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Wang X.,Chongqing Jiaotong University | Chen B.,Zhejiang University | Sun D.,China Earthquake Administration | Wu Y.,Bureau of Public Works of Shenzhen Municipality
Scientific World Journal | Year: 2014

Through the wind velocity and direction monitoring system installed on Jiubao Bridge of Qiantang River, Hangzhou city, Zhejiang province, China, a full range of wind velocity and direction data was collected during typhoon HAIKUI in 2012. Based on these data, it was found that, at higher observed elevation, turbulence intensity is lower, and the variation tendency of longitudinal and lateral turbulence intensities with mean wind speeds is basically the same. Gust factor goes higher with increasing mean wind speed, and the change rate obviously decreases as wind speed goes down and an inconspicuous increase occurs when wind speed is high. The change of peak factor is inconspicuous with increasing time and mean wind speed. The probability density function (PDF) of fluctuating wind speed follows Gaussian distribution. Turbulence integral scale increases with mean wind speed, and its PDF does not follow Gaussian distribution. The power spectrum of observation fluctuating velocity is in accordance with Von Karman spectrum. © 2014 Xu Wang et al.


Liu Q.,Bureau of Public Works of Shenzhen Municipality | Fu X.,Shenzhen University | Sun Z.,China Overseas HUAYI Urban Planning and Design Co.
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2011

One of the much concerned problems in seismic engineering is to seek reasonable and efficient method to obtain earthquake action and its effects on structures of various material damping characteristics in components. Currently, the most often used complex mode superposition method and direct integration method to calculate transient earthquake responses are developed based on viscous damping assumption. Viscous damping assumption has disadvantages. For example, the earthquake effects of high frequencies may be underestimated since the energy dissipation is related to excitation frequencies according to the viscous damping assumption. Furthermore, since the damping matrix interacts with results of complex mode analysis, results of above mentioned methods are not unique and the rationality of the results is difficult to be determined. Complex damping assumption can avoid disadvantages of viscous damping assumption, though usually it brings out complex form results which may be inconvenient to use. A complex mode superposition method based on the complex damping assumption which resolves directly in physics space and obtains unique results was put forward. It is proved that the new method is more efficient than that based on the viscous damping assumption. Compared with results of the new method, results of widely used equivalent damping ratio method are unreasonable. In addition, method for calculating modal effective mass factor which can be used to determine reasonable number of superimposed modes based on the complex damping assumption was also put forward.


Liu Q.,Bureau of Public Works of Shenzhen Municipality | Fu X.,Shenzhen University
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2011

One of the most concerned problems in seismic engineering is to seek reasonable and efficient method to obtain earthquake action and its effects on structures of different material damping characteristics in components. In recent years, a method called response spectrum CCQC (Complex Complete Quadratic Combination) based on viscous damping assumption has been put forward and proved to be in general a satisfactory method to solve the above problem. But viscous damping assumption has disadvantages, e.g., the energy dissipation is related to excitation frequencies, so that earthquake effects of high frequencies may be less than reality. Complex damping assumption can avoid the disadvantages of the viscous damping assumption, but usually it brings out complex form results which may be inconvenient to use. Based on assumptions of complex damping and stationary random excitation process, a pseudo-excitation method was used to acquire a new expression of complex complete quadratic combination method (OCCQC) and its simplified form according to the traditional approach (TCCQC). Results of both expressions are in real format, and can be easily used in engineering. Comparing with the results of stationary random vibration analysis, the results of OCCQC were in good agreement, while the results of TCCQC are much less, which shows that OCCQC is more rational than TCCQC. Furthermore, practical method for truncation of modes was also put forth by way of modal effective mass factor.


Guo Y.,Tsinghua University | Dou C.,Tsinghua University | Wang Y.,Tsinghua University | Cao P.,Hohai University | And 5 more authors.
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2010

A new type of structural system named as 'single-layer folded-plane spatial reticulated structure' was adopted in the steel roof of main stadium in Shenzhen Universiade Sport Center. An experimental investigation of integral structural scaled model was carried out. The loading with a 'pre-stacked self-balancing loading system' and the scheme of 'stretching in batch and grade using manual chain hoists', 'controlling by displacement firstly-then adjusting by inner force', was conducted to study the stiffness variation and load-carrying capacity of the model. The weak regions and failure mechanism were observed and investigated accordingly. Test results agree with analytical results by FEM, indicating that single-layer folded-plane spatial reticulated structure has enough integral stiffness and safety factor, however the load-carrying capacity is determined by individual members in high tension stress. The connection of members under high tension force and bending moment with joints in shoulder apex is the weak region of the whole structure, therefore the regions should be much concerned and the welding quality should be controlled strictly during construction.


Liu Q.,Shenzhen General Institute of Architectural Design and Research Co. | Zhang J.,Shenzhen General Institute of Architectural Design and Research Co. | Guo M.,Shenzhen General Institute of Architectural Design and Research Co. | Liu C.,Shenzhen General Institute of Architectural Design and Research Co. | And 3 more authors.
Jianzhu Jiegou Xuebao/Journal of Building Structures | Year: 2011

The steel roof of the stadium adopted the single-layer folded-plane lattice shell structure in Shenzhen Universiade Sports Centre. The maximam cantilevered span is 68.4 meter. The structure has 20 spherical hinge supports, causing stability problems and many technical challenges beyond code. To achieve a kind of structure that is safe, economical and excellent capacity on wind and seismic resistance, the overall structural dynamic and static behavior, support reactions before and after the architectural shape adjustment and the circular beam addition. The results indicate that the structural system is stable and safe with good wind and seismic resistance. Adjusting architectural shaper and adding circuit beam can reduce the period and wind vibration effect, improve the structural stiffness and the overall damping, reduce support circular force, improve stress concentration, improve the use of materials and achieve good structural performance.

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