Applied Mechanics and Materials Vols. 353-356

Abstract: Applicability and hydraulic evaluation of green revetment media which have improved physical structure are evaluated by the hydraulic model experiments. Results of the study on the relative erosion rates of base materials by the location of method and presence of vegetation, the green revetment had stability up to the limit of 1m distance, 1.5kg/m2 water pressure and 2 min of experimental duration. In addition, maintaining good rooting of vegetation would be beneficial to prevent erosion of revetment media during the flood as the resistance to the water pressure increases when the vegetation is applied in the river revetment.

Abstract: It cannot be ignored that the concrete surface of the discharge works may be seriously damaged caused by high speed flows. However, aerator installed at the bottom of spillway or tunnel is usually used to solve this problem in engineering. The function of the aeration facilities are influenced significantly by the cavity length and the backwater in the cavity, for the air holes will be blocked if there is a serious backwater in the cavity and so the aeration facilities will be ineffective. This thesis aims to study and analysis the relations among the air hole's area, the cavity length and the backwater depth in different conditions by the model experiments. The experiment results indicate that, the area of the air hole is a key factor to influence the jet cavity after the aerator. Aerator's body size and the chute slope affect cavity size and backwater in it greatly. For the chute with small bottom slope, more attention should be paid to the backwater in aerator's cavity.

Abstract: On the basis of different damage forms of surface water in coal mines, various prevention and control countermeasures to water hazard in different landforms, such as mountainous area, plain area and hilly area, were proposed. In general, the objects to be governed include river banks, plashes, slopes, gullies and surface collapses due to underground mining or karst cave to avoid the hazard. The principle is cutting off the relationship or passage between surface water and underground mining. Furthermore, advices and techniques on water passage detection were put forward to carry out the following work.

Abstract: In order to rationally use water resources and meet the demands of human society, long-distance water diversion project develops rapidly in recent years. However, its effects on the ecological environment resulting from construction and operation are becoming increasingly prominent and need to be solved. With the rapid development of the network, ITT has been widely used in various fields, providing great convenience for human life and social development. A case in point is the gradual application of the ITT to water conservancy. Through the analysis of the effects caused by long distance water diversion project on the ecological environment, this paper discusses the basic conditions of ITT application in hydraulic engineering and throws light on its application in ecological and environmental protection of long-distance water diversion project.

Abstract: The heat changes and distribution in water body provide one of the most important elements of structure influencing a host of chemical and biological processes. After the river-type reservoir was constructed, backwater entered into some tributaries, resulting in slow flow velocities in these tributaries. This paper made a reasonable description on the physical mechanism of hydrodynamic and water temperature distributions in a typical tributary bay, basing the hydrodynamic & water temperature coupled three-dimensional mathematical model. Through a large number of measured hydrologic, temperature and meteorological data, the paper simulated and obtained the hydrodynamic and water temperature distribution structure of the typical tributary bay and its evolution process, and described the hydrodynamic characteristics with precise values during the raising and falling temperature period; it is shown from the results that velocity vectors change displayed the water flow moved in a two-way circulation due to non-equilibrium warming and cooling on riverway cross-section, and the maximum flow velocity, turbulent kinetic energy and vorticity appeared on the surface water body, as well as wall near the tributary bay, and the turbulent kinetic energy is minimum on the center of tributary bay. The simulation experiment accurately captured the circulation phenomena caused by temperature difference, and proposed detailed distributions of flow field and related turbulent physical quantity, showed the strong coupling of flow field and temperature field change.

Abstract: Based on site investigation and annual survey data, the theoretical analysis method is applied to analyze the reach from Jiangxinzhou to Wujiang located at the lower reach of the Yangtze River. The characteristic of water flow and sediment and the macroscopic law of riverbed evolution are presented in this paper. In addition, the major factors influencing on the sandbar and beach evolution are also summarized. The results show that the riverbed evolution of the reach from Jiangxinzhou to Wujiang was caused by the linkage effects of main stream wandering near the Jiangxinzhou reach. The riverbed evolution of different waterways are interrelated and influenced with each other. Moreover, the main stream wandering at the inlet reach is one of the main reasons causing the riverbed evolution within the reach from Jiangxinzhou to Wujiang.

Abstract: The linear stability of triply diffusive convection in a binary Maxwell fluid saturated porous layer is investigated. Applying normal mode analysis , the criterion for the onset of stationary and oscillatory convection is obtained. The modified Darcy-Maxwell model is used as the analysis model. This allows us to make a thorough investigation of the processes of viscoelasticity and diffusions that causes the convection to set in through oscillatory rather than stationary. The effects of the parameters of Vadasz number, normalized porosity parameter, relaxation parameter, Lewis number and solute Rayleigh number are presented.

Abstract: Permeability coefficient is the determining factor for physical quantities in the seepage field, which can affect the distribution of all physical quantities including seepage flow. It took a hydropower station tail race as an object, founded FEM numerical model, analyzed the influence of permeability coefficients of cut-off wall and bedrock in non-uniform seepage and got the key factors affecting seepage flow. It provides the references in theory for design and construction of the tailrace.

Abstract: Baiyangdian wetland is the end of defence line to middlestream and downstream of Daqing river, and its geographic position has decided its critical function to flood control of Daqing river watershed. Therefore, according to the flood regulating ability of Baiyangdian, when the basin occur 50 year frequency flood, joint operation programs have been determined firstly, then the joint operation of Baiyangdian and multi-reservoir in parallel upstream have been presented through the pre-discharge regulation and real-time control discharge regulation, through comparison we determined the optimal combination scheme: joint scheduling with Wangkuai, Xidayang and Longmen upstream reservoirs,the storing water of reservoir can appropriately increased by reservoirs flood control capacity, thus we can not diversion flood to Wenanwa by Xiaoguan floodway, it can reduce the flood diversion of 1.62×10⁹ m³; and compared with conventional scheduling, we can reduce 8.57×10⁸ m³ flood diversion to the East wetland through Zaolinzhuang discharge gate. Therefore the flood flow into the flood diversion area reduced significantly, which have great practical significance to the safety of Baiyangdian wetlands surrounding areas and the important cities and towns downstream.

Abstract: Frost heaving damage of water conservancy project is widespread. Water migration is the principal factor, which influences the frost heaving characteristics of soil. In order to research the failure problems of hydraulic soil slope in dark seasonal frozen soil region, the layered water content is observed. It is researched that the rule of water migration characteristics. That offers theoretical basis and reference for construction of water conservancy project and guidance for engineering practice.