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Guo B.,China Coal Research Institute | Guo B.,Zhejiang University | Han Y.,China CTDI Engineering Corporation | Gong X.-N.,Zhejiang University | Lu M.-M.,China University of Mining and Technology
Shenzhen Daxue Xuebao (Ligong Ban)/Journal of Shenzhen University Science and Engineering | Year: 2010

The nonlinear consolidation of sand foundation with both horizontal and vertical drainage was analyzed. Three types of variation patterns of the horizontal permeability of soil in the smear zone, including the constant distribution pattern, the linear distribution pattern and the parabolic distribution pattern were considered. Based on the characteristics mentioned above, analytical solution was obtained for this type of consolidation problem. Moreover, the nonlinear consolidation behavior of sand drain foundation was investigated. The results show that the consolidation rate of the foundation with both radial and vertical drainage is faster than the one with only radial drainage. The larger the value of radius ratio is, the smaller their difference is. The overall average degree of consolidation of foundation in terms of pore pressure is unequal to that in terms of strain, the former being always smaller than the later. The consolidation rate is at its maximum for the parabolic distribution pattern, and is at its minimum for the constant distribution pattern whereas the one for the linear distribution pattern is in the mean. When the soil's compressive index is less than the permeability index, the consolidate rate predicted by the present solution is higher than that determined by using the linear consolidate theory. When the soil's compressive index is greater than the permeability index, the present solution always gives a lower consolidation rate than the linear consolidate theory does. The larger the loading is, the faster the consolidation rate is. Source

Chen Z.,Chongqing University | Zhang H.,Chongqing University | Zhang H.,China CTDI Engineering Corporation | Chen F.,Hunan Provincial Architectural Design Institute
Tumu Jianzhu yu Huanjing Gongcheng/Journal of Civil, Architectural and Environmental Engineering | Year: 2013

The wind pressure time-history records of the annular cantilever roof were obtained by the synchronous wind tunnel test on a rigid model of a stadium. Considering the influence of the vortex shedding, the correlation coefficient and coherence function of along-wind and cross-wind points were analyzed to get the characteristics of the external fluctuating pressure correlation of the stadium's cantilever roof. The coherence function curves were fitted and the related coherence function was presented. Compared with the classical coherence function models, the present coherence function has the same form and a higher fitting accuracy for the cantilever roof. Source

Wu G.X.,Chongqing Jiaotong University | Li Q.J.,Chongqing Jiaotong University | Cheng G.Y.,China CTDI Engineering Corporation
Applied Mechanics and Materials | Year: 2013

A road's ecological environmental quality index data for years is a time-series, and accurate prediction by exploring the changing rule of the time series is significant for future environmental protection. For this end, based on time series analysis, this paper firstly carries out steady analysis and random test pretreatment for the eco-environment quality index (EQI) data collected. Next, an ARMA model is established by pattern recognition, established bands and parameter estimation, and then verified by the data collected in recent years. Finally, the ARMA model is used to predict the future EQI values. This research will provide effective guidance to the eco-environmental protection along the road. © (2013) Trans Tech Publications, Switzerland. Source

Zhang D.,Harbin Institute of Technology | Dong Y.,Huaqiao University | Wu Y.,China CTDI Engineering Corporation
Huazhong Keji Daxue Xuebao (Ziran Kexue Ban)/Journal of Huazhong University of Science and Technology (Natural Science Edition) | Year: 2012

An improved virtual work method was proposed to calculate the ultimate load-carrying capacity of one-way concrete slabs under uniformly distributed load at large displacements, and its derivation was based on the classical yield-line theory. The work, which caused by the extension of steel reinforcements at the sections of plastic hinge line under large displacements, was added in the method. Six one-way slabs with three types of edge conditions were tested to validate the method. Then the theoretical predictions by the method were compared with experimental results. It is shown that the failure mode of the test slabs subjected to large displacement is almost identical with that assumed in the classical yield-line theory. The slabs can carry test load steadily due to the tensile membrane action, even when their displacements reach 1/15 of the span-length. The predicted load-carrying capacity of the method is no more than 10% error compared with the test results, and it shows good accuracy. Source

Jiang Y.,Chongqing Jiaotong University | Bai H.,China CTDI Engineering Corporation
Applied Mechanics and Materials | Year: 2012

The basic theory of fast multipole virtual boundary element method (VBEM) is discussed through expanding the fundamental solution, and the algorithm can make the complexities of operation and memory about solution of the equations to be of linear proportion to the freedoms of the problem. Numerical examples are presented to demonstrate the feasibility, accuracy and efficiency of the method. At the same time, the relationships between the order for expansion and the storage capacity, computing time, precision are analyzed, and the influence of boundary points in the leaf to the calculation efficiency is discussed. The corresponding reference value is put forward for the convenience of engineering application. © (2012) Trans Tech Publications. Source

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