TL;DR: In this article, a modified wall function is derived based on flow over a plate at zero-pressure gradient, instead of on the basis of asymptotic formulations, which can save significant computational costs compared to other near-wall flow treatment strategies.
Abstract: Wall functions have been widely used in computational fluid dynamics (CFD) simulations and can save significant computational costs compared to other near-wall flow treatment strategies. However, most of the existing wall functions were based on the asymptotic characteristics of near-wall flow quantities, which are inapplicable in complex and non-equilibrium flows. A modified wall function is thus derived in this study based on flow over a plate at zero-pressure gradient, instead of on the basis of asymptotic formulations. Turbulent kinetic energy generation (GP), dissipation rate (e) and shear stress (tw) are composed together as the near-wall expressions. Performances of the modified wall function combined with the nonlinear realizable k -e turbulence model are investigated in homogeneous equilibrium atmosphere boundary layer (ABL) and flow around a 6 m cube. The computational results and associated comparisons to available full-scale measurements show a clear improvement over the standard wall function, especially in reproducing the boundary layer flow. It is demonstrated through the two case studies that the modified wall function is indeed adaptive and can yield accurate prediction results, in spite of its simplicity.
TL;DR: In this article, the mean, fluctuating (RMS) and peak pressure coefficients, the local shape coefficient distributions on fish-shaped roofs were presented and discussed, and it was found that negative pressures (suctions) occurred on most areas on the roofs, and high negative pressure coefficients occurred on the eaves and cantilevered roof parts.
Abstract: Wind tunnel tests of 1:100 rigid model of fish-shaped roof structures were carried out. The mean, fluctuating (RMS) and peak pressure coefficients, the local shape coefficient distributions on fish-shaped roofs were presented and discussed. It was found that negative pressures (suctions) occurred on the most areas on the roofs, and high negative pressure coefficients occurred on the eaves and cantilevered roof parts. When wind flows blew along the corridors under the roofs, the flows enhanced suctions on the surfaces of the roofs, and the suctions on the lower surface were greater than those on the upper surfaces, positive pressures occurred on that area after superposition of wind actions on the two sides. The roof eaves and regions above the corridors experienced the worst RMS pressure coefficients and the worst minimum pressure coefficients. The distribution characteristics of the worst RMS and minimum pressure coefficients were found to be quite similar to those of the mean pressure coefficients. The results obtained from the experimental investigation are expected to be useful in the wind-resistant design of complex roof structures in typhoon-prone regions.
TL;DR: In this article, a cable-stayed bridge model was made based on the design drawings of Shandong Binzhou Yellow River Highway Bridge (BZB) and detailed model tests were conducted.
Abstract: A cable-stayed bridge model was made based on the design drawings of Shandong Binzhou Yellow River Highway Bridge (BZB) and detailed model tests were conducted. In the tests, the cable damage effects on the loading behavior and dynamic performance of the bridge model were studied by considering different cable damages' locations, different numbers of damaged cables, and different damaged levels of cables etc. The experimental results revealed that the cable damages may significantly affect the internal forces of other cables and the stress distributions of the girders; however, they have less influence on the natural frequencies of the bridge model. In parallel with the model tests, a finite element model of the bridge structure has been established. Numerical analysis for the bridge model with cable damages was carried out to validate the experimental results and explain the phenomena observed in the model tests.
TL;DR: In this article, a design guideline for wind-resistant design of atrium facades was proposed, and the results predicted by the proposed guideline were in good agreement with those from the wind tunnel tests, indicating that the suggested guideline can be used in engineering applications.
Abstract: Wind tunnel test of 1:500 rigid model of tall building with atrium was carried out. Based on the experimental results, characteristics of wind pressures on atrium facades and wind loads on the structure were investigated in detail. The results show that the formation of flow separation on the building top plays a critical role in the generation of wind pressures on the atrium facades. Meanwhile, wind pressure coefficient distributions on the atrium facades are found to be relatively uniform. Moreover, the horizontal and vertical correlations of pressure coefficient exhibit high at most locations on atrium facades. With the increasing of the opening ratio, the mean wind pressure coefficients first decreased and then stabilized, and the fluctuating wind pressure coefficients first decreased and then increased. A design guideline for the wind-resistant design of atrium facades was proposed, and the results predicted by the proposed guideline were in good agreement with those from the wind tunnel tests, indicating that the proposed guideline can be used in engineering applications. When the opening ratio is no more than 5.33%, the effect of the facade pressures within the atrium on the wind loads on the structure can be ignored. For such cases, the wind-resistant design for a tall building with atrium can refer to that of a similar shape tall building without atrium.
TL;DR: In this article, the results of wind loads acting on the large-span roof structure of the Shenzhen New Railway Station (SNRS) were analyzed in a wind tunnel test, where wind-induced pressures including mean and fluctuating components were measured from the roof of a 1:200 scale SNRS model under suburban boundary layer wind flow configuration.
Abstract: The Shenzhen New Railway Station (SNRS) has roof dimensions of 450 m long and 408 m wide. This paper presents the results of wind loads acting on the large-span roof structure. In the wind tunnel test, wind-induced pressures including mean and fluctuating components were measured from the roof of a 1:200 scale SNRS model under suburban boundary layer wind flow configuration in a boundary layer wind tunnel of HD-2 at Hunan University. Based on the data obtained simultaneously from the wind tunnel tests, the distributions of the mean and fluctuating wind pressure coefficients and the characteristics of probability density functions of wind pressures of typical pressure taps were analyzed in detailed. The outcomes of the experimental study indicate that: (1) The maximum mean negative wind pressure coefficients on the roof occur at the windward leading edge region, where the maximum fluctuating wind pressure coefficients occur also in this region; (2) There are some differences of the maximum mean negative wind pressure coefficients and RMS wind pressure coefficients under conditions with different number of trains inside the station, but such effects on the overall pressure distributions on the whole roof are negligible; (3) There are clearly negative skewed distributions for some pressure taps at the windward leading roof edge and much longer negative tails are observed, which follow Non-Gaussian distributions. The results presented in this paper are expected to be of considerable interest and of use to researchers and professionals involved in designing complex long-span roof structures.