Applied Mechanics and Materials Vols. 580-583

Abstract: Based on well-balanced Roe’s approximate Riemann solver, a numerical model is developed for the unsteady, two-dimensional, shallow water flow with variable topographies. In this model, an efficient methods are applied to treat the source terms and to satisfy the compatibility condition on unstructured grids. In the method, different components of the bed slope source term are considered separately and the compatible discretization of the components is presented. The newly developed model is verified against analytical solutions and measured date, with good agreement.

Abstract: A regularization based method of inversely analyzing the material parameters for the gravity dams is presented in this paper. The measured noise of the displacement often leads to the ill-posed solutions of the dam inversion. A least square scheme was adopted for the inverse analysis by using of the displacement measurements, and the L-curve algorithm was proposed to perform the regularization in the inversion computation. The proposed method actually utilizes the sensitivity of the measured displacements with respect to the sub-regional material parameters. Thus a simplified algorithm was developed to calculate the sensitivity coefficients by using the standard finite element procedure. To investigate the effectiveness of the proposed method, the numerical simulations on a concrete gravity dam were carried out. The results demonstrate that the presented method can accurately obtain the material parameters of the dam by using of the inverse analysis, which has the potential for assessing the integrity of the gravity dams.

Abstract: On the basis of summarizing the predecessors' research, based on the contracted depth basic equation mathematical transformation of quadratic parabola shaped sections, the interrelation between dimensionless contracted depth and the dimensionless parameter were analyzed, we obtain the approximate formula for contracted depth in Quadratic parabola shaped channels, it is simpler and accurate, Its maximum relative error are less than 0.12% in the utility range.

Abstract: This study Base on the HuangLianzhou heart beaches and Shejiwang tidal flat of years of evolution, revealing the relationship between HuangLianzhou heart beaches and Shejiawan tidal flat erosion and Waterway conditions, and explore affecting factorsof the waterway poor conditions , which have a guiding significance for the solution to the current problem of the river channel.

Abstract: It is difficult to get a theoretic answer to the water flow load features of high dam flood discharge. Through direct measurement of water flow load features by arranging a surface pressure cell, the complicated point-surface conversion was avoided, and the shock load and surge load features were obtained. For the dam body outlet wall pressure, isolated the fluctuating load applied to the plunge pool floor and the downstream dam surface, the impact of the fluctuating load to the arch dam dynamic response at the flood discharge flow outlet was obtained, and then the equivalent fluctuating load on each discharge flow outlet was obtained by using flow-induced vibration back analysis. The test shows that the energy of the shock load and the surge load mainly centers in a frequency range between 0~1Hz, the shock load is about 2.5-6 times that of the surge load, and the surge load is about 4 times that of the outlet wall pressure.

Abstract: By numerical calculation, it analyzed the seepage effects of plastic concrete cut-off wall in in construction period. On construction period, the seepage flow from inside of channel to outside at unit length is 0.753m³/h. The seepage flow from under plastic concrete cut-off wall is 0.646m³/h which is 85.79% of total seepage flow. Under certain condition on operation period, the seepage flow from inside of channel to outside at unit length is 0.394m³/h. The seepage flow from under plastic concrete cut-off wall is 0.358m³/h which is 90.86% of total seepage flow. Under another condition on operation period, the seepage flow from inside of channel to outside at unit length is 0.249m³/h. The seepage flow from under plastic concrete cut-off wall is 0.236m³/h which is 94.78% of total seepage flow. In It showed the plastic concrete cut-off wall has obvious effect.

Abstract: In order to comprehensively analyse hydrological environment system of watershed, it is particularly important to couple the surface water and groundwater for better underding the entire hydrologic cycle. Guishui river basin, located in Beijing, was selected as the research area to build a MIKE SHE hydrological integrated model to simulate the surface runoff. The hydrologic response in the Guishui river basin was explored. This study will enrich the experience of the domestic application about MIKESHE model and provided scientific basis for regional water resources planning and management. In the paper, the development process and present research situation of integrated hydrological models were overviewed, concluding the principle of model structure. Considering the water environment issues in the study area (such as water pollution, water resource utilization, watershed underlying surface, climate change, etc.), the integrated hydrological model was setup based on MIKESHE for the simulation year of 2005 to 2010. The preliminary results showed that it is feasibile to apply the MIKESHE model in the study area for water environmental management. Furthermore, some valued suggestions and perspectives about the water environmental problems in the study for the future were provided.

Abstract: Through the Rough Model Method (RMM) an explicit calculation is proposed to solve the complex problem of the design of a pressurized trapezoidal shaped conduit characterized by three linear dimensions. Firstly, the method is applied to a rough model of the same shape in order to establish the equations governing its geometric and hydraulic characteristics. These equations are then secondly used to easily deduce the required linear dimensions of the current conduit by introducing a non-dimensional correction factor. The application of the obtained relationships requires only a strict minimum of data. All relationships provided in this article are applicable to the entire domain of the turbulent flow. Practical examples are taken to enable the hydraulic engineer to better understanding the advocated method and to observe the facility with which design of such a geometric profile can be performed.

Abstract: The evaluation of the effects of regulation engineering in Jiayu-Yanziwo reach is presented through the process of: (a) the introduction of study area and regulation works; (b) the establishment of a two-dimensional flow and sediment numerical model; (c) the evaluation of regulation works effects. According to the phenomenon of river process, a series of engineering to prevent the sand bar from erosion are designed. The effects of prevent works is simulated by 2D numerical model verified with measured data. After impound of the prevent engineering, the min navigation width while depth is 3.7m is greater than 150m, the good navigation conditions will maintained in next decade.

Abstract: The static and dynamic triaxial shear tests and deformation tests on CSG (cemented sand and gravel) are conducted with different amount of added cementing materials. The mechanical indexes and parameters have obvious increments with mixing of cementing material and accumulation of curing days. However the increments will become mild with further adding of cementing material. The deformation curve of CSG test sample is similar to the curve of sand-gravel sample without mixing with any cementing material, and they both follow the trend of semi-logarithmic decrement law. The dynamic permanent deformation of CSG increases with the increments of confining pressure, consolidation stress and dynamic stress. Thus this deformation still can be calculated using the constitutive model of dynamic residual deformation proposed by Zhujiang Shen Academician.