Applied Mechanics and Materials Vols. 405-408

Abstract: Considering the influence of dynamic interaction between soil and structure, a finite element analysis model of nonlinear dynamic interaction of hinge type slope is established. Then, numerical simulation towards its seismic response has been carried out. Analysis on stress, acceleration and response characteristics of relative horizontal displacement under different seismic oscillation are conducted. Whose results represent that when at the same intensity and spectrum of earthquake motion, the maximum dynamic stress in the middle and upper part of slope is larger while the acceleration and horizontal displacement of the top and bottom is higher. If under earthquake motion with the same intensity and different spectrum, the dynamic response of slope under Loma Prieta wave is larger than that under Kobe wave. Considering the seismic response characteristics of slope, its top and bottom are weak areas. Therefore, attention should be paid to these places in seismic design, same emphasis should also be given to the middle and middle-upper part.

Abstract: A nonlinear procedure for coupled elastoplastic analysis of the dam seismic stability was presented in this paper. The soil nonlinear dynamic behavior was modeled using by a multiple yield surface model based on the numerical framework of u-p formulation. The strength reduction method was used to determine the factor of safety of dam slope and the location of failure surface. A case study of a 293.5 m high clay core rockfill dam was used to demonstrate the application of the method. Based on the computed results, it is founded that the maximum acceleration amplification coefficient is 1.72, which is almost 20% less than that obtained from the equivalent linear analysis. The most dangerous slip surface was at the shallow zone of the lower part of the upstream slope, which was different from the predicted location from the equivalent linear analysis. The earthquake induced pore water pressure and permanent deformation were also studied in detail.

Abstract: Based on the energy-based design approach, variation of seismic dissipation energy with structural properties is investigated by using the SDOF model and the trilinear constitutive. The influence of structural ductility on hysteretic energy, damping energy, hysteretic energy ratio and damping energy ratio is investigated, and the evolution trend of hysteretic and damping energy spectra with ductility ratios and damping ratios is examined for structures subjected to the north south component of El Centro, the Imperial Valley, California earthquake of May 18, 1940.

Abstract: The failure shaking table model test of mass concrete structures is an important basis for understanding to the actual failure of structures. This paper derived all kinds of similar scales between model and prototype in nonlinear dynamic shaking table test, and constructed the reduced scale nonlinear numerical simulation model. The numerical results show that the failure of model and prototype matches the nonlinear similarity theory. Besides, the effect of the characteristics of ground motion was studied and it cannot be ignored to ensure the accuracy of the test.

Abstract: t is a basal task for the right estimation of groundwater runoff process in hydrological computation and hydrological forecasting. Because of the complicated hydrological process of underlying surface and the spacial variability in hilly area, the runoff yield process of groundwater is difficult to describe. This paper, for simulating the runoff yield process which mainly comes from groundwater, from deducing the underlying infiltration equation, stratifies the different conditions of underlying surface firstly, based on the water budget theory. And then, it forms a new system of methods to computing stratified runoff yield, according to J. C. I. Dooge linear system theory and Gardner. W. R. storage outflow equation theory. This method has a favorable effect to checking actual computations and nicer development and application future to simulating the runoff yield process which mainly comes from groundwater.

Abstract: Since the Puyang River in Zhejiang province is easily influenced by tidal backwater of Qiantang River, its design flood level also fluctuates with topographical change of Qiantang River. The topography of Qiantang River has taken place considerable change by climate changes and human activities in recent years, and it had caused flood level of Wenyan station obvious rise from 0.22m to 0.89m, which produces great impact on flood level of Puyang River. This paper adopted the two-dimension numeral model to simulate the impact on flood level of the Puyang River which is caused by tidal backwater of Qiantang River. The results indicate that flood levels of Meichi satiation rise 3-30cm, and which of Linpu satiation rise 4-76cm when they respectively encounter with flood of Qiantang River from once every 100 years to once every 5 years. From the results, we can see the change of topographical of Qiantang River in recent years produces great impact on flood level of the Puyang River.

Abstract: The wandering reach of Zhang River is improved and regulated during the period 1995-2000. However, after that uncontrolled flow still digress from the control of the river banks, endangering the embankment. This project proposes constructing a canalizing the main course of the river, which could in a short time transform the wandering reach into a bending one. This project would form a compound cross-section of river, consisting the narrow canal and the wide open river beach. This project would easily constrain the main current of river, stabilize the flow regime, and ensure the safety of the embankment. Besides, the hardened and canalized river course would alleviate sediment load to the downstream reach.

Abstract: t is analyzed of the effect of the bed form change on the cross section flow measurement and calculation in the flume with the sand ripple bed or smooth bed. The reason is researched that the flow measurement error is caused by the river bed ripple. The Correction method is analyzed under the condition of different discharge and riverbed morphology. So the support is provided in order to improve the physical model discharge measurement accuracy.

Abstract: This paper illustrated the drought resistance strategy, analyzed the profile, characteristics, development tendency and the cause of the drought in Guizhou Province. And the paper analyzed the major measures and achievements of the drought resistance emphatically to provide a reference basis for Guizhou drought resistance.

Abstract: A variational inequality formulation method to define the free surface of fracture network was given, related formulas were deduced and the Finite Element Method was used to solve the equations. By computing, the following conclusions were gotten, that is the variational inequality formulation method to solve unconfined seepage in 3 dimensional fracture network of rock mass is possible, and had a better numerical stability and much less mesh-depenciency.