Applied Mechanics and Materials Vols. 438-439

Abstract: To establish reclaimed water system for the supply of urban miscellaneous water can alleviate water shortage in cities. For water-shortage cities, sewage recycling has especially significance. Based on the investigation into reclaimed water reuse in urban residential district, this paper explores a new path taking reclaimed water reuse as a new water-saving way to be applied in residential district, studies and analyzes the recyclable feasibility of reclaimed water system in the district, the choice of reclaimed water source, treatment technology and other aspects, and puts forward related suggestions. Some obstacles we have to overcome are also pointed out.

Abstract: On-site metrology calibration is of practical significance and necessity to promote the rational development and utilization of water resources and to strengthen the management of water metering facilities specification. In this paper, on-site flowmeter calibration method and principle is detailed with standard instrument comparison test, deviation control range of on-site metrology calibration measurement is proposed with the application of error theory. Standard instrument reference method is proved to meet on-site metrology calibration requirements by examples analysis. Further research orientation is also put forward.

Abstract: By tracing the performance of China Yellow-River Xiaolangdi Reservoir from operation to 2008, authors found: when the depth of sediment in reservoir tributary ditch mouth is less than 30m or when the length of sediment in reservoir tributary ditch mouth is less than 2km, tributary mouth bar usually will not form. However, when the depth of sediment in reservoir tributary ditch mouth is between 30m and 50m or when the length of sediment in reservoir tributary ditch mouth is less from 2km to 5km, tributary mouth bar tends to form. Moreover, sometimes the mouth bar will show up, disappear and then show up, disappear.

Abstract: Major factors that affect hydrodynamic character include confluence ratio, junction angle, bed discordance and channel gradient. In reservoir area, the river confluence is also affected by change of water level results from impoundment. Focused on asymmetrical confluence with 90° junction angle in reservoir area and based on model test, velocity distribution, location and range of reverse flow zone under different confluence ratios and water levels were investigated. The results show that flow velocity always declined along the channel after convergence. When confluence ratio increased, velocity decline rate accelerated, tributary flow diffused more fiercely at the conflux section, reverse flow zone enlarged. As the water level rising up, overall flow field velocity was weakened, the degree of tributary deflection increased. The velocity declined much slower in high water level.

Abstract: There are three characteristics of river channel which are wandering, transitional, bending in the Lower Yellow River. The fluvial process is complicated and variable. The channel characteristics of wandering reach was analyzed, and then based on the measured data and model test data, the formation conditions, basic characteristics and influencing factor of the fluvial process law in wandering river were analyzed. All of this can provide technical guidance and theoretical support for river regulation of the Lower Yellow River.

Abstract: The Kunlong Hydropower has high water head and complex geologic environment. It is necessary to study the seepage field and the seepage control measure. In order to set up a three dimensional seepage numerical model around the dam site, double fracture seepage systems contained main fractures network and fractured rock masses is adopted. Pipe to represent a drain hole and fissure to represent a line of holes methods are used in simulation of drainage curtain. After setting boundary conditions and calculating parameter appropriately, the whole seepage field around the Kunlong Dam is calculated with the finite element method. The optimal depths of the impervious curtain and drainage curtain are determined by sensitive analysis. The implications of the analysis results on the design of the project are significant.

Abstract: In this paper, the crack stability and crack propagation regularity of the upstream surface of super-high arch dam along the water-stop structure were analyzed in the framework of fracture mechanics. According to fracture toughness of dam concrete, the relationship between the crack propagation length and the allowable water pressure was studied. Finally, two main specific engineering suggestions for avoiding this kind of crack on the upstream surface of super-high arch dam were given: (1) the value of checking water pressure should not exceed 0.4 MPa; (2) the flange of the water-stop structure near the upstream surface of dam should be changed toward the downstream.

Abstract: A kind of crack with similar characteristics has been discovered on the upstream surface of super-high arch dam. In this paper, the reason of cracking was analyzed by the three-dimensional finite element method. It is found that the stress concentration of concrete near the water-stop structure led to the concrete initial cracking in the process of transverse joint open.

Abstract: This study main focuses on a real-time Zigbee-based localization system to provide prompt support for safety management in dam construction sites. The system accounts for a wireless sensor tracking technology and a set of servers running software for handling collected data, real-time site state visualization and remote interaction communications with other system such as ERP, CRM. The low-level tracking technology is a ZigBee-based network hardware utilizing fingerprinting software technology. The proposed real-time monitoring system for employer has been successfully implemented in Xiluodu arch dam construction site. The field tests also show that the RSSI-based localization algorithm implemented by ZigBee devices is reliable and is accurate (3 to 5 meters) enough. This real-time monitoring system was proven to be very useful for field safety management of high arch dam, and in similar hydraulic projects.

Abstract: Dam is the most important building in water conservancy, which generates enormously social and economic benefits in the national economy by providing green energy to all walks of the national daily life, and playing a important role in flood control for the safety of peoples lives and properties. However, as dam outburst will bring disastrous consequences to the downstream place, it is very important to ensure the safety of dam. By the large general software ANSYS for static analysis and the response spectrum analysis method for the dynamic analysis, this paper gives the security evaluation of a RCC gravity dam project, and provides some reference for similar engineering analysis.